I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.

DONT PANIC! the weather is extreme, are your windows dual pane?

in any case the humidifier is causing this its normal so dont worry
about it.

with higher humidity you can keep the thermostat lower

"c_shah" wrote in message
oups.com...
I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.

Sounds about normal for that combination of outdoor temperature and high
humidity. Try setting it a bit lower if it is a problem.

wrote:

with higher humidity you can keep the thermostat lower

And LOSE money.

Nick

These windows are new..they are thermopane windows (double pane
windows) I was just curious because they were new and might have start
leaking

Thanks for your reply

wrote in message
...
wrote:

with higher humidity you can keep the thermostat lower

And LOSE money.

Nick


Nick, what do you suggest to make the air comfortable to breath if not a
humidifier?

"c_shah" wrote in message
oups.com...
I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.


I've seen this happen much more than usual when people close the shades at
night, particularly if the shades are insulating type. You need to get the
warm air to flow up and over the glass. If so, just cracking open, or
opening completely, the shades while you sleep will greatly reduce the
amount of ice that builds up by morning.

wrote:
with higher humidity you can keep the thermostat lower


And LOSE money.

Nick

Ahh the heat loss is the same at 10% humidity or 50%

BUT!

The occupants will be more comfy at a lower temperature, with higher
humidity.

Its condensation on your windows that is freezing. Its normal for
extreme low temps. When the temp is not extremely low it will be
just water/condensation on your windows.

On 19 Feb 2006 04:07:02 -0800, "c_shah"
wrote:

I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.

c_shah wrote:
I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.

It means the dew point of the air in your home is greater than the
temperatures of the inside of those windows and that that temperatures is
below 32º F.

If it is just an occasional thing, it is nothing to worry about. If it
happens often it will damage the windows.(the wood parts)

Correction means decreasing the humidity and therefore the dew point and
or increasing the temperature of the inside surface of the window.

The first means reducing the humidity and or the air temperature. The
second means maybe adding a storm window or using multi-paned windows where
there are single panes now.

If you have curtains or drapes over the windows and close them at night,
it will help keep the room warm, but it means the inside window surface will
be colder yet the air's dew point will be the same. Increasing air
circulation to the windows can help.


--
Joseph Meehan

Dia duit

If there wood windows I would be wiping out the moisture when the ice
melts,so the wood does not have to be re-stained or painted, keep the drapes
or blinds closed when the temp gets into the single digits. I think that ice
build up when the temps dips to single digit is inevidenable, the only way
to cure this is with a storm window, outside the new windows, that would
reduce the glass temp on the inside of the house.

A humidity guage would be nice to see what the actual humidity is in your
house.

I have the same problem and do not run the power humidifer in the winter and
still have what is considered normal humidity in the house in the winter
months. I do wipe out the water as needed and about every 3 years re-finish
the lower wood sill of the windows. My windows are thermopane.

Tom



"c_shah" wrote in message
oups.com...
These windows are new..they are thermopane windows (double pane
windows) I was just curious because they were new and might have start
leaking

Thanks for your reply

wrote:

with higher humidity you can keep the thermostat lower

And LOSE money.

Ahh the heat loss is the same at 10% humidity or 50%

Not really, since evaporating water takes energy and houses leak air.
To raise indoor RH AND reduce the fuel bill, caulk the house.

Nick

Newsgroups: alt.home.repair
Subject: Winter humidification wastes energy
Date: 11 Feb 2005 08:33:11 -0500
Organization: Villanova University

Sent: Monday, January 17, 2005 8:58 AM

Subject: Attn: president/legal--Winter humidification wastes energy

Gentlemen,

I suspect that winter humidification wastes vs saves heating energy, and
the savings claim is an energy myth. People tend to forget that evaporating
water takes heat energy, and that heat energy has to come from somewhere,
even if something like a humidifier belt motor uses little energy by itself.

The heat saved by turning a thermostat down appears to be far less than
the extra heat used to evaporate water, in all but extremely tight houses
with little insulation, eg submarines.

http://lennox.com/pdfs/brochures/Len...umidifiers.pdf claims
that 69 F at 35% RH and 72 F at 19% RH are equally comfortable, but the BASIC
program in the new ASHRAE 55-2004 comfort standard predicts that 69 F and 35%
RH and 69.7 at 19% RH are equally comfortable (PMV = -0.537, see below.)

If a 2400 ft^2 tight house has 0.5 ACH and say, 400 Btu/h-F of conductance,
turning the thermostat down from 69.7 to 69 saves (69.7-69)400 = 280 Btu/h.

Air at 69 F and 100% RH has humidity ratio w = 0.015832 pounds of water per
pound of dry air, so 19% air has wl = 0.00301, and 39% air has wh = 0.00617.
Raising 69 F air from 19 to 39% requires evaporating wh-wl = 0.00316 pounds
of water per pound of dry air. Dry air weighs about 0.075 lb per cubic foot.

With 0.5x2400x8/60 = 160 cfm or 9600 ft^3/h or 720 pounds per hour of
air leakage, raising the indoor RH from 19 to 39% requires evaporating
720x0.00316 = 2.275 pounds of water per hour, which requires about 2275
Btu/h of heat energy, so it looks like humidifying this fairly airtight
house wastes 2275/280 = 8 times more energy than it "saves." And many
US houses are less airtight, so humidification would waste more energy.

Please modify your energy-savings claim.

Thank you.

Nick Pine

10 SCREEN 9:KEY OFF
20 CLO=1'clothing insulation (clo)
30 MET=1.1'metabolic rate (met)
40 WME=0'external work (met)
50 DATA 69,35,69.74,19
60 FOR CASE=1 TO 2
70 READ TC,RC
80 TA=(TC-32)/1.8'air temp (C)
90 TR=TA'mean radiant temp (C)
100 VEL=.1'air velocity
110 RH=RC'relative humidity (%)
120 PA=0'water vapor pressure
130 DEF FNPS(T)=EXP(16.6536-4030.183/(TA+235))'sat vapor pressure, kPa
140 IF PA=0 THEN PA=RH*10*FNPS(TA)'water vapor pressure, Pa
150 ICL=.155*CLO'clothing resistance (m^2K/W)
160 M=MET*58.15'metabolic rate (W/m^2)
170 W=WME*58.15'external work in (W/m^2)
180 MW=M-W'internal heat production
190 IF ICL.078 THEN FCL=1+1.29*ICL ELSE FCL=1.05+.645*ICL'clothing factor
200 HCF=12.1*SQR(VEL)'forced convection conductance
210 TAA=TA+273'air temp (K)
220 TRA=TR+273'mean radiant temp (K)
230 TCLA=TAA+(35.5-TA)/(3.5*(6.45*ICL+.1))'est clothing temp
240 P1=ICL*FCL:P2=P1*3.96:P3=P1*100:P4=P1*TAA'intermed iate values
250 P5=308.7-.028*MW+P2*(TRA/100)^4
260 XN=TCLA/100
270 XF=XN
280 EPS=.00015'stop iteration when met
290 XF=(XF+XN)/2'natural convection conductance
300 HCN=2.38*ABS(100*XF-TAA)^.25
310 IF HCFHCN THEN HC=HCF ELSE HC=HCN
320 XN=(P5+P4*HC-P2*XF^4)/(100+P3*HC)
330 IF ABS(XN-XF)EPS GOTO 290
340 TCL=100*XN-273'clothing surface temp (C)
350 HL1=.00305*(5733-6.99*MW-PA)'heat loss diff through skin
360 IF MW58.15 THEN HL2=.42*(MW-58.15) ELSE HL2=0'heat loss by sweating
370 HL3=.000017*M*(5867-PA)'latent respiration heat loss
380 HL4=.0014*M*(34-TA)'dry respiration heat loss
390 HL5=3.96*FCL*(XN^4-(TRA/100)^4)'heat loss by radiation
400 HL6=FCL*HC*(TCL-TA)'heat loss by convection
410 TS=.303*EXP(-.036*M)+.028'thermal sensation transfer coefficient
420 PMV=TS*(MW-HL1-HL2-HL3-HL4-HL5-HL6)'predicted mean vote
430 PPD=100-95*EXP(-.03353*PMV^4-.2179*PMV^2)'predicted % dissatisfied
440 PRINT TC,RC,PMV
450 NEXT CASE

69 35 -.5376486
69.74 19 -.5372599

Engineering VP Mark Hogan said Lennox was embarrassed by all this and
he didn't know where their numbers had come from, and he thanked me
for bringing this to their attention and said they are changing their
printed brochures and Aprilaire web site energy-savings claim.

This reminds me of David and Goliath :-)

Nick

As the outdoor temperature drops, you are supposed to drop your indoor
humidity. This is from the Aprilaire web site:
Outdoor Temp(F) Humidistat setting(%)
40 45
30 40
20 35
10 30
0 25
-10 20
-20 15

The purpose of doing that is prevent condensation on cold surfaces (IE:
windows). I had one house that had frost develop on the wallboard nail
heads. OF course the indoor humidty was way too high and it was -15F outside
(Chicago area)


"c_shah" wrote in message
oups.com...
I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.

On 19 Feb 2006 04:07:02 -0800, "c_shah"
wrote:

I live in a suburb of Chicago, It is around -3 degree Fahrenheit, I
wake up this morning and found ice on all of my bedroom and kitchen
windows. What does this indicate? Do I have leaky windows? I kept
humidifier (aprilaire - attached with my furnace) to 35%.

No. Humidity from indoors condenses and freezes on the windows--no so
uncommon. Make sure to wipe up the water as soon as it melts to
prevent damage. Ideal humidity is 50%.

wrote:
wrote:


with higher humidity you can keep the thermostat lower


And LOSE money.

Nick


Are you talking about the money it takes to put the water into the air?
Thats really not all that much.


--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

Dunno about the 50% RH being "ideal." IME, it's whatever's sufficient
to avoid respiratory problems, without notable condensation on windows
of cooler parts of house.

In the case I'm familiar with, those windows are low-e, with original
el-cheapo storms, and the humidistat is set to around 25% RH.

If moisture is condensing on glass, consider what's happening inside
wall cavities and above the ceiling too.

J

dnoyeB wrote:
wrote:
wrote:

with higher humidity you can keep the thermostat lower

And LOSE money.

Are you talking about the money it takes to put the water into the air?
Thats really not all that much.

It's about ten times the lowered thermostat savings :-)

Nick

I read one of the posts mentioning that when outside temperature is too
cold you should change the humidifier setting to around 25%. But I have
aprilaire automatic humidifier (model 600) and it says that computer
controlled and has been installed right before return air enteres into
the furnace. Do I still have to adjust the humidifer settings?

Thanks in advance

Original Poster

On 20 Feb 2006 09:51:08 -0800, "c_shah"
wrote:

I read one of the posts mentioning that when outside temperature is too
cold you should change the humidifier setting to around 25%. But I have
aprilaire automatic humidifier (model 600) and it says that computer
controlled and has been installed right before return air enteres into
the furnace. Do I still have to adjust the humidifer settings?

Thanks in advance

Original Poster


Keep the air around 50% for the best comfort. This is also best for
furniture and electronic equipment. Twenty-five percent is very dry.
Cooler air holds less water than warmer air. Converting liquid water
to water vapor requires adding lots of energy. Cover ting solid water
(ice) to liquid water requires energy, but not nearly as much. You
can increase humidly by using vaporizers or lots of plants.