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-   -   Ice on window frame (http://www.diychatroom.com/f104/ice-window-frame-196012/)

ajr81 02-11-2014 08:42 PM

Ice on window frame
 
I have a newer house that has basement windows poured into the foundation. When the temperature drops to 5 degrees or colder, I get serious ice build up on the metal window frame. I live in South Dakota, so we have a lot of days with these cold temps. I realize that humidity is the main culprit, but the humidity in the basement is less that 25%. I have two dehumidifiers going at all times and I really can't get the humidity any lower.

As you can see from the picture, the ice is only on the metal frame, not the window itself. Are there any options to fix this other than reducing the humidity further? I read about Closed-Cell Foam Tape Self-Adhesive Weather stripping on another thread, but I don't know. I would really appreciate your help.

http://boards.diynetwork.com/eve/for.../Y/window1.jpg

HomeSealed 02-11-2014 09:56 PM

Metal frames are very conductive, as illustrated by the fact that the ice is on the frame, not the glass. If you don't care about the light/ventilation, throw some rigid foam in there to cover them. Otherwise, I don't see a solution short of replacement... Btw, I'd say that you have more than 2 dehumidifiers going down there, as those windows are essentially serving that same purpose.

ajr81 02-12-2014 08:48 AM

Thank you for your response. What are my replacement options? I figured that since the metal fame is poured into the foundation, it is there for good. Isn't it load bearing too? Thanks again!

joecaption 02-12-2014 09:13 AM

Windows are not load bearing.
It's what's above it that is.
Hard to suggest something without a picture.
Often times the old window frame can be cut out, pressure treated lumber used as new jambs and a new vinyl double pane window added.

creeper 02-12-2014 09:29 AM

Wouldn't it just make sense to wipe off the condensation before it freezes. I wipe out my windows for the same reason every couple of days. I find the ice melts by mid day.

SeniorSitizen 02-12-2014 09:31 AM

Insulating from the outside will allow the metal to warm to nearer indoor temperature and prevent the material reaching dew point temperature and below. Any insulating material placed inside will block indoor temperature from reaching the metal and frost will prevail.

HomeSealed 02-13-2014 07:18 AM

If it is sealed from the inside, interior moisture will not get to it, so no frost. Blocking off from the outside is fine though too.
As joe said, the window is not load bearing and can be cut out for replacement. Vinyl and glass block are probably the most common replacement options.

SeniorSitizen 02-13-2014 09:11 AM

[QUOTE=HomeSealed;1306002]If it is sealed from the inside, interior moisture will not get to it, so no frost. Blocking off from the outside is fine though too.
As joe said, the window is not load bearing and can be cut out for replacement. Vinyl and glass block are probably the most common replacement options.[/QUOTE
***********************************************

You are correct "If it is sealed" and you forgot the vacuum part.

Now tell us how a home owner or contractor is going to vacuum that space, as double pane windows are made, using a low conductive gas such as Argon to bring the dew point temperature down in the -35F range.

It ain't going to happen.

Windows on Wash 02-13-2014 11:45 AM

Rigid foam, cut to fit, and caulked to the concrete will keep the most of the moisture from reaching the frame. Regardless of inside or outside approach, it will have to be sealed to be effective.

SeniorSitizen 02-13-2014 12:38 PM

Whatever benefits the OP but he/she should understand that for example:

If when the air present at the window, when it is ( perfectly ) pre - sealed sealed from the outside and insulated and ( perfectly ) sealed on the inside, has the numbers listed below frost will appear again under those conditions.

a temperature of 60F or 15.5 C

a RH of 35 percent

a DP of 31F or -0.555 C

HomeSealed 02-13-2014 08:45 PM

Vacuum? The aluminum window leaks air like a sieve, beside the fact that it is extremely conductive. There need not be a sealed air space between, the key is sealing the window off from interior moisture, OR sealing and insulating from the exterior cold. As WoW stated, rigid XPS combined with caulk or expanding foam for seal will do the trick quite well. It can be done from interior OR exterior to reach the desired end... Probably does not matter ultimately, as it sounds like the OP is open to replacement, which is the best solution anyway.

oberon 02-14-2014 07:08 AM

[QUOTE=Fairview;1306061]
Quote:

Originally Posted by HomeSealed (Post 1306002)
If it is sealed from the inside, interior moisture will not get to it, so no frost. Blocking off from the outside is fine though too.
As joe said, the window is not load bearing and can be cut out for replacement. Vinyl and glass block are probably the most common replacement options.[/QUOTE
***********************************************

You are correct "If it is sealed" and you forgot the vacuum part.

Now tell us how a home owner or contractor is going to vacuum that space, as double pane windows are made, using a low conductive gas such as Argon to bring the dew point temperature down in the -35F range.

It ain't going to happen.

I am confused, vacuum what space?

oberon 02-14-2014 07:12 AM

Quote:

Originally Posted by Fairview (Post 1306165)
Whatever benefits the OP but he/she should understand that for example:

If when the air present at the window, when it is ( perfectly ) pre - sealed sealed from the outside and insulated and ( perfectly ) sealed on the inside, has the numbers listed below frost will appear again under those conditions.

a temperature of 60F or 15.5 C

a RH of 35 percent

a DP of 31F or -0.555 C

Sorry, but I am even more confused now. Would you mind going a bit more in depth on this?

SeniorSitizen 02-14-2014 10:47 AM

Quote:

Originally Posted by oberon (Post 1306559)
Sorry, but I am even more confused now. Would you mind going a bit more in depth on this?

Use the link to solve for any of the three conditions by clicking in the dot and running the bars.

http://dpcalc.org/

We were only given the relative humidity in the room so I'm just picking a number for temperature and chose 60F.

If the room temperature is 60 with a relative humidity ( RH ) of 25 percent the window frames will condense moisture beginning at 25 and in this instance it will be ice as we see when we solve for DP ( dew point ). So we know without a doubt the frame temps.are 25 or below, possibly much below.

Now using the link solve for RH by raising the DP temperature to 40F we see that we could raise the RH to 45 percent before condensation would occur on the metal frames with the same room temperature.

If the cold air is prevented from reaching the metal frames and the interior of the living area by blocking it with outside insulation the heating bill will be reduced some and one or more of the de-humidifiers may be turned off, possibly both.

oberon 02-15-2014 10:03 AM

Quote:

Originally Posted by Fairview (Post 1306656)
Use the link to solve for any of the three conditions by clicking in the dot and running the bars.

http://dpcalc.org/

We were only given the relative humidity in the room so I'm just picking a number for temperature and chose 60F.

If the room temperature is 60 with a relative humidity ( RH ) of 25 percent the window frames will condense moisture beginning at 25 and in this instance it will be ice as we see when we solve for DP ( dew point ). So we know without a doubt the frame temps.are 25 or below, possibly much below.

Now using the link solve for RH by raising the DP temperature to 40F we see that we could raise the RH to 45 percent before condensation would occur on the metal frames with the same room temperature.

If the cold air is prevented from reaching the metal frames and the interior of the living area by blocking it with outside insulation the heating bill will be reduced some and one or more of the de-humidifiers may be turned off, possibly both.

Thanks for the reply and the explanation.

When I read your two posts in the morning as I was about to head off to work. I was a bit pressed for time and on reading your posts I was a little confused about what you had said - my fault - I should have waited until later and a more leisurely reread before replying.

When you mentioned "...and you forgot the vacuum part.", were you referring to vacuum glazing? That's what I was asking about in my first not-so-clear reply.

Per my second post, thank you for the reply and the link to the dew point, temperature, relative humidity calculator. Actually I already have that one in my favorites (I think I got it originally from WoW as I recall?), anyway, it is really handy for quick calculations when you have two of the variables, but it really isn't very clear on the physical concepts involved and it can be misleading - but and frankly it probably isn't really that important for a discussion like this one. However, since I am a nerd and I find the concepts fascinating and I think this type of discussion is fun, I am going to wander into it anyway (sorry all).

Dew point is defined as saturation vapor density or simply 100% relative humidity. Dew point is determined by the amount of moisture in the air and it is independent of the temperature of the air. This is where I think that the calculator can be confusing, because someone who uses it without understanding the concept might come to the conclusion that it is possible to adjust the dew point by changing room air temperature, or changing relative humidity, when in reality the dew point is completely independent of temperature changes and relative humidity is based on the dew point not visa versa-.

Relative humidity, on the other hand, is totally dependent on temperature. Probably why it's called relative. Increase room air temperature and the relative humidity drops. Lower room temperature and the relative humidity goes up. But in either case the dew point doesn't change, it is unaffected by the changes in in either air temperature and relative humidity. Which makes perfect sense when thinking of the dew point as the "pivot" that drives the "relative" part of relative humidity.

Although we certainly feel and react to the relative humidity of a space that we occupy, windows really don't care what the Rh is at all. Windows (and metal drink containers and metal frames and so on) only worry about whether or not they are above or below the dew point temperature. Above dew point means evaporation of any moisture on the surface and below dew point means condensation on the surface. Need to change the dew point? Add moisture to the air and it goes up. Take away moisture and dew point goes down.


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