Condensation on Inside of Storm Windows. Help!

Finally I get to post to Breaktime about something other than the forum technology… I live in a 1950s house that was originally built as a small summer lake cabin and then over the years was added on to by someone who I suspect was an intoxicated summer vacationer who didn’t own a square, not a builder. Every winter when I wake up in the morning nearly every storm window is frosted over on the inside. These are old storm windows and probably leak a lot of air. I suspect this is not good. But how not good is it? Do I just need new windows or is there a bigger problem with moisture going on? Thanks! Matt
Replies
Matt, the warm moist air from iside of your house is condensing on the cold surface of those storm windows. That is what happens when warm moist air hits a cold surface. Think cold bottle of beer in the summer.
Perhaps the air inside this structure is too humid. I would say around 40 to 45% at this time of year? Cold Northeast? Do you know what the humidity is inside the home? Perhaps you have a dirt crawlspace or basement?
Obviously, there is conditioned air ( the air inside the home that you paid to heat or cool) reaching the storm windows, so that of itself is not the best scenario.
On any count, if you have windows with the old triple track storms it's time for and upgrade most likely. I remember when we were kids we would scratch drawings into the frost!
Glad you could catch a break from the chaos this place has become.
Eric
thanks for the quick reply. I live in connecticut and it is very cold and dry out right now. And I do have a basement, though its more like a slab foundation with earth on one side because we live on the side of a hill.
I'll have to check the inside humidity. But now that you mention it , I suspect I know one potential cause. We run a woodstove during the day and it gets really dry so my wife runs a vaporizer. When the fire goes out over night the vaporizer doesn't and it must fill the house with excess moisture. One other thought: I put new windows in the basement and added insulation to some of the walls down there so all the moisture from the basement is probably going right up stairs...
You could probably add an interior storm window of plexiglass and solve the air leak problems as well as vastly improve the efficiency of those windows without replacing them. Pretty easy plans can be found on line.
MBerger wrote:"I live in connecticut and it is very cold and dry out right now. And I do have a basement, though its more like a slab foundation with earth on one side because we live on the side of a hill."
Matt, if you have exposed earth in your basement you need to cover it as well as you can with poly. Probably no vapor barrier under the slab either.
I'm not exactly sure what your specific concern is with all of this........the frost?.........crappy windows?
Matt,
You need to replace the weatherstripping on the windows.
For now, just get some of that "rope caulk", and press it into the crack all around the window sashes. Peel it off in the spring, and make sure you replace all the weatherstripping in the spring or summer.
Or, alternatively, get some of the clear stretch plastic "inner storms" that someone else mentioned. (You still need to replace the weatherstripping in the spring or summer.)
As for the humidifier...
Stop using that.
If the concern is dry air because of the woodstove...
Make the woodstove, itself, cure the problem.
Put a pan of water on top of it.
When the fire goes out, the pot of water doesn't go on adding the amount of moisture to the air, that the humidifier does...
They make cast iron "pots" just for this purpose.
Matt, do you have and use exhaust fans in the kitchen and bathroom(s)? A huge amount of moisture is generated while you're taking a shower and it's best to get rid of it at the source.
Matt, as has already been stated-the fact the storms show frost means moist air is between the interior glass and the storm. Higher than "normal" interior humidity levels or not, there's air leakage from the prime sash. Seal that up and you might still be able to be comfortable inside with no frost on the storms.
My only reason to answer was to get this in the post thinking you might read this sooner than the Matt Berger/Ed Pirnik thread.
new
Submitted by calvin on Wed, 12/30/2009 - 18:14.
If you can send me a link to a particular post with missing images I can track them down.
http://forums.finehomebuilding.com/node/128903
Here you go Matt. This was a few yr old thread that had some pretty nice photo's included as both imbedded and linked. That I started it has me really concerned about it's past and potential future. I asked you folks early on about it and didn't get any kind of reply-generic or specific. So there you have it. Any answer?
thanks
No one said anything specific about the moisture between the sash and the storm. But, by the same token, he didn't tell us where the storm window was ... inside or out.
storms are on the outside.
Matt,
You had an initial picture in the Gallery that I think I remember showing a flashing/siding/moisture issue. Was there one of these windows in that area? (assuming my memory is somewhere close......)
picture from this morning...
If so, your windows are pretty leaky. Does this only happen on one side/area of the house? If everywhere, your house is overpressurized (e.g. w/ an imbalance of a heating system fan).
This does not necessarily mean that the moisture level is too high in the house.
What it means is that air (moisture) is moving through windows faster than it can move out past the storms.
Storm windows are suppose to have weep holes at the bottom. This will be one or two 1/8 to 1/4" holes or notches.
Often this will get caulked and painted over.
The other thing is that the weatherstripping on the windows might need fixing.
If the interior humidity was too high you would be having condensation on the inside of the windows.
You're assuming the storms
You're assuming the storms are on the outside ... may or may not be the case.
Looks like some clarification needed. Where are the storms ... on the outside of the window or the inside?
If storms on the outside, this means a leaky window. Frost would normally form on the inner most pane of glass on a cold day.
But you are beginning to see the issue w/ your vaprizer running ... that can easily cause condensation ... but I still agree w/ Bill H. - high humidity would mean condensation/frost on the inner most pane of glass. Frost between means a lot of air leakage around the window and not [relatively speaking] around the storm ... assuming storm on the exterior. Always good idea to assess moisture generation and the ways you are getting rid of moisture ... do you have exhaust fans in bath and kitchen that positively connect to the outside (not just dump in the attic)?
And I suppose you can ask him if this is his first winter there.
What you describe is reasonably normal, and, while not "good", is not a serious problem. You want to make sure that the weep holes at the bottom of the storms are open so any condensation can drain out (vs causing rot), but if that's taken care of, and the condensation isn't extraordinarily bad, it's nothing to lose sleep over.
The simplest fix is to buy the 3M heat-shrink plastic film you apply over the inside of your windows with double-stick tape. It takes a little time to install, but it's reasonably cheap and will both solve the condensation problem and make the place more comfortable.