I am in the process of adding central air to an existing furnace
system. The system currently includes a Honeywell electronic air
cleaner made in 1976. As part of the addition, I am considering
replacing the old Honeywell with an Envirosept Electronic Furnace
Filter, which sounds pretty good just from browsing the Net.


My question is, would this new unit be much more effective (or less
effective) than the old one? I know the old one is working to some
extent, since I can see the dirt come off when it gets cleaned.


Any advice greatly appreciated!

Media air filters typically filter the air better than standard
fiberglass filters. However they have much more resistance to air flow
than standard air filters. Typically, they reduce measured overall air
flow by 10% to 20%. If you add an AC coil to your existing furnace,
you will be reducing air flow some with it. The electronic air filters
usually have low resistance to air flow, I would stick with the
existing electronic filter. Electronic filters are usually more
effiient than media filters as well.

Remember: Air Conditioning begins with AIR!

Stretch

wrote:

...I am considering replacing the old Honeywell with an Envirosept
Electronic Furnace Filter, which sounds pretty good...

Aqua Air Technologies, Inc. 3137 Cabin Run, Woodbine, MD 21797
800-854-5126 Fax: 800-489-4186
http://envirosept.com/aircleaners.html

Seems very good to me.

Nick

Stretch wrote:

Electronic filters are usually more effiient than media filters as well.

This charged media filter is more efficient...

Typical Ambient Particle
Size distribution (in microns) per m^3 Particle Removal Rates

% by % by Electrostatic Envirosept
Size (um.) Count count weight ($800-1200) ($200)

10+ 1,000 .005% 28% xxx x 99% 99+%
5-10 35,000 .175% 52% x x 95% 99+%
1-5 264,000 1.32% 17% x x 85% 99+%
..5-1 1,352,000 6.78% 2% xxx 60% 90+%
..01-.5 18,280,000 91.72% 1% xxx 40% 65%

|||||_ bacteria/viruses/spores
||||_ cooking/tobacco smoke
|||_ household dust
||_ pollen/mold/spores
|_ dander/hair

Average synthetic dust weight arrestance: 79%

Single pass efficiency: 33% @0.3 um, 75% @0.5 um, 95% @1 um, 99% @3 um

Pressure drop: 0.05" @150 lfm, 0.1" @225 lfm, 0.15" @300 lfm, 0.22" @375 lfm

ASHRAE dust holding capacity: 20 gm/ft^2

Does not produce ozone

Nick

Nick,

From what I understand from their website, the Envirosept uses a power
supply and media, therefore produces o-zone as well high resistance
media. The electrostatic filters typically used arrestance test for
efficiency, which has a large particle size dust for testing.

The media filters typically use dust spot test as opposed to arrestance
test used by electrostatic filters. A 95% arrestance rating on an
electrostatic filter is about the same as a 15 to 20% atmospheric dust
spot test. The tests are completely different, therefore no direct
co-relation.

Electrostatic filters don't work well below about 300 Feet per minute
air velocity, because they don't develope a charge below that air
speed. Therefore their high resistance to air flow is their own enemy.
If you oversize electrostatic filters to reduce resistance to air
flow, the velocity drops below the 300 FPM threshold and they loose
effectiveness.

The combination filters like Envirosept and Dynamic are the worst of
both worlfs. They have media which has high resistance to air flow
needs and replaced periodically $$$, and they produce ozone.
Nick, you should get a flow hood and a differential pressure gauge and
test the results before you recommend them to anyone. The saving grace
of the Envirosept is it seems to be a better than average filter, if
you have a powerful enough blower to overcome their high resistance to
air flow. As an option, put two filter grilles side by side, due to
the fan laws, since the velocity is 1/2, the pressure drop will be only
1/4 (the square of the change). Then the Envirosept becomes a more
interesting concept.

Just remember, if you use a high resistance/efficiency filter, your air
will be cleaner, but with reduced air flow your AC may not work well
and your efficiency will be reduced. (Unless you have a high powered
blower or oversized filter.)

Nick, half of the systems that I measure have air flow of 200 CFM/ ton
instead of the 400 CFM/ton they should have. Hence my dislike of high
efficiency/high resistance filters that reduce air flow another 10%
to20%.

Stretch

Stretch wrote:

...the Envirosept uses a power supply and media,

Yes. Less than 2 watts at 7 kV...

therefore produces o-zone as well high resistance media.

It does not produce ozone. I'm not sure what you mean by the rest.

The electrostatic filters typically used arrestance test for
efficiency, which has a large particle size dust for testing.

Here's a basic comparison. "Electrostatic" below means Honeywell
types with fine wires with a high voltage and no charged media:

Typical Ambient Particle
Size distribution (in microns) per m^3 Particle Removal Rates

% by % by Electrostatic ESSA
Size (um.) Count count weight ($800-1200) ($200)

10+ 1,000 .005% 28% xxx x 99% 99+%
5-10 35,000 .175% 52% x x 95% 99+%
1-5 264,000 1.32% 17% x x 85% 99+%
..5-1 1,352,000 6.78% 2% xxx 60% 90+%
..01-.5 18,280,000 91.72% 1% xxx 40% 65%

|||||_ bacteria/viruses/spores
||||_ cooking/tobacco smoke
|||_ household dust
||_ pollen/mold/spores
|_ dander/hair

Average synthetic dust weight arrestance: 79%

Single pass efficiency: 33% @0.3 um, 75% @0.5 um, 95% @1 um, 99% @3 um

Pressure drop: 0.05" @150 lfm, 0.1" @225 lfm, 0.15" @300 lfm, 0.22" @375 lfm

ASHRAE dust holding capacity: 20 gm/ft^2

The media filters typically use dust spot test as opposed to arrestance
test used by electrostatic filters.

I think we are comparing apples to apples above.

Electrostatic filters don't work well below about 300 Feet per minute
air velocity, because they don't develope a charge below that air speed.

I think those "electrostatic filters" are different animals, with no
power supplies. The expensive Honeywell types above work better with
lower flow rates and longer residence times.

The combination filters like Envirosept and Dynamic are the worst of
both worlfs. They have media which has high resistance to air flow
needs and replaced periodically $$$, and they produce ozone.

The Envirosept doesn't. IIRC, the filters cost about $1. I wish they made
a washable filter. That would be a better worlf.

...you should get a flow hood and a differential pressure gauge and
test the results before you recommend them to anyone.

Again, here's the Envirosept spec:

Pressure drop: 0.05" @150 lfm, 0.1" @225 lfm, 0.15" @300 lfm, 0.22" @375 lfm

It's designed to slip into the same space as a passive filter. How do these
pressure drops compare to passive filters and typical duct pressure losses?

As an option, put two filter grilles side by side, due to the fan laws,
since the velocity is 1/2, the pressure drop will be only 1/4 (the square
of the change). Then the Envirosept becomes a more interesting concept.

From the spec above, the fan laws may fit fans better than filters. For
instance, 300 lfm is 2X 150, but dP = 3 vs 4X.

And maybe most blowers can handle higher pressures, or the duct and register
losses are a lot larger than filter losses, so the filter loss doesn't matter
much. I know Envirosept's father Mike Putro, who is one smart cookie, and
honest as well. He's been selling these filters for about 10 years. A larger
housing might be difficult to make, as well as unnecessary.

...half of the systems that I measure have air flow of 200 CFM/ ton
instead of the 400 CFM/ton they should have. Hence my dislike of high
efficiency/high resistance filters that reduce air flow another 10% to 20%.

Which bodily orifice produced your 10-20%? :-) IMO, most modern ACs cool
too much and dehum too little, wasting too much electrical energy in the
blower and too much heat energy through the walls. A fountain or mister
or perspiring human can help distribute coolth to occupied rooms more
dynamically, with less heat gain from the outdoors...

Nick

On 4 Jun 2005 08:18:53 -0700, wrote:

My question is, would this new unit be much more effective (or less
effective) than the old one? I know the old one is working to some
extent, since I can see the dirt come off when it gets cleaned.

For what its worth, after nixing an electronic filter on account of
cost, and "sticky" treated filters on account of cost and reduced
airflow, my solution is to spray a light coat of cooking oil on the
cheapie regular fiberglass filter. My theory is that the oil will
retain dust particles better than a plain filter. I get to change
the filters more often and thus remove the dust permanent instead of
letting it be blown back into the ducts and air. I only did this last
month when the weather no longer required the furnace to run. I
should know when the weather gets cold again whether there is any
problem having cooking oil on the filter for an extended period and
whetehr it picks up dust and better.

PaPaPeng,

The fiberglass filters come from the factory with a coating already on
the filters. They are called viscous impingement filters. Spraying them
with oils not necessary, but will not hurt.

Stretch

Nick,

Some clarifications, using industry standard nomenclature, So that we
are speaking the same language:

"Here's a basic comparison. "Electrostatic" below means Honeywell
types with fine wires with a high voltage and no charged media:"

Nick,
The filters that use electricity to charge plates or media are normally
called ELECTRONIC AIR FILTERS in the trade. While they don't use much
electricity, the power output is usually several thousand to as high as
ten thousand volts. It is the high voltage (low current) that produces
ozone, due to corona discharge effects. The higher the voltage, the
more ozone is produced. Many such filters have ozone reduction options
that reduce the output voltage to reduce ozone generation. This also
reduces their effectiveness and cleaning power. The ELECTRONIC air
cleaners have very low resistance to air flow. If you want a high
efficiency air filter, this is the way to go.



ELECTROSTATIC FILTERS are those that use the high velocity of air to
put a static charge on plastic media, much like rubbing your shoes on a
rug as you walk across a floor. They usually use a couple of different
plastics to enhance the effect. ELECTROSTATIC air filters have no
power supplies.

The envirosept does not fit neatly into either category, as far as I
can see.

Nick, a 20 x 20 fiberglass filter at 800 CFM has a pressure drop of
..08"WG. The net opening of that filter is 18" x 18", or 2.25 Sq. Ft..
800 CFM/2.25 Sq. Ft. = 355 linear feet per minute (FPM). Compare this
to the Envirosept pressure drop of .22" at 375 FPM. At very close
velocities, the Envirosept filter has a pressure drop of just under 3
times that of the fiberglass filter.

The fan laws apply to fans, duct systems and coils. I have also found
it to be very close with air filters that I have tested. Nick, I test
air flow with a flow hood, a hot wire annemometer and a digital
differential pressure gauge. I have been using a flow hood for 17
years. I have been using the other instruments almost as long. I am
not pulling these numbers out of any body oriface as you suggest.
(Have you been hanging around alt.hvac.group too much?? That kind of
language does not belong in an intelligent conversation.)

As to AC systems cooling too much and dehumidifying too little, I agree
there. Paying attention to load calculations and proper air flow would
help tremendously. Most AC systems dehumidify best at air flows of 350
to 400 Cubic Feet per Minute (CFM) per ton. If systems deliver proper
air flow, there would be much less need to oversize them as most
contractors do. If the duct systems matched the equipment better,
instead of being undersized, there would be more blower capacity for
high efficiency filters.

Because so many people now purchase pleated media filters at the home
centers, I recommend Variable Speed (VS) blowers when I sell
replacement systems. Variable Speed blowers are more efficient than
standard blowers. Typically, the SEER goes up at least 1 (12 SEER
increases to 13 SEER) when changing from a standard to a VS blower.
Also, while most standard blowers will produce rated air flow with a
coil installed at .3 to.5 inches water column external static pressure,
a VS blower will produce rated air flow at .8 to 1.0 inches water
column external static pressure. In addition, the VS blower will speed
up as the filter loads up, producing nearly the same air flow at
different filter pressure drops. I have measured this in the field, it
is not just some marketing balony from manufacturers.

I don't dispute that the Envirosept does a MUCH BETTER job of cleaning
the air. My problem with it, and other similiar products is that
significantly reduced air flow adversly affects performance of heating
and cooling systems already installed and designed to work with
standard air filters. That is if any design work was done on them at
all.


Just remember that whole house AC systems are a SYSTEM. Anything you
do to one part of the system affects the rest of the system.

By the way, I would not recomment using a "mister" or swamp cooler here
in South Carolina. Your customer would probably come to blows with you
over that. It might work wellin your climate up in Mass though.
Remember that this group goes to people all over, what works in your
climate may not work in other climates.


By the way #2: What the heck is coolth??


Respectfully yours,

Stretch

On 5 Jun 2005 17:25:57 -0700, "Stretch" wrote:

Nick,

By the way #2: What the heck is coolth??


Something Nick invented, along with his various .... ummmm....
'unusual'....... ideas of phsyics.


Click every day here to feed an animal that needs you today !!!

http://www.theanimalrescuesite.com/

Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/

My 2 cents worth....
Electronic filters work well if they are properly maintained.
Electrostatic filters are not very efficient and cause too much restriction
in the airflow and are unsanitary.
Fiberglass disposables are worthless
3M Ultra Allergen filters create too much restriction in the airflow and are
very expen$ive
A good quality pleated filter with a MERV rating of between 8 and 11 will
get all the nasty particulates out of the air, and not break the bank. Keep
in mind that reguardless of what the label says, (good for up to 3 months),
I recommend that they be changed every month.
When you write the check for your light bill, use that as a reminder to
change the filter....clean filter = better efficiency = lower bills.
--

Steve @ Noon-Air Heating & A/C


Why can't Mr Fork and
Ms Electrical Outlet just get along?

"Stretch" wrote in message
ups.com...
Nick,

Some clarifications, using industry standard nomenclature, So that we
are speaking the same language:

"Here's a basic comparison. "Electrostatic" below means Honeywell
types with fine wires with a high voltage and no charged media:"

Nick,
The filters that use electricity to charge plates or media are normally
called ELECTRONIC AIR FILTERS in the trade. While they don't use much
electricity, the power output is usually several thousand to as high as
ten thousand volts. It is the high voltage (low current) that produces
ozone, due to corona discharge effects. The higher the voltage, the
more ozone is produced. Many such filters have ozone reduction options
that reduce the output voltage to reduce ozone generation. This also
reduces their effectiveness and cleaning power. The ELECTRONIC air
cleaners have very low resistance to air flow. If you want a high
efficiency air filter, this is the way to go.



ELECTROSTATIC FILTERS are those that use the high velocity of air to
put a static charge on plastic media, much like rubbing your shoes on a
rug as you walk across a floor. They usually use a couple of different
plastics to enhance the effect. ELECTROSTATIC air filters have no
power supplies.

The envirosept does not fit neatly into either category, as far as I
can see.

Nick, a 20 x 20 fiberglass filter at 800 CFM has a pressure drop of
.08"WG. The net opening of that filter is 18" x 18", or 2.25 Sq. Ft..
800 CFM/2.25 Sq. Ft. = 355 linear feet per minute (FPM). Compare this
to the Envirosept pressure drop of .22" at 375 FPM. At very close
velocities, the Envirosept filter has a pressure drop of just under 3
times that of the fiberglass filter.

The fan laws apply to fans, duct systems and coils. I have also found
it to be very close with air filters that I have tested. Nick, I test
air flow with a flow hood, a hot wire annemometer and a digital
differential pressure gauge. I have been using a flow hood for 17
years. I have been using the other instruments almost as long. I am
not pulling these numbers out of any body oriface as you suggest.
(Have you been hanging around alt.hvac.group too much?? That kind of
language does not belong in an intelligent conversation.)

As to AC systems cooling too much and dehumidifying too little, I agree
there. Paying attention to load calculations and proper air flow would
help tremendously. Most AC systems dehumidify best at air flows of 350
to 400 Cubic Feet per Minute (CFM) per ton. If systems deliver proper
air flow, there would be much less need to oversize them as most
contractors do. If the duct systems matched the equipment better,
instead of being undersized, there would be more blower capacity for
high efficiency filters.

Because so many people now purchase pleated media filters at the home
centers, I recommend Variable Speed (VS) blowers when I sell
replacement systems. Variable Speed blowers are more efficient than
standard blowers. Typically, the SEER goes up at least 1 (12 SEER
increases to 13 SEER) when changing from a standard to a VS blower.
Also, while most standard blowers will produce rated air flow with a
coil installed at .3 to.5 inches water column external static pressure,
a VS blower will produce rated air flow at .8 to 1.0 inches water
column external static pressure. In addition, the VS blower will speed
up as the filter loads up, producing nearly the same air flow at
different filter pressure drops. I have measured this in the field, it
is not just some marketing balony from manufacturers.

I don't dispute that the Envirosept does a MUCH BETTER job of cleaning
the air. My problem with it, and other similiar products is that
significantly reduced air flow adversly affects performance of heating
and cooling systems already installed and designed to work with
standard air filters. That is if any design work was done on them at
all.


Just remember that whole house AC systems are a SYSTEM. Anything you
do to one part of the system affects the rest of the system.

By the way, I would not recomment using a "mister" or swamp cooler here
in South Carolina. Your customer would probably come to blows with you
over that. It might work wellin your climate up in Mass though.
Remember that this group goes to people all over, what works in your
climate may not work in other climates.


By the way #2: What the heck is coolth??


Respectfully yours,

Stretch

Stretch wrote:

Some clarifications, using industry standard nomenclature, So that we
are speaking the same language:

Good. The first 3 rules of philosophy are "clarify, clarify, clarify."

"Here's a basic comparison. "Electrostatic" below means Honeywell
types with fine wires with a high voltage and no charged media:"

The filters that use electricity to charge plates or media are normally
called ELECTRONIC AIR FILTERS in the trade.

I also think "electrostatic precipitator."

While they don't use much electricity, the power output is usually several
thousand to as high as ten thousand volts.

Maybe higher. I built one years ago with a 1B3 and a TV flyback transformer.

...The ELECTRONIC air cleaners have very low resistance to air flow.
If you want a high efficiency air filter, this is the way to go.

Except for the price, cleaning task, zappy noises, and ozone... I'm not
sure they all produce ozone. The Ionic Breeze doesn't, altho it puts all
the dirt on the walls of the room :-) I put one inside a 12" grounded
stovepipe with a light bulb below to make some airflow, and it worked
as an electrostatic precipitator.

...a 20 x 20 fiberglass filter at 800 CFM has a pressure drop of .08"WG.

OK.

The net opening of that filter is 18" x 18", or 2.25 Sq. Ft...
800 CFM/2.25 Sq. Ft. = 355 linear feet per minute (FPM). Compare this
to the Envirosept pressure drop of .22" at 375 FPM. At very close
velocities, the Envirosept filter has a pressure drop of just under 3
times that of the fiberglass filter.

I wonder how important that is, given some blower overcapacity and
the rest of the pressure losses in the duct/register/plenum system.
What's a typical total?

Grainger's 5C092 direct drive furnace blower (with a 9.5" 1075 rpm wheel
and a 1/4 HP motor) is rated 1529 cfm at 0.3" sp, 1517 at 0.4, 1483 at 0.5,
1416 at 0.6, 1326 at 0.7, 926 at 0.8, and 397 at 0.9. Adding 0.22-0.08
= 0.14" wouldn't make much difference over the low part of that range.

The fan laws apply to fans, duct systems and coils. I have also found
it to be very close with air filters that I have tested.

Not the Envirosept, with 3X vs the fan-law 4X pressure drop at 2X flow.
We also need to consider the operating point on the blower curve, IMO.

I am not pulling these numbers out of any body oriface as you suggest.

They don't seem unreasonable. If the blower above is working in the middle
of its range at 0.6" and 1416 cfm and we add 0.14", the output might drop
to 1326-(0.74-0.7)/0.1(1326-926) = 1166 vs 1416 cfm... 18% less.

As to AC systems cooling too much and dehumidifying too little, I agree
there. Paying attention to load calculations and proper air flow would
help tremendously. Most AC systems dehumidify best at air flows of 350
to 400 Cubic Feet per Minute (CFM) per ton.

Seems to me they could dehumidify better and better at lower velocities.

...the VS blower will speed up as the filter loads up, producing nearly
the same air flow at different filter pressure drops.

Sounds like a fix for the Perils of Pressure Drop.

...I would not recomment using a "mister"... here in South Carolina.

I might, in conjuction with a low-flow AC that mainly dehumidifies.
You might think of this as an alternative to variable air volume, or
"dynamic balancing," with less blower power and duct and house heat
losses. Why cool a room if nobody's in it? A little misting can lower
the air temp in an occupied room while the rest of the house air is
warmer and drier, with less coolth moving out through the walls.

It might work wellin your climate up in Mass though.

I'm near Phila. We only need home AC for 1-2 weeks per year mostly in our
tropical August climate when night temps and RHs stay over 70 F and 70%.
Even then, ceiling fans are a good alternative.

By the way #2: What the heck is coolth??

The opposite of heat. It's equally ambiguous, since it can mean a flow
(heat power in Btu/h) or a quantity of energy (stored heat in Btu).
Coolth flows from cooler to warmer objects. Google shows lots of use.

Nick

wrote:

By the way #2: What the heck is coolth??

Something Nick invented, along with his various .... ummmm....
'unusual'....... ideas of phsyics.

It's very advanced. I didn't invent it until after taking high school
physics, college physics, statics, dynamics, materials science,
electromagnetics, quantum mechanics, and solid state physics.

But I couldn't have done it alone. It was really a team effort.
My entire staff deserves praise.

Nick

Stretch wrote:

As to AC systems cooling too much and dehumidifying too little, I agree
there. Paying attention to load calculations and proper air flow would
help tremendously. Most AC systems dehumidify best at air flows of 350
to 400 Cubic Feet per Minute (CFM) per ton.

If it's 90 F outdoors with w = 0.012 and 80 F with w = 0.012 indoors
and we move 400x60xrho = 2400Rho pounds per hour of air into a room
with 0.24 Btu/lb of specific heat and 2400Rhox0.24(80-T) = 12K Btu/h and
Rho = 39.38/(460+T) lb/ft^3, T = 53.9 F, with HVAC business as usual.

...I would not recomment using a "mister"... here in South Carolina.

I might, in conjuction with a low-flow AC that mainly dehumidifies.
You might think of this as an alternative to variable air volume, or
"dynamic balancing," with less blower power and duct and house heat
losses. Why cool a room if nobody's in it?

If we move C cfm of 40 F saturated air with ws = 0.005216 into a room
and mist a pound to wr = 0.012, that makes 1000(wr-ws) = 6.78 Btu of
coolth. Raising a pound makes 0.24(80-40) = 9.6 Btu. The total is 16.38,
and 40 F air weighs 0.07876 lb/ft^3, so 60Cx0.07876x16.38 = 12K Btu/h
makes C = 155 vs 400 cfm, with smaller ducts or (400/155)^3 = 17 times
less blower power, and...

A little misting can lower the air temp in an occupied room while
the rest of the house air is warmer and drier, with less coolth
moving out through the walls.

Nick

Nick

define your terms!

What is coolth?

What is xrho? Or is that x rho?

Please put spaces around your =, +, /, * (operators) Your posts are
hard to read and you need to define your terms. Example: I use
grains, you use decimal fractions, eg 0.012 vs 84 grains. It would be
easier to understand you if you use standard terms and defined what is
not standard. For the sake of other people, please define everything.

Stretch


wrote:
Stretch wrote:

As to AC systems cooling too much and dehumidifying too little, I agree
there. Paying attention to load calculations and proper air flow would
help tremendously. Most AC systems dehumidify best at air flows of 350
to 400 Cubic Feet per Minute (CFM) per ton.

If it's 90 F outdoors with w = 0.012 and 80 F with w = 0.012 indoors
and we move 400x60xrho = 2400Rho pounds per hour of air into a room
with 0.24 Btu/lb of specific heat and 2400Rhox0.24(80-T) = 12K Btu/h and
Rho = 39.38/(460+T) lb/ft^3, T = 53.9 F, with HVAC business as usual.

...I would not recomment using a "mister"... here in South Carolina.

I might, in conjuction with a low-flow AC that mainly dehumidifies.
You might think of this as an alternative to variable air volume, or
"dynamic balancing," with less blower power and duct and house heat
losses. Why cool a room if nobody's in it?

If we move C cfm of 40 F saturated air with ws = 0.005216 into a room
and mist a pound to wr = 0.012, that makes 1000(wr-ws) = 6.78 Btu of
coolth. Raising a pound makes 0.24(80-40) = 9.6 Btu. The total is 16.38,
and 40 F air weighs 0.07876 lb/ft^3, so 60Cx0.07876x16.38 = 12K Btu/h
makes C = 155 vs 400 cfm, with smaller ducts or (400/155)^3 = 17 times
less blower power, and...

A little misting can lower the air temp in an occupied room while
the rest of the house air is warmer and drier, with less coolth
moving out through the walls.

Nick

On 6 Jun 2005 07:07:01 -0700, "Stretch" wrote:

Nick

define your terms!

What is coolth?

And when exactly did it learn to walk through walls ??? :-)

not standard. For the sake of other people, please define everything.

the rest of the house air is warmer and drier, with less coolth
moving out through the walls.

Welcome to NickLand, Stretch, where 'the old concepts of
reality' just don't quite apply any more' :-)


Click every day here to feed an animal that needs you today !!!

http://www.theanimalrescuesite.com/

Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/

Stretch wrote:

Nick

Hiya Stretch,

define your terms!

OK.

What is coolth?

Btu/h of cooling.

What is xrho? Or is that x rho?

x means times, Rho is a density.

Please put spaces around your =, +, /, * (operators)

You might consider mentally adding such spaces as you require.

...I use grains, you use decimal fractions, eg 0.012 vs 84 grains.

w = 0.012 is a humidity ratio, eg pounds of water per pound of dry air.

If it's 90 F outdoors with w = 0.012 and 80 F with w = 0.012 indoors
and we move 400x60xRho = 2400Rho pounds per hour of air into a room
with 0.24 Btu/lb of specific heat and 2400Rhox0.24(80-T) = 12K Btu/h and
Rho = 39.38/(460+T) lb/ft^3, T = 53.9 F, with HVAC business as usual.

...I would not recomment using a "mister"... here in South Carolina.

I might, in conjuction with a low-flow AC that mainly dehumidifies.
You might think of this as an alternative to variable air volume, or
"dynamic balancing," with less blower power and duct and house heat
losses. Why cool a room if nobody's in it?

If we move C cfm of 40 F saturated air with ws = 0.005216 into a room
and mist a pound to wr = 0.012, that makes 1000(wr-ws) = 6.78 Btu of
coolth. Raising a pound makes 0.24(80-40) = 9.6 Btu. The total is 16.38,
and 40 F air weighs 0.07876 lb/ft^3, so 60Cx0.07876x16.38 = 12K Btu/h
makes C = 155 vs 400 cfm, with smaller ducts or (400/155)^3 = 17 times
less blower power...

Nick

On 5 Jun 2005 16:24:04 -0700, "Stretch" wrote:

The fiberglass filters come from the factory with a coating already on
the filters. They are called viscous impingement filters. Spraying them
with oils not necessary, but will not hurt.

Stretch


My concern is when I change the regular furnace filter the dust on it
is dry, loose and easily blown back into the ducts. But if there is an
oil stain anywhere in the house the dust particles get stuck on the
oil stain. Hopefully the dust particles will stick better to an oil
coated furnace filter.

An idea that just came to mind is to have a small heated oil reservoir
infront of the filter element. The concept is everytime the furnace
fires up the heater element will be switched on to vaporize a little
oil and deposit a fresh sticky coat. The vapor will be deposited onto
the filter by the air drawn into the furnace.

Cooking oil deposits inside the ducting is likely a health and
maintenance concern. But what about aromatic oils meant for household
use, as in those wall plug-in gizmos? In fact it is easy enough to
install several of these vaporizers in the cold air return plenum and
tie that to the furnace ON circuit. The vapor may do a double duty of
helping to attract dust onto the filter element first before doing its
original purpose to make the rooms smell nice.



Criticisms? Suggestions?

Nick, I will reply later.

Currently working 8:00 AM to 10:00 PM. (AC contractor) not much time
for the internet right now.

Stretch

In ye olde days beforeth ye global warming ye climate was much more
coolth

..22" is a very significant load on a blower in a residential furnace.

You have internal losses of the fan cabinet (air entering the fan),plus
a non ducted loss probably 1.25 times the velocity head of the
discharge from the fan for a blow through application, the pressure
loss of pushing air through a heat exchanger, perhaps 0.25 or more
inches through a wet coil and then leaving something some pressure for
the ductwork.

The blower on a furnace probably will handle 0.5" of external static.
If this filter system is 0.22 inches when clean, it will soon clog up
and the pressure drop will increase. Would need an oversized blower
to run this filter with central AC on a furnace, filter would eat up
pressure normally reserved for the cooling coil,.

It can be argued that reduced airflow gives more dehumidification, but
also be aware that in heating reduced airflow results in cycling on
high limit and premature failure of heat exchangers.

May work problem free in a climate where required cooling CFM was lower
than required heating CFM, say a 75MBH 90% furnace with a 50F ATR and
1.5 to 2 tons of cooling.

I am surprised at your intrest in this POS system when you could just
patent "Nick's Idiotic Breeze".

Put an old 14" monitor inside a 20x20 box add a throw away filter and a
grainger fan and you will catch more dust than an ionic breeze. Throw
in some swedish microfibre cleaning cloths and an access door and you
are all set. Installation is easy, just need a duplex receptacle to
plug in the blower and monitor.

sayeth the Pineth "If we move C cfm of 40 F saturated air with ws =
0.005216 into a room
and mist a pound to wr = 0.012, that makes 1000(wr-ws) = 6.78 Btu of
coolth. Raising a pound makes 0.24(80-40) = 9.6 Btu. The total is
16.38,
and 40 F air weighs 0.07876 lb/ft^3, so 60Cx0.07876x16.38 = 12K Btu/h
makes C = 155 vs 400 cfm, with smaller ducts or (400/155)^3 = 17 times
less blower power, and..."

Factor in the pressure drop of the custom built 10 row, 14 fin per inch
cooling coil, that will take 80 degree air down to saturated at 40F.

or add an air washer to the end of your Idiotic Breeze

Wow! No idea I'd start such a debate.

I guess my interpretation of all this puts me off the idea of the
Envirosept due to the decreased airflow. So, the question then
becomes, should I replace the old 1976 Honeywell electronic air cleaner
with a new one of the same type, or has the technology not changed
during that time? Would an upgrade be worth the expense?

Thanks!

Thanks! Does the Aprilaire cause less airflow reduction than the
Envirosept then?


Steve Scott wrote:
I suggest looking at Aprilaire's model 5000. It gives the best of
both worlds.
http://tinyurl.com/9dvon

On 8 Jun 2005 07:21:58 -0700, wrote:

Wow! No idea I'd start such a debate.

I guess my interpretation of all this puts me off the idea of the
Envirosept due to the decreased airflow. So, the question then
becomes, should I replace the old 1976 Honeywell electronic air cleaner
with a new one of the same type, or has the technology not changed
during that time? Would an upgrade be worth the expense?

Thanks!


--
Do vegetarians eat animal crackers?