I think I understand why new furnaces are more efficient, but why AC?

I finally read an explanation about the exhaust air being cooler, as
low as 90 degrees F from gas furnaces, and more heat extracted from
the fire to heat the house, in new furnaces. I presume new oil
furnaces are more efficient the same way.

But why are new AC's more efficient. There is no cold air going up
the chimney with an old AC. I presume that if the refrigerant doesn't
lose all its coldth, warm up to room temperature, in the AC evaporator
inside the main air duct, when it returns to the condensor, it's that
much easier to condense because it is colder, and less heat has to be
radiated out from the condensor fins. So iiuc there is no loss there,
at least if that pipe is insulated.

So why are the new ACs more efficient?

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

So why are the new ACs more efficient?

Not a single clue, here.

By next January R22 (?) is illegal?

I'm being bombarded with these "energy credit" savings ads for a new
HVAC unit.

My unit is 12 years old...

It might work in may case?

On Thu, 05 Nov 2009 17:57:37 -0800, Oren wrote:

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

So why are the new ACs more efficient?

Not a single clue, here.

By next January R22 (?) is illegal?

I'm being bombarded with these "energy credit" savings ads for a new
HVAC unit.

My unit is 12 years old...

It might work in may case?

They'll sell you anything. It doesn't mean you need it. But I have
no idea.

mm wrote:
....
But why are new AC's more efficient. ...

Because they use better more efficient compressors, etc., to be able to
produce more useful work from the same input energy.

That's what engineers are for...

--

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

I think I understand why new furnaces are more efficient, but why AC?

Technically, I don't know. But window ACs, and even refrigerators,
are a lot more efficient now, too. Could just be the insulation on
the fridge, but just better engineering of blowers and fins and stuff
can help, too. Just electric motors that don't surge but have
electronics driving them, I think, maybe venting motor heat outside
instead of inside, etc.

J.

On Thu, 05 Nov 2009 18:12:41 -0800, JRStern
wrote:

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

I think I understand why new furnaces are more efficient, but why AC?

Technically, I don't know.

Great answer.

But window ACs, and even refrigerators,
are a lot more efficient now, too. Could just be the insulation on
the fridge, but just better engineering of blowers and fins and stuff
can help, too. Just electric motors that don't surge but have
electronics driving them, I think, maybe venting motor heat outside
instead of inside, etc.

Also good.

J.

On Thu, 05 Nov 2009 18:12:41 -0800, JRStern
wrote:

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

I think I understand why new furnaces are more efficient, but why AC?

Technically, I don't know. But window ACs, and even refrigerators,...

J.

And thanks, all.

The first thing about newer high efficiency a/c is the coil size-- both
condenser and evaporator. A new 2 ton unit is physically larger than
most 5 ton units of yesteryear. Scroll compressors (that most but not
all use) are somewhat more efficient than recips. The condenser coils
themselves, as well the whole condenser fan assembly are designed-- with
computer aid, not available years ago-- to get the optimum airflow with
much lower horsepower fan motors than old units, as are the evaporators
also.. All the motors-- condenser fan, blower, and compressor, have been
"tweaked' to maximum efficiency. Most all higher SEER units use
expansion valves instead of fixed orifice or capillay tube refrigerant
flow control. A few 13 SEER units use flowrator (fixed orifice) , but
pretty much all above 13 are TXV. Most all 16 + SEER units are two
stage, some even having two compressors. Just as with fuel mileage on
cars, the manufacurers have gotten all the easy gains in efficiency they
are going to get. Barring some breakthrough invention, future efficiency
gains will be small and costly. HTH Larry

On Nov 6, 1:31*am, wrote:

In spite of all of this new freon in the world. the ozone hole that
everyone had their panties in a wad over, shrunk.
..
Because the better organized and more responsible countries of the
world took measures to reduce the release of the older style
refrigerants into the atmosphere and/or legislated the use of less
polluting (although possibly less effective?) ones for new
production.

It does kinda prove two things, a) Humans activity can/does affect the
planets environment. b) Measures can be taken to change activities
that pollute. Somewhat encouraging actually if our politicians would
stop squabbling and pointing at each other and actually act instead of
worrying where their next campaign contribution will come from!

In Canada, for example, those in the refrigeration industry and
maintenance business have operated under some very strict measures.
But have visited gulf countries in the Middle East where, along with a
booming economy based almost entirely on the production of oil and
gas, there were few if any refrigeration controls. R22 could be bought
over the counter and anyone working on auto and home AC units,
considered almost essential on most vehicles and in all living units
over there, would routinely just purge refrigerant into the
atmosphere!

The situation is much the same as when the Europeans (particularly
Britain) with industrial economies based on several hundred years of
the use of coal finally decided that the health problems, disruption
of travel and the corrosion and other deterioration caused by acid
rain and smog were too high. Today, in the London UK area for example
the use of coal has been just about banned for many past years.

In other words 'good-responsible' government. Just look at the mess
irresponsible (weak) governemnt has done in the financial-banking
industry!

On Thu, 5 Nov 2009 23:08:02 -0800 (PST), terry
wrote:

On Nov 6, 1:31*am, wrote:

In spite of all of this new freon in the world. the ozone hole that
everyone had their panties in a wad over, shrunk.

But this wasn't (just?) blamed on freon as I recall it. It was
chloro-fluoro-carbons, which were just about eliminated from use years
ago, weren't they, certainly in the high-consuming countries if not
everywhere.
.
Because the better organized and more responsible countries of the
world took measures to reduce the release of the older style
refrigerants into the atmosphere and/or legislated the use of less
polluting (although possibly less effective?) ones for new
production.

It does kinda prove two things, a) Humans activity can/does affect the
planets environment. b) Measures can be taken to change activities
that pollute. Somewhat encouraging actually if our politicians would
stop squabbling and pointing at each other and actually act instead of
worrying where their next campaign contribution will come from!

In Canada, for example, those in the refrigeration industry and
maintenance business have operated under some very strict measures.
But have visited gulf countries in the Middle East where, along with a
booming economy based almost entirely on the production of oil and
gas, there were few if any refrigeration controls. R22 could be bought
over the counter and anyone working on auto and home AC units,
considered almost essential on most vehicles and in all living units
over there, would routinely just purge refrigerant into the
atmosphere!

The situation is much the same as when the Europeans (particularly
Britain) with industrial economies based on several hundred years of
the use of coal finally decided that the health problems, disruption
of travel and the corrosion and other deterioration caused by acid
rain and smog were too high. Today, in the London UK area for example
the use of coal has been just about banned for many past years.

In other words 'good-responsible' government. Just look at the mess
irresponsible (weak) governemnt has done in the financial-banking
industry!

And Lake Erie or large parts of it had little or no life in it until
steps were taken. I think there is also fishing around Manhattan
Island now, that was not possible a few years ago.

I don't mean Mr. Fretwell, but it seems to be a matter of religious
faith almost that the earth can't be ruined by people, and yet we've
seen parts of it get ruined. I don't see why they are sure the whole
earth couldn't be.

On Nov 5, 7:40*pm, mm wrote:
I think I understand why new furnaces are more efficient, but why AC?

I finally read an explanation about the exhaust air being cooler, as
low as 90 degrees F from gas furnaces, and more heat extracted from
the fire to heat the house, in new furnaces. *I presume new oil
furnaces are more efficient the same way.

But why are new AC's more efficient. * There is no cold air going up
the chimney with an old AC. *I presume that if the refrigerant doesn't
lose all its coldth, warm up to room temperature, in the AC evaporator
inside the main air duct, when it returns to the condensor, it's that
much easier to condense because it is colder, and less heat has to be
radiated out from the condensor fins. *So iiuc there is no loss there,
at least if that pipe is insulated.

So why are the new ACs more efficient?

The same reason new refrigerators can be 75% more efficent than units
30 yrs old, they were designed with efficency, not profit, as a goal.
www.energystar.gov

mm wrote:
On Thu, 05 Nov 2009 18:12:41 -0800, JRStern
wrote:

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

I think I understand why new furnaces are more efficient, but why AC?
Technically, I don't know. But window ACs, and even refrigerators,...

J.

And thanks, all.

Some good answers. I don't know the technicality but when I got a new
AC a few years ago, my summer electric bill was halved.

wrote in message ...
In spite of all of this new freon in the world. the ozone hole that
everyone had their panties in a wad over, shrunk.

Ozone holes aren't caused by "Freon in the world", they're caused by Freon (CFCs if you're
trademark-averse) in the atmosphere.

China / India / whoever go berserk making new A/C's, the Freon stays inside them, everything's fine.
*Until* it gets let out... by the A/C developing a leak or intentional release. Then the fun
starts... 10, 15, 20 years from now.

Eric Law

"mm" wrote in message ...
I don't mean Mr. Fretwell, but it seems to be a matter of religious
faith almost that the earth can't be ruined by people, and yet we've
seen parts of it get ruined. I don't see why they are sure the whole
earth couldn't be.

Because it could mean they have to make some sort of personal sacrifice or endure some kind of
hardship. Denial requires much less effort!

Eric Law

On Fri, 6 Nov 2009 04:11:44 -0800 (PST), ransley
wrote:

The same reason new refrigerators can be 75% more efficent than units
30 yrs old, they were designed with efficency, not profit, as a goal.

I think the new ones are profitable for the manufacturers, too.

I assume more expensive too - with energy prices up, the math just
says it's worth spending a few more bucks up front to save energy for
X years. Times change, optimal design decisions change.

And there is simply better tech, better insulating materials, better
thermostats, better electronic motor controls, more precise machining
of compressor parts, better engineering of airflow within, etc. Just
making some of the heat exchanger elements 5% larger can increase
efficiency, it doesn't have to be rocket science.

J.

On Fri, 6 Nov 2009 07:49:02 -0500, "Eric" wrote:


wrote in message ...
In spite of all of this new freon in the world. the ozone hole that
everyone had their panties in a wad over, shrunk.

Ozone holes aren't caused by "Freon in the world", they're caused by Freon (CFCs if you're
trademark-averse) in the atmosphere.

So Freon is a CFC. Oops. I checked and you're right. That makes my
answer to Terry, whicch included an answer to gfretwell, pretty
stupid.

China / India / whoever go berserk making new A/C's, the Freon stays inside them, everything's fine.
*Until* it gets let out... by the A/C developing a leak or intentional release. Then the fun
starts... 10, 15, 20 years from now.

Eric Law

On Fri, 06 Nov 2009 07:22:16 -0500, Frank
wrote:

mm wrote:
On Thu, 05 Nov 2009 18:12:41 -0800, JRStern
wrote:

On Thu, 05 Nov 2009 20:40:08 -0500, mm
wrote:

I think I understand why new furnaces are more efficient, but why AC?
Technically, I don't know. But window ACs, and even refrigerators,...

J.

And thanks, all.

Some good answers. I don't know the technicality but when I got a new
AC a few years ago, my summer electric bill was halved.

Thanks.

wrote in message ...
On Fri, 6 Nov 2009 07:49:02 -0500, "Eric" wrote:
The chinese have been "going berserk" making the billion R12
refrigerators they promised in the 70s. Are you saying every one of
them still has all the original refrigerant in them?
That still ignores the fact that all freon gets vented eventually. As
careful as you may be, the main reason most appliances get thrown away
is the freon is gone.
I'm not sure about that, although I'd agree it often escapes eventually. Especially in the case of
car A/Cs, where leakage is just about guaranteed as the car ages.

On the other hand, when I was a kid I used to enjoy bringing window A/Cs home from the dump and
seeing if I could make them work. Of those, I'd say maybe 1/3 had random electrical problems that
were easily fixed, and almost all the remainder had seized compressors or fans (or both). Think I
only ever saw one where the refrigerant had escaped.

I also question how well we recycle. I know the fridge and the package
AC unit I had the county haul away were vented in the street in front
of my house ... after I heard all about the "special pickup" and how
they had to do something special with the freon. They just grabbed the
package unit with a claw truck and banged it in the bed until the
freon blew out, then drove away. The guys cut the copper out of the
fridge.

That's really sad. I always suspected that happened some of the time, but I'd never heard a
firsthand account before.

Eric Law

"mm" wrote in message
...
I think I understand why new furnaces are more efficient, but why AC?

I finally read an explanation about the exhaust air being cooler, as
low as 90 degrees F from gas furnaces, and more heat extracted from
the fire to heat the house, in new furnaces. I presume new oil
furnaces are more efficient the same way.

But why are new AC's more efficient. There is no cold air going up
the chimney with an old AC. I presume that if the refrigerant doesn't
lose all its coldth, warm up to room temperature, in the AC evaporator
inside the main air duct, when it returns to the condensor, it's that
much easier to condense because it is colder, and less heat has to be
radiated out from the condensor fins. So iiuc there is no loss there,
at least if that pipe is insulated.

So why are the new ACs more efficient?

Ummm.... maybe to save you operating costs? A new unit could save you a
substantial amount on your electric bill over a 10-15 year old one.

"mm" wrote in message
I think I understand why new furnaces are more efficient, but why AC?


It is mostly in the electric motors which are used for the compressor and
fans.

Actually house electricity is not very "efficient" for running an electric
motor. So what they do is make their "own electricity" to run the electric
motors. Then design the most efficient electricity/motor pair.

For example electric motors run more efficiently on 3 phase electricity,
they may convert the house electricity to a form of 3 phase electricity for
the electric motors.

Or they can control the "speed" of the electric motors. Rather than on full
blast or off, they can run these are various speeds. If just a little
cooling is needed, slower speeds will do the job.

They basically put their thinking caps on and come up with ANYTHING which
will save a bit of energy. With modern electronics and computer control, all
sorts of things are now possible...

Here is one which says...
"Daikin's Reluctance DC motors utilize powerful neodymium magnets that are
10 times more powerful than conventional magnets. By maximizing torque,
Daikin's reluctance DC motors can boost efficiencies 20% higher than
conventional motors."
http://www.energysuperstore.com.au/3...Split_Systems/

This one says...
"Regular A/C units have a compressor that switches on whenever the room gets
too warm and runs at full power until the room is cool enough, then shuts
off. The inverter makes it possible to run the compressor continually at a
lower power to maintain the room temperature eliminating the frequent
stopping and starting required by standard systems ."
http://harborpointac.com/wall-split-...c/prod_14.html

On "Variable Frequency Drives"...
http://oee.nrcan.gc.ca/publications/...1e.cfm?attr=20

Variable Frequency Drive Technology Can Save Over 30% In Energy Costs...
http://www.maintenanceresources.com/...drives/vfd.htm

On Fri, 6 Nov 2009 00:12:08 -0600, (Lp1331 1p1331)
wrote:

The first thing about newer high efficiency a/c is the coil size-- both
condenser and evaporator. A new 2 ton unit is physically larger than
most 5 ton units of yesteryear. Scroll compressors (that most but not
all use) are somewhat more efficient than recips. The condenser coils
themselves, as well the whole condenser fan assembly are designed-- with
computer aid, not available years ago-- to get the optimum airflow with
much lower horsepower fan motors than old units, as are the evaporators
also.. All the motors-- condenser fan, blower, and compressor, have been
"tweaked' to maximum efficiency. Most all higher SEER units use
expansion valves instead of fixed orifice or capillay tube refrigerant
flow control. A few 13 SEER units use flowrator (fixed orifice) , but
pretty much all above 13 are TXV. Most all 16 + SEER units are two
stage, some even having two compressors. Just as with fuel mileage on
cars, the manufacurers have gotten all the easy gains in efficiency they
are going to get. Barring some breakthrough invention, future efficiency
gains will be small and costly. HTH Larry

Thanks and thanks to all of you.

Dear Eric:

On Nov 6, 5:49*am, "Eric" wrote:
wrote in messagenews:2797f5la8j3kpi9iek4e9q3fsi7s6sa7am@4ax .com...
In spite of all of this new freon in the world. the
ozone hole that everyone had their panties in a
wad over, shrunk.

Ozone holes aren't caused by "Freon in the world",
they're caused by Freon (CFCs if you're
trademark-averse) in the atmosphere.

The ozone hole is a natural, recurring event. The size of the hole,
the date of start, the duration, and the minimum ozone value
obtained... are a function of the contaminants in the "ozone layer".
This includes chlorine- and bromine-containing compounds, as well as
water vapor.

China / India / whoever go berserk making new
A/C's, the Freon stays inside them, everything's fine.
*Until* it gets let out... by the A/C developing a leak
or intentional release. *Then the fun starts... 10, 15,
20 years from now.

The fluorocarbons are next. We keep making inert compounds that can
only leave our biosphere via the (nearly the) same energetic radiation
that makes ozone. All because without the chlorine, bromine, or
flourine there, they are too flammable for safety.

David A. Smith