window condensation inside...

[M&B]

hey all, i've been having a problem for a while in the winters with condensation forming on the windows. i had wood double hung windows with triple track storm windows which i replaced this spring w/ a very good vinyl replacement window. and just recently re-sided w/ a layer of 1/2" foam and vinyl siding. we've had a few nights dip into the mid to lower 30's and now in the morning condensation on the windows. we keep a dehumidifyer in the basement and the humidity level down there is usually about 47% at about 65 degrees F. up stairs (it's a 1,400 sqft. ranch) where we are having the problem the humidity level is just about the same but can range from 45%-57% and the them usually goes no lower than 63 degrees F in the house. there is never condensation on the basement windows. once the temp outside warms up and the heat in the house gets going the condensation will dry up after i wipe most of it away. the thermostat for the house is set to 68 degrees during the day and 63 at night. when we first bought the house i added more insulation to the attic, hoping that i could solve the problem but it didn't help and i hoped that with the new windows it would solve the problem peroid, but it hasn't. any help would be appreciated.

mike.......

[mark Ransley]

You added insulation and windows to fix a humidity problem? That would only increase it. Are you sure you have a good humidistat, calibrated, they should be calibrated every few years. Most purchased are way off. I just bought a taylor, its 15% off. Take a moist rag wrap around humidistat for 30 min it should read 94 to 96 , recalibrate if it doesnt. Did you put foam sheet insulation, does your house have tyvek . do you have a condensing furnace. Your house isnt breathing enough its to tight, you should get a blower door test, infiltration, test. You probably need an air exchanger to move fresh air. Your new windows, what brand , low e , argon, dual pane do you vent cooking and showers outdoors, For now open a few windows, air it out see how low humidity goes, leave a few cracked open see how much of a difference it makes Find your true humidity, and get some testing done on air exchange.

[M&B]

the house is a 40 year old ranch and in the attic there was only a minimal amount of fiberglass insulation so i added more on top of what was there, nothing excessive. i have forced hot air heat and do not have a humidistat on it and we re-sided on the rear and 2 sides of the house over asbestos and went down to the tar paper in the front and used foam board over that then the new vinyl. the windows are certainteed w/ 3/4" double glazed insulated insulated units. i've been involved in the glass installation and replacement field for many years and i've never experienced this. the wireless hygrometer i have is a decent one which gives within 2% accuracy of the Relative Humidity that is given from the weather channel and the Weather bug program i have. how much lower should the RH be in the house than 45%-

50%.

thanks,

mike.......

[TURTLE]

This is Turtle.

It cases like this Moving of air in the room will stop this. another one here is the Double insulted windows are not suppose to do this so I think the Gas inbetween the two glasses is gone / defective double insulted windows. Here is a list of cures below.

Ceiling fan Box fan Central unit with fan running all the time. New Double insulted windows Anything that will move air over the window.

TURTLE

[mark Ransley]

Certainteed windows are good, Consumer reports tested alot of windows , one test was condensation, I have pella and anderson , the pella fog , anderson dont, see how they rate yours. Humidity acuracy is tougher, so you put yours outside and it corresponded to the tv. It may work. And be right. But Im Quoting Taylor instruments now; " Humidity meters measure relative air mosture indoors only, not the outdoor humidity reported by the weather bureau. These instruments register percentage of water which is actualy present in the room compared with the maximum amount of water vapor that could be present. " If yours is correct that is a safe level. but that also depends on outside temps and humidity, if you are in the dry cold now id say you are to high , im 50` and raining and im at 51% , and my house IS to tight. but i dont condense on pellas till 20 outside, at night. I still think you have a tight house. I can lookup some numbers on RH vs Temperature , how cold is your area now. I put foam board on , new windows , the whole works. Last year i couldnt run my new April Air automatic humidifier, im to humid now. Now I need a fresh air recovery system, or a second dehumidifier . I am getting a scond blower test. You save money by insulating, but can create a new issue.

[mark Ransley]

I just read that when you first turn your furnace in fall its normal for windows to fog because you built up high humidity from summer , and your house should dry out as you use your heat. Is your attic vented well. If its above 40 you should be around 40%

[jim]

in the summer time go outside in the 90's with a glass of cold ice water.. the glass sweats on the outside(why??? because the outside of the glass is warmeer than the inside of the glass with the icewater.... the same thing with the house only reverse.... now do the same thing with a foam cup(cold water inside and there is no condensation on the outside of the foam cup... why?? becasue the cut in insulated and the cold on the inside does not go to the outside of the cup..... its moisture inside the house and a higer heat in the house than outside that make the condensation on the glass windows.... that is why it sweats..... not much you can do about it the cold it traveling through the glass.. it does not matter how much insulation you put in the walls or ceiling it will not stop the glass from sweating... the only thing that will stop the glass from sweating is it you leave all the windows and doors open so the inside of the house is just as cold as the outside..

[M&B]

we have 3 gable vents, 1 on each side and one in the front.

the previous owner has fiberglass insulation installed in the basement just between the floor joists and the sill plate to protect from outside air, i've been thinking about removing that fiberglass and seeing if that helps. this has been an on going problem for years and it's getting real frustrating to go thru this every day of the winter. the thing is it's only at night and usually when it's cold and dry outside not cold and damp.

anything else that comes to mind lemme know.

thanks,

mike...........

[M&B]

before i bought my windows i went to the consumers site and took their advice and bought the BrynMaur series since i've never been too fond to the Pella windows. what is a fresh air recovery system? we used a dehumidifier in the house for a couple winters and it didn't help much even though we did pull a lot of water from the air, but our sinuses were always dry and esaily irritated and this has become a thing of major frustration.

if you can think of anything else lemme know.

thanks,

mike...............

[mark Ransley]

How many kids, no bath vent fan, put one in. there is a big part of your problem. Kitchen vent fan? Does your furnace use outside air. Does your drier vent outside. Attic vent size is determined by sq ft of attic, a ranch has alot of sq ft. Leave basement insulation. A vent recovery system i think they are called, or air exchange system brings in fresh air and warms it through a heat exchanger so you dont waist energy as if you opened a window . some dehumidify . Dry sinuses, maybe you need more air exchanges in the house, Check your humidistat for accuracy and get another one.

[M&B]

it sounds like it's correct but it's not or every window in a cold climate would have that problem. nice try though.

mike.......

[M&B]

my windows are brand new, i just installed them in May.

i have ceiling fans in every room and they seem to help a little. i keep them on low in reverse to move the air but not make it too breezy and chilly for the kids at night.

thanks,

mike.............

[M&B]

3 kids, plus myself and my wife.

no bath vent fan, put one in. there is a big part of

Kitchen vent fan? no. but usually just need it when water is boiled.

No it doesn't, can it be made to use outside air? it has a central A/C in with it will that effect the A/c in the summer?

Does your drier vent outside. Yes it does.

This was just with the dehumidifier in the house not in the basement.

thanks,

mike..........

[TURTLE]

This is Turtle.

Let me be a little more clear here. Double insulted window DO NOT SWEAT ON THE INSIDE without one of these things going wrong.

There is 1 of 4 things going on here.

1) You have a bad air leak around the window area.

2) You have 100% RH in your home.

3) You have defective double insulted window with the gas gone out of the inter area between the double glasses.

4) You have blinds that seal the ceiling fan air off from passing over the window area.

1 of these things is going on.

TURTLE

[mark Ransley]

Turtle you are batting Zero 1 New windows, good quality 2 its normal when heat first comes on in fall 3 he needs more fresh aire 4 blinds are affecting solar gain. true but not relevant.

[Frogleg]

Hmmm. As I understand it, water condenses according to two factors: the amount of water IN the air, and the temperature differential between the air and the condensing surface. So condensation can form when the humidity is very high, or when the temperature differential is extreme, or some in-between combination. You mention a measured indoor humidity of 47% at a temperature of 65F. According to a nifty little dew-point calculator

your dew point is about 44F. If the inside surface of your windows is

44F or lower, you will have condensation. Insulating your house and attic will reduce heating costs, but if you have very cold window surfaces, condensation will still occur.

[TURTLE]

this is Turtle.

I just can't buy the ideal of Double pain windows sweating with 0ºF or above outside and 60ºF or above inside the house. this is the reason you buy them in the first place except for heat lost. Maybe it's just me but I think different about things when I see them for years.

Now if you have moisture / Air between the pains. It will sweat. If it has the N2 still there I THINK they should not sweat.

TURTLE

[mark Ransley]

My house is to tight and I have Pella and anderson, LowE Argon dual pane, My pellas fog at around 35 outside , They just are not as good as Anderson. They are rated for Condenstion Resistance Factor CRF. Which I paid no attention to. I need an Air Exchanger. The tighter the house , the more likley condensation. They are all different. Consumer Reports rated them for condensation , and Pellas were rated poor. Oh well

[TURTLE]

I had two bay window put in about 2 years ago with anderson double insulated glass and the Anderson rep. garrentied me they would not sweat down to freezing weather but at 25ºF or below there maybe some sweating but little or none to speak of. It's been 2 years and we don't get much cold weather but down to 25 or so at the lowest and i have never seen any sweating on them. I have some other single window and they sweat up a storm. I have to run the ceiling fans to keep them from flooding everything.

i just may have this not sweating in my brain for looking for it ohn these type window.

TURTLE