Hi,

I live in the Boston area and am currently considering purchasing a
house that has a combination of electric pump heat and propane heat.
Most of the houses I've lived in and seen in the area use either gas
or oil heat, so I wanted to get some opinions from the group regarding
these other types of home heating systems.

To provide a little more detail, this house was originally built in
the 80s with an electric heat pump. The owners installed a Rinnai
based propane system about 5 years ago to reduce their heating costs.
The Rinnai system is set up with propane tanks outside the house and 5
standing heating units around the house. Two of these units are
downstairs, two are in bedrooms upstairs, and one is in the basement.
Each of the heating units has its own thermostat. The house is large,
about 3500 square feet. There is no gas line to this house

My principle questions are around:

1. Can anyone comment on the electric heat pump? Boston gets fairly
cold and I've heard that these systems don't work well in very cold
weather.

2. Can anyone comment on Rinnai direct-vent heating systems? I've
never seen them around and wonder if there's a good reason for that.
Are they efficient? Are they safe? Is it safe to have big propane
tanks next to the house? What do I need to know here?

3. Presumably, I could install an oil based furnace if I wanted. Any
sense for how much something like that costs? Can oil based systems do
forced hot air, using the duct system that the electric pump already
has in place?

I've also asked for historic heating/electricity bills. It looks like
propane bills are $2000/year and electricity is about $4000/year. This
seems high to me, but obviously it's dependent on what the owner's
heat needs have been.

Appreciate any thoughts or comments... My initial thought is to walk
away from this, largely because I don't understand the systems and
don't like uncertainty. But I thought I'd get opinions from the group
to see if there are different thoughts.

Thanks,
PB

On Feb 11, 9:16*am, PB2 wrote:
Hi,

I live in the Boston area and am currently considering purchasing a
house that has a combination of electric pump heat and propane heat.
Most of the houses I've lived in and seen in the area use either gas
or oil heat, so I wanted to get some opinions from the group regarding
these other types of home heating systems.

To provide a little more detail, this house was originally built in
the 80s with an electric heat pump. The owners installed a Rinnai
based propane system about 5 years ago to reduce their heating costs.
The Rinnai system is set up with propane tanks outside the house and 5
standing heating units around the house. Two of these units are
downstairs, two are in bedrooms upstairs, and one is in the basement.
Each of the heating units has its own thermostat. The house is large,
about 3500 square feet. There is no gas line to this house

My principle questions are around:

1. Can anyone comment on the electric heat pump? Boston gets fairly
cold and I've heard that these systems don't work well in very cold
weather.

2. Can anyone comment on Rinnai direct-vent heating systems? I've
never seen them around and wonder if there's a good reason for that.
Are they efficient? Are they safe? Is it safe to have big propane
tanks next to the house? What do I need to know here?

3. Presumably, I could install an oil based furnace if I wanted. Any
sense for how much something like that costs? Can oil based systems do
forced hot air, using the duct system that the electric pump already
has in place?

I've also asked for historic heating/electricity bills. It looks like
propane bills are $2000/year and electricity is about $4000/year. This
seems high to me, but obviously it's dependent on what the owner's
heat needs have been.

Appreciate any thoughts or comments... My initial thought is to walk
away from this, largely because I don't understand the systems and
don't like uncertainty. But I thought I'd get opinions from the group
to see if there are different thoughts.

Thanks,
PB

I have the opposite; a propane furnace with electric HVAC in a 2 story
addition. I like the balance, My fuel use is necessarily less in
Texas, & heat pumps work well here at least until it dips below 30,
then emergency heat kicks in at a lot more $ per hr. I think this is
what the previous owner had in mind, just something to keep the
heating coils from kicking on. I could see how this could be managed
to not eat you out of house and home; set the unused rooms back to say
55 degrees & only bump them up when using them, lock out the emergency
heat on the heat pump, all that could be done with smart thermostats.
My electric heat is in the form of PTACs (motel units) & those work
well if equipped with remote thermostats, the on board ones are always
confused due to being right inside the unit. I had never encountered a
dual fuel house before I moved here, but saw the wisdom of it the
first time we ran out of propane (rookie mistake), and the first time
we had a power outage (I still got my shower the addition has its own
electric water heater).

On Feb 11, 10:16�am, PB2 wrote:


My principle questions are around:

1. Can anyone comment on the electric heat pump? Boston gets fairly
cold and I've heard that these systems don't work well in very cold
weather.

2. Can anyone comment on Rinnai direct-vent heating systems? I've
never seen them around and wonder if there's a good reason for that.
Are they efficient? Are they safe? Is it safe to have big propane
tanks next to the house? What do I need to know here?

3. Presumably, I could install an oil based furnace if I wanted. Any
sense for how much something like that costs? Can oil based systems do
forced hot air, using the duct system that the electric pump already
has in place?


I assume your heat pump doubles as an air conditioning system
also.....correct?

The heat pump is only effecient down to about 35 degrees. Also, the
heat from a heat pump just isn't like flame heat. You still feel cool.
Lack of humidity?

In my area, propane is more expensive than natural gas. I don't know
about oil. Propane tanks are safe if not ran into by a big truck. :-)

Hank

PB2 wrote:
....
I live in the Boston area and am currently considering purchasing a
house that has a combination of electric pump heat and propane heat.
Most of the houses I've lived in and seen in the area use either gas
or oil heat, so I wanted to get some opinions from the group regarding
these other types of home heating systems.

To provide a little more detail, this house was originally built in
the 80s with an electric heat pump. The owners installed a Rinnai
based propane system about 5 years ago to reduce their heating costs.
The Rinnai system is set up with propane tanks outside the house and 5
standing heating units around the house. Two of these units are
downstairs, two are in bedrooms upstairs, and one is in the basement.
Each of the heating units has its own thermostat. The house is large,
about 3500 square feet. There is no gas line to this house

My principle questions are around:

1. Can anyone comment on the electric heat pump? Boston gets fairly
cold and I've heard that these systems don't work well in very cold
weather.

2. Can anyone comment on Rinnai direct-vent heating systems? I've
never seen them around and wonder if there's a good reason for that.
Are they efficient? Are they safe? Is it safe to have big propane
tanks next to the house? What do I need to know here?

3. Presumably, I could install an oil based furnace if I wanted. Any
sense for how much something like that costs? Can oil based systems do
forced hot air, using the duct system that the electric pump already
has in place?

I've also asked for historic heating/electricity bills. It looks like
propane bills are $2000/year and electricity is about $4000/year. This
seems high to me, but obviously it's dependent on what the owner's
heat needs have been.

Appreciate any thoughts or comments... My initial thought is to walk
away from this, largely because I don't understand the systems and
don't like uncertainty. But I thought I'd get opinions from the group
to see if there are different thoughts.

Although you don't say, this obviously is an air-exchange heat pump; a
markedly poor choice for Boston w/ the initial (again apparent)
resistance "emergency" heat.

The need for an alternate fuel source is apparent given electric rates
in the NE (altho there may be a break for heat pumps; check w/ the
utility to see, but I'd not expect it to be enough to solve the problem).

Propane is the alternate fuel source where there isn't an access to
natural gas but is also significantly more expensive (and is only going
to get more so imo). If the installation is proper, there's no real
safety hazard although propane is unlike gas in that it is heavier than
air so there are some precautions/code requirements that are different
owing to that behavior difference.

I don't know the Renai (sp?)--can't comment. I would presume the
efficiency questions, etc., could be answered by looking at their web
site/contacting them for information. Are these unvented? I'd not like
that, particularly in a really cold climate.

I'd tend to walk on this setup myself, too, unless there are really
other things that make it a bargain. Particularly if this heat pump is
very old, it's probably on the short list for replacement anyway as well.

--

On Feb 11, 3:31*pm, "Hustlin' Hank" wrote:

I assume your heat pump doubles as an air conditioning system
also.....correct?

Appreciate the comments. Yes, that's correct - it doubles as an A/C
system.

PB2 wrote in news:71782e37-4840-4355-8e9c-
:

Hi,

I live in the Boston area and am currently considering purchasing a
house that has a combination of electric pump heat and propane heat.
Most of the houses I've lived in and seen in the area use either gas
or oil heat, so I wanted to get some opinions from the group regarding
these other types of home heating systems.

To provide a little more detail, this house was originally built in
the 80s with an electric heat pump. The owners installed a Rinnai
based propane system about 5 years ago to reduce their heating costs.
The Rinnai system is set up with propane tanks outside the house and 5
standing heating units around the house. Two of these units are
downstairs, two are in bedrooms upstairs, and one is in the basement.
Each of the heating units has its own thermostat. The house is large,
about 3500 square feet. There is no gas line to this house

My principle questions are around:

1. Can anyone comment on the electric heat pump? Boston gets fairly
cold and I've heard that these systems don't work well in very cold
weather.

2. Can anyone comment on Rinnai direct-vent heating systems? I've
never seen them around and wonder if there's a good reason for that.
Are they efficient? Are they safe? Is it safe to have big propane
tanks next to the house? What do I need to know here?

3. Presumably, I could install an oil based furnace if I wanted. Any
sense for how much something like that costs? Can oil based systems do
forced hot air, using the duct system that the electric pump already
has in place?

I've also asked for historic heating/electricity bills. It looks like
propane bills are $2000/year and electricity is about $4000/year. This
seems high to me, but obviously it's dependent on what the owner's
heat needs have been.

Appreciate any thoughts or comments... My initial thought is to walk
away from this, largely because I don't understand the systems and
don't like uncertainty. But I thought I'd get opinions from the group
to see if there are different thoughts.

Thanks,
PB

Sounds like the place had had historic HVAC issues and/or cost issues
with them since the setup is not typical there. I suspect the owner
is/was trying to avoid the expense of "...install an oil based furnace if
I wanted.".

It adds to the cost of your purchase indirectly. There is no recoup for
changing it unless you are getting a heavy discount. Keep in mind oil was
getting up to the $5/gal mark and sure to return there or worse. Propane
is probably expensive there and maybe was a bargain whe oil price was up.

I think I'd walk on that one. Avoid the discomfort and expense.
Remember, if you sell someday, buyers will have the same concerns as you.
Many potentials will avoid considering the home because of the setup.

On Feb 11, 7:36�pm, Bubba wrote:


The heat pump is only effecient down to about 35 degrees.

Sorry Hank. That sentence above from you was a totally stupid bull****
statement from one that has no idea what a heat pump can do.
Bubba



To call my reply "stupid bull****" isn't winning you any friends.

I had a heat pump in my last house 4 years ago. I stand by my
statement that it is only efficient down to "about" 35 degrees. Below
that, it is cheaper to use other heating methods. I didn't say it
wouldn't heat below 35, it just isn't economical. Check the facts.

"Feeling warm" is a matter of opinion. I like to sit around in a t-
shirt, so, it wasn't warm to me. I may have felt warm if I'd wear a
sweat shirt. Why do people like fireplaces? I'll tell you. Because it
makes "them" feel warm.

Hank ~~~wonders if there is "smart bull****"

On Feb 12, 10:15*am, Bubba wrote:
On Thu, 12 Feb 2009 00:40:37 -0800 (PST), "Hustlin' Hank"





wrote:
On Feb 11, 7:36?pm, Bubba wrote:

The heat pump is only effecient down to about 35 degrees.

Sorry Hank. That sentence above from you was a totally stupid bull****
statement from one that has no idea what a heat pump can do.
Bubba

To call my reply "stupid bull****" isn't winning you any friends.

I had a heat pump in my last house 4 years ago. I stand by my
statement that it is only efficient down to "about" 35 degrees. Below
that, it is cheaper to use other heating methods. I didn't say it
wouldn't heat below 35, it just isn't economical. Check the facts.

"Feeling warm" is a matter of opinion. I like to sit around in a t-
shirt, so, it wasn't warm to me. I may have felt warm if I'd wear a
sweat shirt. Why do people like fireplaces? I'll tell you. Because it
makes "them" feel warm.

Hank ~~~wonders if there is "smart bull****"

Sorry Hank but I still call your reply TOTAL BULL****! What does that
have to do with winning friends?
Simple test. There are all kinds of papers that came with your heat
pump when it was installed (if not, you can find them online.) One of
those has the performance data for your heat pump. Check them out.
Heat pumps can be very efficient even down to 0 degrees depending on
your model. Look at the COP's at the lower temps. IF you dont know
what that is then you dont need to be commenting.
Bubba- Hide quoted text -

- Show quoted text -


Let's see what some others have to say about the efficiency of heat
pumps as the outside temps drop:

http://www.hannabery.com/faq4.shtml

Hannabery HVAC, Pennsylvania
Now with 4 locations Serving Eastern Pennsylvania Homeowners and
Businesses for over 30 years!

"In other words, if you set your thermostat for 71 degrees in the
winter and your house only seems to get up to 69 degrees. This problem
generates many service calls. And sometimes this is caused by a
genuine problem but unfortunately, in extremely, cold weather even a
properly working heat pump may have trouble maintaining desired
temperature.
Why is this? When it gets below a certain temperature, in our area
around 35 degrees a heat pump loses efficiency and cannot keep up with
the heat loss of the structure. "


Which is exactly what Hank stated. BTW, Bubba, Mr. HVAC Pro, where's
your website?


Or how about this, from an electric company:

http://www.horryelectric.com/article...&articleID=892

"2. Auxiliary heat light “ON” (located on thermostat).
• Supplimentary heaters are providing heat (usually
when outside temperature is lower than the balance
point, generally 35° or less)."


Oh wait, it gets better. Here they address how with a heat pump, the
air coming out of the registers will feel cooler than other heating
systems. Which is something else Hank stated, which compelled you to
call him names:

"The coils of your heat pump operate at lower heat levels than
fossil fuel systems. Air at the supply grills almost always has a
temperature ranging from 85° to 106°F in the winter. Air at the
registers may feel cool compared to that from other heating
systems which operate at much higher temperatures for a shorter
length of time."


Or how about this from the Dept of Energy:

http://apps1.eere.energy.gov/consume.../mytopic=12620

"When outdoor temperatures fall below 40°F, a less-efficient panel of
electric resistance coils, similar to those in your toaster, kicks in
to provide indoor heating. This is why air-source heat pumps aren't
always very efficient for heating in areas with cold winters. Some
units now have gas-fired backup furnaces instead of electric
resistance coils, allowing them to operate more efficiently"

"Although air-source heat pumps can be used in nearly all parts of the
United States, they do not generally perform well over extended
periods of sub-freezing temperatures. In regions with sub-freezing
winter temperatures, it may not be cost effective to meet all your
heating needs with a standard air-source heat pump."

Now, who should know more about energy and efficiency? The DOE or
Bubba?

Now, who should know more about energy and efficiency? * The DOE or
Bubba?- Hide quoted text -

- Show quoted text -

efficiency and effectiveness are NOT the same thing...

My heat pump is not very EFFECTIVE below 32 becasue it does not keep
my house comforatbale but it is still pretty EFFICIENT. Below 32,
the BTU that it puts out drops but so does the electric power that it
pulls.

Below 32, I switch off the heat pump and use oil.

Mark

wrote:
....
Or how about this from the Dept of Energy:

http://apps1.eere.energy.gov/consume.../mytopic=12620

"When outdoor temperatures fall below 40°F, a less-efficient panel of
electric resistance coils, similar to those in your toaster, kicks in
to provide indoor heating. This is why air-source heat pumps aren't
always very efficient for heating in areas with cold winters. Some
units now have gas-fired backup furnaces instead of electric
resistance coils, allowing them to operate more efficiently"
....

That in particular is a terribly poorly worded paragraph; one would hope
DOE would do better.

The electric resistance heaters are nearly 100% efficient; certainly
higher efficiency than the gas furnace. What they're really talking
about is cost effectiveness, not efficiency.

--

On Feb 12, 1:16*pm, wrote:
Now, who should know more about energy and efficiency? * The DOE or
Bubba?- Hide quoted text -

- Show quoted text -

efficiency and effectiveness are NOT the same thing...

My heat pump is not very EFFECTIVE below 32 becasue it does not keep
my house comforatbale but it is still pretty EFFICIENT. * *Below 32,
the BTU that it puts out drops but so does the electric power that it
pulls.

Below 32, I switch off the heat pump and use oil.

Mark



I would have to disagree that the lower the temperature the less
electricity a heat pump will use. The efficiency of a heat pump DOES
decline almopst linearly with decreasing temperature. In other
words, for every KWH of electricity you put in it, you get more heat
out at 45F than you do at 25F. If it were not so, then you could
just put in larger capacity heat pumps and cost effectively heat homes
where it was regularly 0 degrees, no?

On Feb 12, 1:08*pm, wrote:
On Feb 12, 1:16*pm, wrote:

Now, who should know more about energy and efficiency? * The DOE or
Bubba?- Hide quoted text -

- Show quoted text -

efficiency and effectiveness are NOT the same thing...

My heat pump is not very EFFECTIVE below 32 becasue it does not keep
my house comforatbale but it is still pretty EFFICIENT. * *Below 32,
the BTU that it puts out drops but so does the electric power that it
pulls.

Below 32, I switch off the heat pump and use oil.

Mark

I would have to disagree that the lower the temperature the less
electricity a heat pump will use. * The efficiency of a heat pump DOES
decline almopst linearly with decreasing temperature. * In other
words, for every KWH of electricity you put in it, you get more heat
out at 45F than you do at 25F. * If it were not so, then you could
just put in larger capacity heat pumps and cost effectively heat homes
where it was regularly 0 degrees, no?

I don't know about cost effective, but I oversize my PTAC units & get
heat hopefully at lower temperatures.
I upgraded both of my units mainly because the newer ones were higher
seer ratings. I also bought bigger units, somewhat oversize for the
area,
Both the upstairs and downstairs units seem to keep up nicely both hot
and cool they dehumidify on AC so I guess I didn't go too far.
I have no alternate in that part of the house, the gas furnace is
ducted there,
and I guess that was the original plan, but the ducts are just too
long to be effective, so I blocked them off.
There is a natural convection from the original one story to the 2
story, but it isn't enough for comfort

On Feb 12, 2:08*pm, wrote:
On Feb 12, 1:16*pm, wrote:

Now, who should know more about energy and efficiency? * The DOE or
Bubba?- Hide quoted text -

- Show quoted text -

efficiency and effectiveness are NOT the same thing...

My heat pump is not very EFFECTIVE below 32 becasue it does not keep
my house comforatbale but it is still pretty EFFICIENT. * *Below 32,
the BTU that it puts out drops but so does the electric power that it
pulls.

Below 32, I switch off the heat pump and use oil.

Mark

I would have to disagree that the lower the temperature the less
electricity a heat pump will use. * The efficiency of a heat pump DOES
decline almopst linearly with decreasing temperature. * In other
words, for every KWH of electricity you put in it, you get more heat
out at 45F than you do at 25F. * If it were not so, then you could
just put in larger capacity heat pumps and cost effectively heat homes
where it was regularly 0 degrees, no?

the issue I have is that below 32 the outdoor coils will freeze up and
the thing has to go through a defrost cycle, at that point i say
forget it and switch to oil..

yes due to the defrost cycle the system is less effeicent. I think
the COP at 32 is still probably 2 and above 32 it gets better...

So at 32 it is still cheaper to run then oil and at 45 or so it is
much cheaper to run then oil.

I guess if you count the defrost cycle, then yes it gets a lot less
efficient below 32.


Mark

On Feb 12, 3:57*pm, Bubba wrote:
On Thu, 12 Feb 2009 08:00:07 -0800 (PST), wrote:
On Feb 12, 10:15*am, Bubba wrote:
On Thu, 12 Feb 2009 00:40:37 -0800 (PST), "Hustlin' Hank"

wrote:
On Feb 11, 7:36?pm, Bubba wrote:

The heat pump is only effecient down to about 35 degrees.

Sorry Hank. That sentence above from you was a totally stupid bull****
statement from one that has no idea what a heat pump can do.
Bubba

To call my reply "stupid bull****" isn't winning you any friends.

I had a heat pump in my last house 4 years ago. I stand by my
statement that it is only efficient down to "about" 35 degrees. Below
that, it is cheaper to use other heating methods. I didn't say it
wouldn't heat below 35, it just isn't economical. Check the facts.

"Feeling warm" is a matter of opinion. I like to sit around in a t-
shirt, so, it wasn't warm to me. I may have felt warm if I'd wear a
sweat shirt. Why do people like fireplaces? I'll tell you. Because it
makes "them" feel warm.

Hank ~~~wonders if there is "smart bull****"

Sorry Hank but I still call your reply TOTAL BULL****! What does that
have to do with winning friends?
Simple test. There are all kinds of papers that came with your heat
pump when it was installed (if not, you can find them online.) One of
those has the performance data for your heat pump. Check them out.
Heat pumps can be very efficient even down to 0 degrees depending on
your model. Look at the COP's at the lower temps. IF you dont know
what that is then you dont need to be commenting.
Bubba- Hide quoted text -

- Show quoted text -

Let's see what some others have to say about the efficiency of heat
pumps as the outside temps drop:

http://www.hannabery.com/faq4.shtml

Hannabery HVAC, Pennsylvania
Now with 4 locations Serving Eastern Pennsylvania Homeowners and
Businesses for over 30 years!

"In other words, if you set your thermostat for 71 degrees in the
winter and your house only seems to get up to 69 degrees. This problem
generates many service calls. And sometimes this is caused by a
genuine problem but unfortunately, in extremely, cold weather even a
properly working heat pump may have trouble maintaining desired
temperature.
Why is this? When it gets below a certain temperature, in our area
around 35 degrees a heat pump loses efficiency and cannot keep up with
the heat loss of the structure. "

Which is exactly what Hank stated. *BTW, Bubba, Mr. HVAC Pro, where's
your website?

Or how about this, from an electric company:

http://www.horryelectric.com/article...&articleID=892

"2. Auxiliary heat light “ON” (located on thermostat).
• Supplimentary heaters are providing heat (usually
when outside temperature is lower than the balance
point, generally 35° or less)."

Oh wait, it gets better. *Here they address how with a heat pump, the
air coming out of the registers will feel cooler than other heating
systems. * Which is something else Hank stated, which compelled you to
call him names:

"The coils of your heat pump operate at lower heat levels than
fossil fuel systems. Air at the supply grills almost always has a
temperature ranging from 85° to 106°F in the winter. Air at the
registers may feel cool compared to that from other heating
systems which operate at much higher temperatures for a shorter
length of time."

Or how about this from the Dept of Energy:

http://apps1.eere.energy.gov/consume...eating_cooling...

"When outdoor temperatures fall below 40°F, a less-efficient panel of
electric resistance coils, similar to those in your toaster, kicks in
to provide indoor heating. This is why air-source heat pumps aren't
always very efficient for heating in areas with cold winters. Some
units now have gas-fired backup furnaces instead of electric
resistance coils, allowing them to operate more efficiently"

"Although air-source heat pumps can be used in nearly all parts of the
United States, they do not generally perform well over extended
periods of sub-freezing temperatures. In regions with sub-freezing
winter temperatures, it may not be cost effective to meet all your
heating needs with a standard air-source heat pump."

Now, who should know more about energy and efficiency? * The DOE or
Bubba?

Once again Trader, you show your incompetence. You obviously dont
understand energy and what it costs and what it does.
A heat pump is a very efficient machine. It uses electricity but at a
much better efficiency than if you were to use just straight electric
strip heaters. Sometimes at almost a 4 to 1 ratio.


No s*** Sherlock. You figure that out all by yourself? The piece
you're missing here is that amount of heat that you get for the amount
of electricity consumed declines as the temp differential between the
inside temp and the outside temp increases. In other words, heat
pumps become LESS EFFICIENT the lower the outside temp. Which is
exactly the point Hank was making when you called his post stupid BS.
It depends on the relative cost of the electric and the alternative
fuels, but in many cases below 35, it costs less to use other fuels,
like natural gas. Which is why air based heat pumps are not
generally used in cold northern climates. Or if they are used, they
have a duel fuel system, like nat gas. Maybe you haven't noticed. If
you paid attention, the discussion was about Boston. In fact, that
is exactly what the OP has. A heat pump system with additional heat
from propane.

And once again, I give you links to HVAC companies and the DOE that
back up both points of Hank's post, and you just ignore it.





My heat pump warms
my house very well at 35 degrees. Piece of cake actually. Certainly
the air coming out of the registers is cooler than a gas, or oil
furnace. But guess what? It does heat the house to what temp I want it
at when its 35 degrees outside and even lower.

The obvious point Hank was making is that below somewhere around 35,
the efficiency of the heat pump has dropped so that you'd spend less
money using another fuel, like nat gas.


It also uses less and
less electricity, the colder it gets outside but in turn produces less
btu's of heat.

It's using MORE electricity per BTU of heat that's being generated in
the house. That's all that anyone cares about. My gas furnace would
use zero fuel too, if it wasn't putting out any heat.


Then, some magic happens.

I can understand how it seems like magic to someone like you, who
eschews science, engineering and education.



At a certain point, (it
happens to be called the balance point of the home), the heat pump can
no longer keep up with the heating needs of the house and the backup
heat takes over. Is this all to hard for you trader? I know this is
all way over your head trader but please try to follow along. Maybe
one day you will actually learn something and I might even let you be
like me.
35 degrees?! Wow Trader. You are one dumb sonz-a-biatch.
Do I need to point you to one of the performance specs of a heat pump
so you can understand what heat a heat pump can produce?
Bubba- Hide quoted text -


Just glad I never have to let a hack like you anywhere near my house.

On Feb 12, 3:57�pm, Bubba wrote:


Once again Trader, you show your incompetence. You obviously dont
understand energy and what it costs and what it does.
A heat pump is a very efficient machine. It uses electricity but at a
much better efficiency than if you were to use just straight electric
strip heaters. Sometimes at almost a 4 to 1 ratio. My heat pump warms
my house very well at 35 degrees. Piece of cake actually. Certainly
the air coming out of the registers is cooler than a gas, or oil
furnace. But guess what? It does heat the house to what temp I want it
at when its 35 degrees outside and even lower. Is this all to hard for you trader? I know this is
all way over your head trader but please try to follow along. Maybe
one day you will actually learn something and I might even let you be
like me.
35 degrees?! Wow Trader. You are one dumb sonz-a-biatch.
Do I need to point you to one of the performance specs of a heat pump
so you can understand what heat a heat pump can produce?
Bubba-

Someone's a little confused here, and it isn't Trader. By the way,
thanks Trader for helping me try to edgeumacate Bubba. :-)

How can you make the statement "It also uses less and less
electricity, the colder it gets outside but in turn produces less
btu's of heat. Then, some magic happens. At a certain point, (it
happens to be called the balance point of the home), the heat pump
can
no longer keep up with the heating needs of the house and the backup
heat takes over." ?

The colder it gets the MORE the heat pump runs, not less. How could
that use "less" electric? Why do you think the so called "magic"
happens? It happens because the manufacturer KNOWS it is more
efficient (cheaper) to heat with electric resistive, gas, oil, or
anything else. So they have the heat pump kick off at ABOUT 35
degrees. Now, will the heat pump heat below 35 degrees? Yes it will,
but not cost effective.

Hank ~~~hates to 'splain em.

The colder it gets the MORE the heat pump runs, not less. How could
that use "less" electric? Why do you think the so called "magic"
happens? It happens because the manufacturer KNOWS it is more
efficient (cheaper) to heat with electric resistive, gas, oil, or
anything else. So they have the heat pump kick off at ABOUT 35
degrees. Now, will the heat pump heat below 35 degrees? Yes it will,
but not cost effective.

Hank ~~~hates to 'splain em.- Hide quoted text -

- Show quoted text -

it uses less electricity per minute.. yes of course it runs more and
uses more electricity overall. And Trader let me clarify what I
said, I agree w/ you a heat pum does get less effeictn when its
colder out, but it is still pretty effeicent compared to other forms
of heat. The reason it sucks below 32 is not becasue the effeiceny is
so bad but becasue its effectivlness is so bad, it does not put out
enough heat.

like this:

at 45deg its 400% effeciency and uses X kW and puts out 40,000 BTU/hr
and works great.

at 25 its 200% efficency and uses X/1.5 kW puts out 20,000 BTU/hr...,
the power consumed (per minute) when down, the heat output went down
even more, but thats still more effecenct compared to resistive heat
(which is 100% effeceinct. But the 20,000 BTU/hr is not enough to keep
the house warm so it no long is EFFECTIVE.

and when you throw in the defrost cycles its a looser.

Mark

On Feb 13, 8:08*am, wrote:
The colder it gets the MORE the heat pump runs, not less. How could
that use "less" electric? Why do you think the so called "magic"
happens? It happens because the manufacturer KNOWS it is more
efficient (cheaper) to heat with electric resistive, gas, oil, or
anything else. So they have the heat pump kick off at ABOUT 35
degrees. Now, will the heat pump heat below 35 degrees? Yes it will,
but not cost effective.

Hank ~~~hates to 'splain em.- Hide quoted text -

- Show quoted text -

it uses less electricity per minute.. *yes of course it runs more and
uses more electricity overall. *And Trader let me clarify what I
said, * I agree w/ you a heat pum does get less effeictn when its
colder out, but it is still pretty effeicent compared to other forms
of heat. *The reason it sucks below 32 is not becasue the effeiceny is
so bad but becasue its effectivlness is so bad, it does not put out
enough heat.

If that were the case, then the obvious solution would be to just use
a bigger heat pump or two heat pumps. But the problem is that
somewhere around 32 and below, other forms of energy are more cost
effective, ie nat gas or oil, because the efficiency of a heat pump
declines linearly with decreasing outside temp. Now a heat pump
could still be an overall good solution, it just depends on how much
of the time the temperature is below 32. If it only occasionally gets
down to say 20, then the higher efficiency that you have most of the
time more than offsets the higher cost at the lower temps for brief
periods, so you come out ahead. On the other hand, if you
regularly have 0 to 20 deg periods, then another fuel like gas or oil
could be better. Of course, it depends on the actual cost of
electricity vs the other fuel in the paricular area. Or a dual fuel
system could be an option.

I think the above is exactly what Hank's comments were about.




like this:

at 45deg *its 400% effeciency and uses X kW and puts out 40,000 BTU/hr
and works great.

at 25 its 200% efficency and uses X/1.5 kW puts out 20,000 BTU/hr...,
the power consumed (per minute) when down, the heat output went down
even more, but thats still more effecenct compared to resistive heat
(which is 100% effeceinct. But the 20,000 BTU/hr is not enough to keep
the house warm so it no long is EFFECTIVE.

and when you throw in the defrost cycles its a looser.

Mark

Agree in principle with what you're saying above. But also at some
point, which could be at or around 25, even if the heat pump were
large enough so that it could produce all the heat required, other
fuels, like nat gas or oil are cheaper to use due to the declining
efficiency of the heat pump at lower temps. So if you were to be at
that temp or below a lot of the time, then those other fuels are
cheaper to use than the heat pump. Also, in additon to the defrost
cycles, if you rely on electric resistance heating to supplement,
then it becomes a big loser.

On Feb 13, 8:14*am, Bubba wrote:
?

Once again Trader, you show your incompetence. You obviously dont
understand energy and what it costs and what it does.
A heat pump is a very efficient machine. It uses electricity but at a
much better efficiency than if you were to use just straight electric
strip heaters. Sometimes at almost a 4 to 1 ratio.

No s*** Sherlock. *You figure that out all by yourself? * *The piece
you're missing here is that amount of heat that you get for the amount
of electricity consumed declines as the temp differential between the
inside temp and the outside temp increases. *In other words, heat
pumps become LESS EFFICIENT the lower the outside temp. * Which is
exactly the point Hank was making when you called his post stupid BS.
It depends on the relative cost of the electric and the alternative
fuels, but in many cases below 35, it costs less to use other fuels,
like natural gas. * *Which is why air based heat pumps are not
generally used in cold northern climates. *Or if they are used, they
have a duel fuel system, like nat gas. Maybe you haven't noticed. * If
you paid attention, the discussion was about Boston. * In fact, that
is exactly what the OP has. *A heat pump system with additional heat
from propane.

And once again, I give you links to HVAC companies and the DOE that
back up both points of Hank's post, and you just ignore it.

and once again I have to point out that your thinking ignores the
facts. With all the horse crap you have pointed out once again quoting
DOE and hanna-barbarra land and an electrical company, etc.


Funny how according to you everyone from the Dept of Energy, to
Aprilaire, to HVAC companies that have been in business for 30 years
are all full of crap. BTW, where are the links that support any of
your claims?




I will
give you a real life situation.
You think that at 35 degrees a heat pump seems relatively useless.

Never said any such thing. Only that the efficiency of a heat pump
declines as the temperature outside decreases. And at some point,
below around 35 degrees or so, other fuels like gas or oil can produce
the same amount of heat for less money than it costs to run the heat
pump.



Last night, as luck would have it, It got down to below 35 degrees
here in the land of make belive in Cincinnati. My Honeywell Vision Pro
IAQ stat showed 35 but looking at the frozen water on my pool cover
tells me it was closer to 30.

Gee, sounds like the Vision Pro thermostat is broken. You should
call a competent HVAC guy and get that fixed pronto.


I turned the gas off to my furnace last
night and just let my 14 SEER heat pump do its job. I have a 1950's
home with brick and block construction (no insulation in the walls)
and R-38 blown into the attic. The uninsulated basement is about 75%
below grade.
NOW, tell me OH Wonderous one with an obviously useless EE degree.
How is it that my useless heat pump as you call them maintained 67
degrees last night in my home while the temp outside was around 30??

Show us once where I ever said a heat pump was useless at 30 deg. I
only said that the efficiency of the heat pump declines with temp, and
below somewhere around 35 deg other fuels, like nat gas, become more
cost effective.




Also tell me how my system was able to regularly cycle on and off all
night , all the while when it went into defrost it was pumping in that
additional cold air since I had my gas heat shut off?

My heat pump warms
my house very well at 35 degrees. Piece of cake actually. Certainly
the air coming out of the registers is cooler than a gas, or oil
furnace. But guess what? It does heat the house to what temp I want it
at when its 35 degrees outside and even lower.

Never said it wouldn;t warm your house at 35.




The obvious point Hank was making is that below somewhere around 35,
the efficiency of the heat pump has dropped so that you'd spend less
money using another fuel, like nat gas.

and you are wrong wrong wrong just like Hank.


So, says you. Then tell us why we don't just use bigger heat pumps
that can supply enough heat for a house to be 70 when it's 0 outside?
All of MN should have them. And why all the fuss about
geothermal? Hmmm? If you can just as efficiently extract heat from
10 deg temps as from 50 deg temps, then why go to all that trouble of
using 50 deg groundwater?






It also uses less and
less electricity, the colder it gets outside but in turn produces less
btu's of heat.

It's using MORE electricity per BTU of heat that's being generated in
the house. * That's all that anyone cares about. *My gas furnace would
use zero fuel too, if it wasn't putting out any heat.

and again, you are wrong wrong wrong. I'll look up my performance
chart for you and show you later.


Everyone else here agrees that heat pumps use more electricity per
BTU of heat generated as the outside temp drops. Hank, Mark, DOE,
the HVAC company. I could give you 50 more links. Again, you're in
your own little universe where the laws of physics no longer apply.
I'd like to see a link from anywhere that says the efficiency of a
heat pump does not decline as the outside temp drops.

On Feb 13, 8:01�am, Bubba wrote:


Hank,
Do me a favor. Go buy, rent or borrow an Amprobe. Its a cute little
device that simply clamps around an electric line and measures the
amount of amps running through a wire.
Put it on the wire going to your compressor (Common or Run) wire and
turn the heat pump on when it is, lets say around 55 degrees outside.
Now, try it another day when it is maybe 20 degrees outside.
Come back when you can intelligently explain to me why the amperage
reading is significantly lower when it is cold outside.
Bubba
Me really hates training the untrainable ones-

First: I don't have a heat pump in the house I am in now, so checking
the amps is impossible for me to do.

Second: I am not a HVAC installer, repairman, engineer or salesman.

Third: I have been a user of heat pumps and my impression as a "user"
is stated in one of my previous posts. I'll say it again, I don't like
them.

Fourth: I think we MAY be arguing apples and oranges and you mis-
understood (or I didn't explain it correctly) my original comments.

Fifth: ( Trying to explain my point again, altho most understood) I
was saying the word "efficiency" and maybe I should have said
"effectiveness" in regards to COST.

Sixth: You cannot convince me that a heat pump can save me money below
35 degrees in Ohio. I am up the road from you in Columbus, so I know
the weather.

Seventh: I appogize for any mis-understanding on my part.

Eighth: I got nuthin' for 8.

Hank

On Feb 13, 4:26*pm, "Hustlin' Hank" wrote:
On Feb 13, 8:01 am, Bubba wrote:



Hank,
Do me a favor. Go buy, rent or borrow an Amprobe. Its a cute little
device that simply clamps around an electric line and measures the
amount of amps running through a wire.
Put it on the wire going to your compressor (Common or Run) wire and
turn the heat pump on when it is, lets say around 55 degrees outside.
Now, try it another day when it is maybe 20 degrees outside.
Come back when you can intelligently explain to me why the amperage
reading is significantly lower when it is cold outside.
Bubba
Me really hates training the untrainable ones-

First: I don't have a heat pump in the house I am in now, so checking
the amps is impossible for me to do.

Second: I am not a HVAC installer, repairman, engineer or salesman.

Third: I have been a user of heat pumps and my impression as a "user"
is stated in one of my previous posts. I'll say it again, I don't like
them.

Fourth: I think we MAY be arguing apples and oranges and you mis-
understood (or I didn't explain it correctly) my original comments.

Fifth: ( Trying to explain my point again, altho most understood) I
was saying the word "efficiency" and maybe I should have said
"effectiveness" in regards to COST.

Sixth: You cannot convince me that a heat pump can save me money below
35 degrees in Ohio. I am up the road from you in Columbus, so I know
the weather.

Seventh: I appogize for *any mis-understanding on my part.

Eighth: I got nuthin' for 8.

Hank


Ninth:

Even if you did what Bubba asked, he doesn't even realize it would not
prove anything about the efficiency, which is quite amazing for
someone claiming to be so knowledgable and issuing challenges. To
measure anything meaningful regarding the heat pump efficiency, you
would have to measure not only the current going into the heat pump
but ALSO THE AMOUNT OF HEAT THE PUMP IS PUTTING INTO THE HOUSE AT THE
TWO DIFFERENT TEMPERATURES.

And if you did, you would find that for the same amount of electricity
consumed, you get a lot more heat from the pump when it's 50 outside
than you do when it's 25. The Dept of Energy says it works that way,
the HVAC company says it and I provided links. I could find you 20
other links that say it too. BTW Bubba, where's your link that says
it ain't so?

On Feb 13, 4:26*pm, "Hustlin' Hank" wrote:
On Feb 13, 8:01 am, Bubba wrote:



Hank,
Do me a favor. Go buy, rent or borrow an Amprobe. Its a cute little
device that simply clamps around an electric line and measures the
amount of amps running through a wire.
Put it on the wire going to your compressor (Common or Run) wire and
turn the heat pump on when it is, lets say around 55 degrees outside.
Now, try it another day when it is maybe 20 degrees outside.
Come back when you can intelligently explain to me why the amperage
reading is significantly lower when it is cold outside.
Bubba
Me really hates training the untrainable ones-

First: I don't have a heat pump in the house I am in now, so checking
the amps is impossible for me to do.

Second: I am not a HVAC installer, repairman, engineer or salesman.

Third: I have been a user of heat pumps and my impression as a "user"
is stated in one of my previous posts. I'll say it again, I don't like
them.

Fourth: I think we MAY be arguing apples and oranges and you mis-
understood (or I didn't explain it correctly) my original comments.

Fifth: ( Trying to explain my point again, altho most understood) I
was saying the word "efficiency" and maybe I should have said
"effectiveness" in regards to COST.

Sixth: You cannot convince me that a heat pump can save me money below
35 degrees in Ohio. I am up the road from you in Columbus, so I know
the weather.

Seventh: I appogize for *any mis-understanding on my part.

Eighth: I got nuthin' for 8.

Hank

Hank
One thought from a disaster preparedness perspective. depending on
which of the Rinnai direct vent gas heaters was installed they may run
without any electricity at all. So if you do buy the house don't be
too quick to remove those individual direct vent heaters even if you
do put in oil or propane fired heat. They not only allow you to run
the whole house cooler and just warm up the spaces you happen to be
using but they also make a great source of emergency heat following a
blizzard or ice storm induced large area power outage. The Rainnai
folks used to make a kit that allowed you to install one of their
heaters through a double hung window. If you live in an area that
gets deadly cold and you have elderly folks or small children in the
family that makes an excellent emergency heat source, albeit a rather
pricey one. Small children, the elderly, and anyone with a
respiratory impairment should not be exposed to the fumes from
unvented combustion heaters. Even the super improved newer models are
too hard on such folks.

I'm a firefighter by avocation and the fire chief assigned me to the
communities Emergency Preparedness Committee so I've had to study up
on these issues. We invest a lot of effort in trying to provide the
public with the information that they need to get by at home during
emergencies. The operation of special needs shelters is a major
challenge to disaster response resources. Hospital Emergency
Departments are not a good substitute for special needs shelters. The
type of emergency heat that people use has a major effect on how many
runs the ambulance is going to make while chained up. Dumping the
brittle patients in the Hospital Emergency Department because they
can't tolerate the emergency heater that their family is using does
not make friends of the ED staff that we will still have to live with
on a daily basis after the power comes back on.

--
Tom Horne

On Feb 12, 2:32*pm, Eric in North TX wrote:
On Feb 12, 1:08*pm, wrote:



On Feb 12, 1:16*pm, wrote:

Now, who should know more about energy and efficiency? * The DOE or
Bubba?- Hide quoted text -

- Show quoted text -

efficiency and effectiveness are NOT the same thing...

My heat pump is not very EFFECTIVE below 32 becasue it does not keep
my house comforatbale but it is still pretty EFFICIENT. * *Below 32,
the BTU that it puts out drops but so does the electric power that it
pulls.

Below 32, I switch off the heat pump and use oil.

Mark

I would have to disagree that the lower the temperature the less
electricity a heat pump will use. * The efficiency of a heat pump DOES
decline almopst linearly with decreasing temperature. * In other
words, for every KWH of electricity you put in it, you get more heat
out at 45F than you do at 25F. * If it were not so, then you could
just put in larger capacity heat pumps and cost effectively heat homes
where it was regularly 0 degrees, no?

I don't know about cost effective, but I oversize my PTAC units & get
heat hopefully at lower temperatures.
I upgraded both of my units mainly because the newer ones were higher
seer ratings. I also bought bigger units, somewhat oversize for the
area,
Both the upstairs and downstairs units seem to keep up nicely both hot
and cool they dehumidify on AC so I guess I didn't go too far.
I have no alternate in that part of the house, the gas furnace is
ducted there,
and I guess that was the original plan, but the ducts are just too
long to be effective, so I blocked them off.
There is a natural convection from the original one story to the 2
story, but it isn't enough for comfort

You apparently "did not go too far" as you said but, for the sake of
the uninitiated, let me point out that going too far, when up-sizing a
heat pump, isn't hard to do. I have encountered some installations
that actually were running so cold when cooling that they had
condensate dripping from the vent grills. In northern climates like
the Boston, Massachusetts area you are very close to the edge on the
original installation were the size is pushed upward to meet heating
requirements. Such heat pumps are more expensive to operate as
cooling systems because they do not dehumidify as well; note I did not
say at all: and so they have to be set lower to feel as cool as a unit
that dehumidifies more efficiently.

--
Tom Horne

On Feb 13, 7:12�pm, Tom Horne wrote:


Hank
One thought from a disaster preparedness perspective. �depending on
which of the Rinnai direct vent gas heaters was installed they may run
without any electricity at all. �So if you do buy the house don't be
too quick to remove those individual direct vent heaters even if you
do put in oil or propane fired heat. �They not only allow you to run
the whole house cooler and just warm up the spaces you happen to be
using but they also make a great source of emergency heat following a
blizzard or ice storm induced large area power outage. �The Rainnai
folks used to make a kit that allowed you to install one of their
heaters through a double hung window. �If you live in an area that
gets deadly cold and you have elderly folks or small children in the
family that makes an excellent emergency heat source, albeit a rather
pricey one. �Small children, the elderly, and anyone with a
respiratory impairment should not be exposed to the fumes from
unvented combustion heaters. �Even the super improved newer models are
too hard on such folks.

I'm a firefighter by avocation and the fire chief assigned me to the
communities Emergency Preparedness Committee so I've had to study up
on these issues. �We invest a lot of effort in trying to provide the
public with the information that they need to get by at home during
emergencies. �The operation of special needs shelters is a major
challenge to disaster response resources. Hospital Emergency
Departments are not a good substitute for special needs shelters. �The
type of emergency heat that people use has a major effect on how many
runs the ambulance is going to make while chained up. �Dumping the
brittle patients in the Hospital Emergency Department because they
can't tolerate the emergency heater that their family is using does
not make friends of the ED staff that we will still have to live with
on a daily basis after the power comes back on.

--
Tom Horne-

Hi Tom,

I am not the one buying the house. That is another poster. I was just
voicing my opinion.


I am a retired Fire Lieutenant/Paramedic of 27 years. So I understand
what you're saying about dropping people off at the ED for them to
baby-sit. It is a no-win situation.

Good luck with your assignment, it will be a challenge for sure.

Hank

On Feb 13, 4:51�pm, Bubba wrote:

Yes a heat pump loses efficiency or loses the ability to produce as
many btus as the outside temp drops.
BUT, the compressor isnt working as hard as the temp drops thus as you
would see by watching the amps.

Correct me if I am wrong. We are talking an electric motor that is
hermetrically sealed and running a compressor....correct? Knowing
this, why woud it use any less electric (KWH's) when colder? Is it
because the wires are cooler and not losing any heat? Does the voltage
drop when the weather gets cooler? What is the reason?

On another note. Altho amps figure into the equation somewhere, my
electric bill is figured on KWH. Since KWH's are increased due to the
fact the Unit is running more often and longer, wouldn't that cost you
more, there making the heat pump less desirable/cost effective below
35 degrees?

Hank ~~~having trouble understanding Bubba's logic.....but didn't
call it "stupid Bull****" :-)

On Feb 13, 8:05*pm, Bubba wrote:

Ninth:

Even if you did what Bubba asked, he doesn't even realize it would not
prove anything about the efficiency, which is quite amazing for
someone claiming to be so knowledgable and issuing challenges. * * To
measure anything meaningful regarding the heat pump efficiency, you
would have to measure not only the current going into the heat pump
but ALSO THE AMOUNT OF HEAT THE PUMP IS PUTTING INTO THE HOUSE AT THE
TWO DIFFERENT TEMPERATURES.

And if you did, you would find that for the same amount of electricity
consumed, you get a lot more heat from the pump when it's 50 outside
than you do when it's 25. * The Dept of Energy says it works that way,
the HVAC company says it and I provided links. * * I could find you 20
other links that say it too. * BTW Bubba, where's your link that says
it ain't so?

Once again Trader.........all you do is read. You believe all the crap
you read. I dont need a link when I have the experiment right there in
front of me. I can perform all the tests in the world on it.


Following that logic, you'd deny that the earth revolves around the
sun too, because you haven't personally verified it. As for your
"experiments", we need look no further than what you told Hank to
do. You told him to just take an amp meter and measure the current
going into a heat pump system at 55 degrees and then 20 degrees. Of
course with even a rudimentary understanding of what's involved here,
you'd know that to measure the efficiency of the system, YOU'D HAVE TO
ALSO MEASURE THE HEAT BEING PUT INTO THE HOME. Then and only then,
would you see that the efficiency of a heat pump declines with outside
temp.

But, you don't have to perform the experiment. It's right in the
data sheets for heat pump systems. Let's take a look at a typical
Goodman unit at your two temps:

http://www.goodmanmfg.com/Portals/0/pdf/SS-GSH14.pdf
For the GSH140421A heat pump:

Outside Temp 55 20

MBh of heat 44.4 26.6
KW Elec 3.08 2.77
Coefficient of Performance 4.21 2.81


In other words, yes it uses 10% less electricity at 20 degrees than it
does at 55, but you also get 40% less heat out. In other words, THE
EFFICEINCY HAS DROPPED BY 33%. That is also directly stated in the
in the COP numbers above.


Which is why, at some point below about 30 deg, it become more
economical to use another fuel, like natural gas to supply the heat.
The exact temp depends on the cost of the two different fuels.
Which is why dual fuel system are sold using those two fuels. If it
were economical to use a heat pump at lower temps than gas, they
wouldn't need to use a gas furnace. They could just use a second
heat pump. Fairly simple.

Let's see what some others have to say on this subject:

Lennox
http://www.lennox.com/owners/faq.asp...stion=69#cat-0
Also, a heat pump can be an effective add-on option to use in
conjunction with an existing gas furnace. With this dual-fuel option,
the two systems share the heating load, but never function at the same
time. Each system operates when it is most cost effective. The heat
pump will be the primary heating and cooling system. However, when the
temperature drops below the heat pump's ability to operate as
efficiently as the gas furnace, the gas furnace will take over until
the temperature rises enough for the heat pump to operate more
efficiently.


From KCPL, an electric company that has no reason to say nat gas
becomes more efficient at lower temps:

Dual-Fuel Air Source Heat Pump Systems.
These systems pair a heat pump with a
gas or propane furnace to provide back-up
heating during extremely cold conditions.
Dual-fuel systems take advantage of the
efficiencies of both units. Heat pumps are
most efficient in moderately cold weather
down to about 30 degrees. Gas furnaces
reach optimum efficiency in extreme cold.
Working in tandem, the units take turns
operating only at the temperatures where
maximum efficiency is achieved. Many
dual-fuel systems allow you to select the
temperature at which the switching between
units takes place. Usually that’s when
outdoor temperatures are around 30 degrees.



From the TVA, a major electric supplier that has no reason to tell
anyone that gas is more efficient:

http://www.energyright.com/heatpump/dualfuel.htm
A dual-fuel heat pump is an electric heat pump and a gas furnace all
in one. In the Tennessee Valley, where temperatures are typically
above freezing and we enjoy some of the lowest electric rates in the
U.S., a heat pump is the most efficient way to heat your home. In
those few instances when the temperature drops below freezing, a gas
furnace provides heat more economically. By combining the two, you can
have the benefits of both systems.



http://www.residential.carrier.com/i...ybridheat.html
Here a graphic display of a hybrid system from Carrier. You can
slide the outside and temp and watch it switch from heat pump to nat
gas. They have the conversion taking place in the 40's, which I
think is too high in most cases, but you get the point. They also
state: "The Hybrid Heat system differs from a traditional split
system by replacing the air conditioner with a heat pump. Heat pumps
cool your home on hot days and provide efficient heating in MODERATE
CLIMATES. (emphasis mine)


http://www.shoreviewtech.com/hp_temp.aspx
And finally, here's an online calculator for dual fuel systems. You
can put in your cost of nat gas, your cost of electricity and
efficiencies of the heat pump and gas furnace. It will then tell you
at what outside temp HEATING WITH NAT GAS BECOMES MORE COST EFFECTIVE
than continuing to run the heat pump.

Using my numbers here in NJ it's around 32 degrees.



I guess that you believe/d everything that Clinton, Bush and now
Obhama are saying too, right? After all, what they all promise is true
because they said it so obviously you believe it, right trader?
You must live with a lot of disappointment believing everything you
read. Especially stuff from the DOE.

Don't compare politicians to credible sources based on science and
engineering. BTW, I can't help but notice you have no links that say
heat pump efficiency doesn't decrease with outside temp.



As a side note, I met with my Aprilaire rep today for breakfast. I
showed him your figures on the humidifier. It took him about 5 minutes
to stop laughing after seeing your 131% increase in humidification by
using hot water. He told me he would get with the EE's (oh ****, that
outta be fun) and get me something. I told him I'd prefer it in
writing. 2 emails from him so far but nothing showing any figures.
"Go figure"
Bubba- Hide quoted text -


Two things are interesting in the above:

1 - In another thread you went to great lengths to discredit Aprilaire
as being a credible source on the subject. You stated they would say
anything to sell units, even though obviously that is a non-sequitur.
Yet, now you want to try to use them?

2 - I find it curious a rep from Aprilaire would say he's going to get
EE's, ie Electrical Engineers to look at the humidifier issue.
Clearly, your first thought would be to ask a mechanical engineer,
which I'm sure AA has, or a chemical engineer as evaporation falls
into their discipline.

On Feb 14, 4:27*pm, Bubba wrote:
On Sat, 14 Feb 2009 09:19:40 -0800 (PST), wrote:
On Feb 13, 8:05*pm, Bubba wrote:

Ninth:

Even if you did what Bubba asked, he doesn't even realize it would not
prove anything about the efficiency, which is quite amazing for
someone claiming to be so knowledgable and issuing challenges. * * To
measure anything meaningful regarding the heat pump efficiency, you
would have to measure not only the current going into the heat pump
but ALSO THE AMOUNT OF HEAT THE PUMP IS PUTTING INTO THE HOUSE AT THE
TWO DIFFERENT TEMPERATURES.

And if you did, you would find that for the same amount of electricity
consumed, you get a lot more heat from the pump when it's 50 outside
than you do when it's 25. * The Dept of Energy says it works that way,
the HVAC company says it and I provided links. * * I could find you 20
other links that say it too. * BTW Bubba, where's your link that says
it ain't so?

Once again Trader.........all you do is read. You believe all the crap
you read. I dont need a link when I have the experiment right there in
front of me. I can perform all the tests in the world on it.

Following that logic, you'd deny that the earth revolves around the
sun too, because you haven't personally verified it. * As for your
"experiments", we need look no further than what you told Hank to
do. * You told him to just take an amp meter and measure the current
going into a heat pump system at 55 degrees and then 20 degrees. *Of
course with even a rudimentary understanding of what's involved here,
you'd know that to measure the efficiency of the system, YOU'D HAVE TO
ALSO MEASURE THE HEAT BEING PUT INTO THE HOME. * Then and only then,
would you see that the efficiency of a heat pump declines with outside
temp.

Your non simplicity amazes me trader. Never did I say a heat pumps
efficiency doesnt decline with a decrease in outdoor temperature. How
stupid are you?
My arguement is that a heat pumps efficiency doesnt just magically
stop and your preset "35 degrees". To say that is just totally wrong.

Hmmm, then way back when I posted this:


"Although air-source heat pumps can be used in nearly all parts of
the
United States, they do not generally perform well over extended
periods of sub-freezing temperatures. In regions with sub-freezing
winter temperatures, it may not be cost effective to meet all your
heating needs with a standard air-source heat pump."

or this:

"The piece you're missing here is that amount of heat that you get for
the amount
of electricity consumed declines as the temp differential between the
inside temp and the outside temp increases. In other words, heat
pumps become LESS EFFICIENT the lower the outside temp. Which is
exactly the point Hank was making when you called his post stupid BS.
"

Why didn't you just say "I agree, the efficiency declines", instead of
telling Hank he's stupid and to measure the amps going into his heat
pump at at 20 vs 55? As if just measuring the amps in without the
BTUs of heat out would prove exactly what?





But, you don't have to perform the experiment. * It's right in the
data sheets for heat pump systems. *Let's take a look at a typical
Goodman unit at your two temps:

http://www.goodmanmfg.com/Portals/0/pdf/SS-GSH14.pdf
For the GSH140421A heat pump:

Outside Temp * * * * * * * * * * * * *55 * * * * * * * * *20

MBh of heat * * * * * * * * * * * * * 44.4 * * * * * * * 26.6
KW Elec * * * * * * * * * * * * * * * * 3.08 * * * * * * *2.77
Coefficient of Performance * * * *4.21 * * * * * * *2.81

In other words, yes it uses 10% less electricity

Hmm, amazing. It uses less electricity as it gets colder. In case you
werent following along, That is EXACTLY what I said even though you
seem to have some unforseen ability to add meaning and words to my
phrases. You truely are magical, trader. Wiggle your nose for me.

at 20 degrees than it
does at 55, but you also get 40% less heat out. * In other words, THE
EFFICEINCY HAS DROPPED BY 33%. * That is also directly stated in the
in the COP numbers above.

Yep, the efficiency drops with the outdoor temperature.

Funny how we're hearing that now, after how many posts? But, it's a
start.



Once again,
nothing new there although you seem to see that there is. Admittidly,
I never mentioned 33%.

Probably because you denied the effect existed.






Which is why, at some point below about 30 deg,

Uh oh, there is that "about" word which is used when you dont know
what that exact number is. Just a little fact that might make you feel
better. Not many people can seem to come up with that exact number.
Amazing too that even in the instructions and performance charts with
units that they dont give you any charts as to where to set that
magical number. Does that maybe give you a clue that it is a number
that takes a large amount of time and formulas to come up with? No, I
didnt think that dawned on you trader. Many things like that seem to
pass right by your thick head.


It doesn't take large amount of time or formulas. It's based on the
efficiency of the heat pump at the given temperature, the efficiency
of the alternative system, eg natural gas furnace, and the costs of
the electricity and gas.



it become more
economical to use another fuel, like natural gas to supply the heat.
The exact temp depends on the cost of the two different fuels.

Hey, your just might be beginning to catch on now. Maybe there is hope
after all.

I've been saying exactly that since the beginning. In fact, that was
Hank's point to which you replied that he was stupid. Welcome to
reality.




Which is why dual fuel system are sold using those two fuels. * *If it
were economical to use a heat pump at lower temps than gas, they
wouldn't need to use a gas furnace. * They could just use a second
heat pump. * Fairly simple.

Again, you are close here but your 35 degree temp is too high. Heat
pumps do a very nice job even down to 15 degrees outside. Now just so
i dont wrinkle your thoughts too much, Im not talking about a 15 or 20
year old heat pump.

Funny how only Bubba says 15 or 20, while all the actual
manufacturers, energy companies, DOE, etc say more like in the 30's.
I guess we have our answer to why systems don't use another heat pump
to providde more heat at lower temps though. Answer: Because it isn't
economical compared to gas.



When heat pumps first came out they were a nice
thought but just not ready for prime time. I was in on the first batch
of Lennox heat pumps that were added to their electric furnace. You
had to add your own relays to make it happen. Then along came the
really cold weather and compressor after compressor was failing. Why?
Because their brilliant EE's didnt take into account that you couldnt
use a standard air conditioning compressor for near 0 outdoor temps.
Out comes a newer heat pump compressor and all is well again.



One more time, compressors are designed by mechanical engineers, not
EE's which are electrical engineers.




Let's see what some others have to say on this subject:

Lennox
http://www.lennox.com/owners/faq.asp...stion=69#cat-0
Also, a heat pump can be an effective add-on option to use in
conjunction with an existing gas furnace. With this dual-fuel option,
the two systems share the heating load, but never function at the same
time. Each system operates when it is most cost effective. The heat
pump will be the primary heating and cooling system. However, when the
temperature drops below the heat pump's ability to operate as
efficiently as the gas furnace, the gas furnace will take over until
the temperature rises enough for the heat pump to operate more
efficiently.

Notice no "magical" change over temperature stated in your above
paragraph. A least Lennox has a clue.



From KCPL, an electric company that has no reason to say nat gas
becomes more efficient at lower temps:

Dual-Fuel Air Source Heat Pump Systems.
These systems pair a heat pump with a
gas or propane furnace to provide back-up
heating during extremely cold conditions.
Dual-fuel systems take advantage of the
efficiencies of both units. Heat pumps are
most efficient in moderately cold weather
down to about 30 degrees.

And there is your favorite word again trader. The word "about 30
degrees".

Yes, and it's about 30, not your 15 or 20. You see many heat pump
systems in VT, MN?



For someone that seems to be such a stickler on exact words
a meaning, Im suprised that you would print that one. Dont worry
though, I would expect that from an electric company that has no
expertice in the field of heat pumps. Perhaps their gas market is more
profittable to them than electric? Opps. Maybe a variable that the Oh
mightyless trader forgot about.

No, didn't forget a thing. But you just proved yourself wrong again,
because KCPL sells electric, not gas. You could have prevented making
an ass of yourself again by just checking the basic facts. So, if
anything, KCPL has every motive to make heat pumps looks good. But
even they say heat pumps are only efficient vs other alternatives down
to about 30. Note 30, not 15 or 20





Gas furnaces
reach optimum efficiency in extreme cold.
Working in tandem, the units take turns
operating only at the temperatures where
maximum efficiency is achieved. Many
dual-fuel systems allow you to select the
temperature at which the switching between
units takes place. Usually that’s when
outdoor temperatures are around 30 degrees.

Uh huh. Nite exactly the word "about" this time but now they use
"around". That is just so exact and scientific trader. Nice job.

Again, about 30. Not 15 or 20. Where are your links?




From the TVA, a major electric supplier that has no reason to tell
anyone that gas is more efficient:

http://www.energyright.com/heatpump/dualfuel.htm
A dual-fuel heat pump is an electric heat pump and a gas furnace all
in one. In the Tennessee Valley, where temperatures are typically
above freezing and we enjoy some of the lowest electric rates in the
U.S., a heat pump is the most efficient way to heat your home. In
those few instances when the temperature drops below freezing, a gas
furnace provides heat more economically. By combining the two, you can
have the benefits of both systems.

I can see why this one would confuse you. I would like to see their
study where they seem to think that you automatically turn a heat pump
off at 32 degrees.


We'd all like to see your study or links that say heat pumps are cost
efficient compared to gas at 15 F.





http://www.residential.carrier.com/i...ybridheat.html
Here a graphic display of a hybrid system from Carrier. * You can
slide the outside and temp and watch it switch from heat pump to nat
gas. * They have the conversion taking place in the 40's, which I
think is too high in most cases, but you get the point. * They also
state: *"The Hybrid Heat system differs from a traditional split
system by replacing the air conditioner with a heat pump. *Heat pumps
cool your home on hot days and provide efficient heating in MODERATE
CLIMATES. *(emphasis mine)

(slide the outside and temp)?? Who wrote that........a 12 yr old?
Converting over to gas at somewhere above 40? Even you know that is
incorrect trader which sheds even more light onto the effect that if
this was written by Carrier (and Im sure it wasnt) then thats pretty
sad

It's on Carrier's website, which speaks for itself. By the way
Bubba, lots of HVAC companies have websites, chock full of info.
Where's yours?



and You trader think you know even better than Carrier with your
magical 35 number? Shame on you for being so thinkingly bold.

http://www.shoreviewtech.com/hp_temp.aspx
And finally, here's an online calculator for dual fuel systems. *You
can put in your cost of nat gas, your cost of electricity and
efficiencies of the heat pump and gas furnace. * It will then tell you
at what outside temp HEATING WITH NAT GAS BECOMES MORE COST EFFECTIVE
than continuing to run the heat pump.

Using my numbers here in NJ it's around 32 degrees.

Which then tells me nothing more than the fact that your electricity
rates in NJ are high.

And what do you think they are in Boston, which where the OP is
located? Even higher. Yet, Hank was supposed to be stupid because
he said the cross over point, where gas becomes more cost effective is
around 35. Every reference I've given you, and it's a lot now,
consistently are around that temp. I can't find one that says it's
at 15F. Please provide a link.



It also shows me that you have no idea how to calculate it because it
takes a TON more information to come up with an accurate temperature
at which you changeover your heat pump to some fossil fuel.
You need to have a proper Load calculation done on your home (no, you
cant use those cheap free ones you find on the internet trader). Dont
get cheap on me now. You also ...



And your reference for that would be? Does DOE say it depends on a
load calc? HVAC company? Lennox? Who besides Bubba? We know the
efficiency of a gas furnace. You put X amount of gas in, you get Y
BTU's of heat out. We know the efficiency of a heat pump at various
temps, it's in the data sheet. You put X KW in, you get Y BTUs
out. I even gave you a website with the calculator where you can
enter the above information and it shows a crossover in the 30's, not
at 15.

Show us a link to a website that says a heat pump is cost effective vs
gas at 15F.

On Feb 15, 9:59*am, Bubba wrote:
On Sat, 14 Feb 2009 17:01:24 -0800 (PST), wrote:
On Feb 14, 4:27*pm, Bubba wrote:
On Sat, 14 Feb 2009 09:19:40 -0800 (PST), wrote:
On Feb 13, 8:05*pm, Bubba wrote:

Ninth:

Even if you did what Bubba asked, he doesn't even realize it would not
prove anything about the efficiency, which is quite amazing for
someone claiming to be so knowledgable and issuing challenges. * * To
measure anything meaningful regarding the heat pump efficiency, you
would have to measure not only the current going into the heat pump
but ALSO THE AMOUNT OF HEAT THE PUMP IS PUTTING INTO THE HOUSE AT THE
TWO DIFFERENT TEMPERATURES.

And if you did, you would find that for the same amount of electricity
consumed, you get a lot more heat from the pump when it's 50 outside
than you do when it's 25. * The Dept of Energy says it works that way,
the HVAC company says it and I provided links. * * I could find you 20
other links that say it too. * BTW Bubba, where's your link that says
it ain't so?

Once again Trader.........all you do is read. You believe all the crap
you read. I dont need a link when I have the experiment right there in
front of me. I can perform all the tests in the world on it.

Following that logic, you'd deny that the earth revolves around the
sun too, because you haven't personally verified it. * As for your
"experiments", we need look no further than what you told Hank to
do. * You told him to just take an amp meter and measure the current
going into a heat pump system at 55 degrees and then 20 degrees. *Of
course with even a rudimentary understanding of what's involved here,
you'd know that to measure the efficiency of the system, YOU'D HAVE TO
ALSO MEASURE THE HEAT BEING PUT INTO THE HOME. * Then and only then,
would you see that the efficiency of a heat pump declines with outside
temp.

Your non simplicity amazes me trader. Never did I say a heat pumps
efficiency doesnt decline with a decrease in outdoor temperature. How
stupid are you?
My arguement is that a heat pumps efficiency doesnt just magically
stop and your preset "35 degrees". To say that is just totally wrong.

Hmmm, then way back when I posted this:

"Although air-source heat pumps can be used in nearly all parts of
the
United States, they do not generally perform well over extended
periods of sub-freezing temperatures. In regions with sub-freezing
winter temperatures, it may not be cost effective to meet all your
heating needs with a standard air-source heat pump."

or this:

"The piece you're missing here is that amount of heat that you get for
the amount
of electricity consumed declines as the temp differential between the
inside temp and the outside temp increases. *In other words, heat
pumps become LESS EFFICIENT the lower the outside temp. * Which is
exactly the point Hank was making when you called his post stupid BS.
"

Why didn't you just say "I agree, the efficiency declines", instead of
telling Hank he's stupid and to measure the amps going into his heat
pump at at 20 vs 55? * As if just measuring the amps in without the
BTUs of heat out would prove exactly what?

Because you and Hank state that 35 is the magic heat pump cut-off
temperature. You and he are both wrong on that point.




Never stated any such thing. Only stated that at about that temp the
efficiency of heat pumps drops so that other fuels, like gas can
become more cost effective. Which BTW, are the 2 fuel choices in the
original post from Boston.





It doesn't take large amount of time or formulas. * It's based on the
efficiency of the heat pump at the given temperature, the efficiency
of the alternative system, eg natural gas furnace, and the costs of
the electricity and gas.

Oh, so now you think the rate at which a home losses its heat to the
outdoors has nothing to do with when the heat pump should shut off and
a fossil fuel should take over?
You are a classic trader. Sometimes you just dont have the first clue.



Once again Bubba, your lack of any grounding in science has you
confusing two different things:

1 - With a heat pump, as the efficiency declines with outside temp,
there is a temp point at which other fuels like nat gas become MORE
COST EFFECTIVE. This doesn't depend on the heat loss of the house,
the number of windows or anything else. It depends on the efficiency
of the heat pump at a particular temp, the efficiency of the
alternative gas furnace, the cost of electricity, and the cost of
gas. You could have the windows wide open and all the heat going
out. The only question here is to generate X BTU's with a given
outside temp, which is more cost effective, running the heat pump or
running a gas furnace.

2 - With a heat pump, as the efficiency declines with outside temp and
the total heat output drops too, there is a temp point at which the
heat pump can no longer supply enough heat to keep the house at the
desired temp. It then requires additonal heat from some other source,
again it could be gas, per this example. The temp at which this
occurs, does depend on the heat loss of the house.

#1 Above involves efficiency, ie which fuel will heat the house most
economically. You want to switch at that temp to save money.

#2 just involves getting enough heat, withour regard to efficiency.
You have to switch at that point to keep the house at the desired
temp. In fact, if the alternate fuel is resistance electric heat, #2
will make the cost of heating increase substantially, not decrease.




it become more
economical to use another fuel, like natural gas to supply the heat.
The exact temp depends on the cost of the two different fuels.

Hey, your just might be beginning to catch on now. Maybe there is hope
after all.

I've been saying exactly that since the beginning. *In fact, that was
Hank's point to which you replied that he was stupid. *Welcome to
reality.

Making up more lies, trader? Once again, it was the temp statement.
And I still say you are STUPID if you think it makes sense to turn a
heat pump off at 35 degrees. Period!



Provided you with plenty of links that say the point where heat pumps
lose effiency so that gas becomes more cost effective is around that
point: Dept of Energy, KCPL, Tenn Valley Authority, Carrier. Even
gave you a link to an online calculator,

http://www.shoreviewtech.com/hp_temp.aspx

which allows you to input the costs of the fuels, efficiency of the
heat pump, gas furnace and determine it yourself. For my fuel costs
here in NJ, it is 32 deg.

And you just choose to dismiss it all. We're still waiting for your
link that says a heat pump is effective vs gas down to 15. Funny how
you have NO links.









Which is why dual fuel system are sold using those two fuels. * *If it
were economical to use a heat pump at lower temps than gas, they
wouldn't need to use a gas furnace. * They could just use a second
heat pump. * Fairly simple.

Again, you are close here but your 35 degree temp is too high. Heat
pumps do a very nice job even down to 15 degrees outside. Now just so
i dont wrinkle your thoughts too much, Im not talking about a 15 or 20
year old heat pump.

Funny how only Bubba says 15 or 20, while all the actual
manufacturers, energy companies, DOE, etc say more like in the 30's.
I guess we have our answer to why systems don't use another heat pump
to providde more heat at lower temps though. *Answer: Because it isn't
economical compared to gas.

No, because its not economical to purchase two systems or more.

Why not? You're purchasing two anyway. Either a heat pump AND a
gas furnace. Or a heat pump and another heat pump. Could certainly
just as easily put two heat pumps in one packaged system. Obvious
answer: because heat pumps just aren't efficient enough at lower
temps to make it worthwhile.



Then,
like I explained before, If you had enough heat output to warm your
home at 0 degrees outside your cooling capacity would be more than 2
or 3 times what you need in the summer.



Why? You can turn off the gas furnace, but can't turn off a second
heat pump?




When heat pumps first came out they were a nice
thought but just not ready for prime time. I was in on the first batch
of Lennox heat pumps that were added to their electric furnace. You
had to add your own relays to make it happen. Then along came the
really cold weather and compressor after compressor was failing. Why?
Because their brilliant EE's didnt take into account that you couldnt
use a standard air conditioning compressor for near 0 outdoor temps.
Out comes a newer heat pump compressor and all is well again.

One more time, compressors are designed by mechanical engineers, not
EE's which are electrical engineers.

Funny how you like to nit pick at words. Does it make you feel
inferior when I pick at EE's like you? Must be a reason you feel that
way? Must be a reason so many people pick at EE's like you?



No, I just think when you keep refering to electrical engineers when
talking about compressors and humdifiers, it shows how totally
clueless you really are. Kind of like when you told Hank to just
measure the amps going into his compressor as the temp drops.
Everyone else here realizes that without also measuring the heat
output into the house, it's meaningless.