Condensation a sign of need to replace?

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deborah
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Location: toronto ontario

Condensation a sign of need to replace?

#1 Post by deborah »

Here is a dumb question. I have older aluminum sliders in parts of my house. When it gets really cold out and I see condensation and then icing on the insides of the windows,does that mean I should replace these windows. I've looked around the neighbourhood and lots of houses have this-I assume it means air is leaking. But does it also mean it's making the house really cold.

I have an old house-1925- and it is always freezing in the winter. Is it the windows. It's not insulated in parts- you all know old houses-but I"m wondering how much the windows contribute. I changed my kitchen windows to double hung Peach Tree and it's still freezing and drafty there-and it's the renovated part of the house. So, I'm wondering if the windows make a difference or not.

thanks for any insights.

WindDoze
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#2 Post by WindDoze »

You didn't mention what part of the country you lived in, but the reason you are getting the condenation and ice is that the aluminum windows in your home are conducting the cold from the outside to the inside of your home. The humidity in the house is condensing (and freezing) at the coldest point -- on the aluminum. Aluminum windows have no insulative value at all and generally speaking shouldn't be used unless you live in a warm climate. The fact that you say you are getting ice on the windows leads me to believe that you don't live in the south...so yes replacing the windows with a good quality, vinyl window with a good thermal pane should help....assuming its installed correctly. (Tipping my hat to all the great installers on this board.)

deborah
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Location: toronto ontario

why aluminum?

#3 Post by deborah »

Live in the deep freeze of Canada. And strangely in this neighbourhood, most of the older homes, if they have removed the original wood windows, replaced them years ago with aluminum. Must have been the thing to do in the sixties. So, given what you have said, can vinyl make a big diff in terms of coldness in house? I don't feel any drafts from these windows and, as I said,my kitchen is still freezing. So, given that this is an investment of about $6000, will I notice a difference? Know you can't guarantee having never seen my situation, but would like to know what you all think.

thanks from Toronto.

WindDoze
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#4 Post by WindDoze »

I'm in MN, so I know a little bit about the deep freeze. The crooks at Pacesetter came through here back in the 70's and put a lot of aluminum windows in people's homes that didn't know any better. I can say with 100% certainty that a vinyl window will make a difference. Drafts or not -- your house is cold because of the cold being conducted through the frames. Based on where you are I'd highly recommend a triple pane window as well. I don't know what's available in Toronto -- if you can get a Schuco, or Simonton 9800, or other top line triple pane window you wouldn't regret it.

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Window4U (IL)
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#5 Post by Window4U (IL) »

The first 15,000 windows I installed in my career back in the 70's were NuSash aluminum windows. They were ggggggreat.

Sorry about that. All the g's were me shivering when I thought back about those windows. What I meant to say was that they were great at keeping a twelve pack cold on the window sill.

deborah
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#6 Post by deborah »

Window 4 U- You made me laugh- not easy to do at midnight after a long, long day!! Thanks

deborah

Guy
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#7 Post by Guy »

Unfortunately Pacesetter is still terrorizing the land today as we speak. They are just using vinyl instead.
Your condensation issues may not be the windows. More than likely your windows are playing a roll in the issue. Your problem is "Air Infiltration". This is a commonly blamed on the window. Since you've already had a window replaced and still need to scrape the windows and wear your coat indoors. It points to a couple things making your condensation. First of all your wall insulation was probably nothing more than an old 1920's wedding dress. You may need to upgrade. You may also find your windows were replaced without proper insulation around them. So cold air is coming in for a cup of tea!! Since I also live in MN as Windoze does. I also understand a little frost on my chin while I sleep. I however sleep better in a snow bank than a hot beach. Your a perfect candidate for an Home Energy Analysis. If you were here in MN we could have you figured out tomorrow. We use a blower door to de-pressurize your home and search for the unwelcome guests. With todays Building Sciences we find all these little (or big) issues and let you know what you can do to fix them. Take some time to check with your local Energy Provider to see if yours can be done for free. It's well worth the time!! Good Luck!!

deborah
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Location: toronto ontario

#8 Post by deborah »

Thanks Guy- and I agree with your points. Had an energy audit done in October and that caused me to replace one window, which was the worst offender. My new kitchen windows were leaking and I called in the company-who didn't believe me and fiercely resisted coming by. I had to use the threat of small claims court to get the owner to come over and look-and sure enough. There are some problems-some of which may not be fully resolvable.

So, yes it's a leaky house. And it's a big deal to insulate where none was. However, the kitchen is a new reno and supposedly well-insulated and it's the coldest room in the house. So, go figure. The energy guy thinks it 's the floor- non heated linoleum etc. But most floors aren't heated-that is a very new trend here-and the rooms aren't as cold as mine are.

So, i sit here bundled up and feeling chilled. House temp is 19 C which shd be ok but always feels colder than it really is. Did some fixes for drafts and still cold.

So, appreciate the perspective. Searching for solutions. BTW-not scraping condensation off the new windows-only the old aluminums.

WindDoze
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#9 Post by WindDoze »

Its the windows, its the windows, its the windows. Aluminum is a conductor. Its great for keeping things cold...that's why beer cans are made out of it. It sucks as an insulator. With all due respect to Guy, even if your windows were packed with insulation all the way around, installed absolutely perfectly and had zero air infiltration they still would have ice on them on a cold day.

HipKat
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#10 Post by HipKat »

That is the truth. I always ask people what they use to scrape the ice off, so they can see the kids get on the bus in them orning.
Anderson put outa broucure a while back labelle "understanding condensation" and in it they wrote that aluminum is a sof metal that is highly conductive. it will conduct the cold from outside to inside. Glass has no insulative quality in itself, so once the frames get cold, the glass gets cold, then the cold from outside emenates in and whammo! Heat transfer; the heat goes out.

Guy
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#11 Post by Guy »

Windoze & Hipkat, You need to spend some time with someone in building sciences. You both are stuck in that "Blame it on the windows" sales tactic. Your both educated salesman in your companies. Windoze happens to also be an owner. You both need to spend some time learning what causes ice build up. It's not just the windows!!!! There's more to it than that. These are the comments and thoughts we are trying to fight when it comes to our trade. Most aluminum windows made in Canada were required to have a thermal break since the mid seventies. Not that they all complied, but Canada is a little bit more advanced in cold climate windows, than we are. Even us arctic dwellers here in MN are a step behind our Northern Ice Barons. If you don't educate yourself in this part of our industry. You'll be so far behind it will take you years to catch up.

Hipkat: I know your young and soaking up knowledge like a sponge. So take some time to research some of these things.

Windoze: as an owner of one of the fastest growing exterior companies in MN. I know first hand you didn't get there by being a crook. You have always strived at being on top the ladder with the most advanced technologies available in the industry. If your still saying the windows are the culprit your behind in your technology.

As for the moisture and ice. Here goes, relative humidity is called "relative" for a reason. It is a comparison of the amount of moisture in your air vs the temperature of the air. We know that warm air can carry much more moisture than can cool air. When air is at the temperature where it reaches 100% saturation. The air must begin to release moisture. like fog rain etc, 100% saturation and 100% relative humidity really mean the same thing. So when your relative humidity reaches 100% it is also known as the "Dew Point". This is a term most of us hate to hear in MN with those muggy Summer nights.

I keep my house around 68 degrees during the day. My air can hold 17.4 grams of moisture (dew point) for every meter of air if it's 100% saturated. If I have that much moisture then I will have 100% relative humidity in my home. now if I raise the temperature to 76 degrees it will fall to 78%. So now I have a higher temperature with the same amount of moisture. FeneX always tells us that Heat always travels to cold and wet always travels to dry. In our Winter months, the outside air is cold and dry. Our inside air is warm and moist. That warm and moist inside air wants very badly to equalize with the cool dry outside air, so it is looking for a way to get outside with the kids. So now we use our Building Sciences that revolve around Physics. Since your windows are cold and old. They don't have any kind of thermal advantages as todays windows do. Your cold uninsulated walls around these windows that are leaking air everywhere feed the fire. This cold uninsulated area is like an open invitation for your nice warm inside air to try and get outside The warm air is contacting that window and, like an ice cold beer from the refrigerator, that window surface is below the dew point of the air inside your home...thus, condensation on the glass or frame surface.

Now if you cut your air infiltration down and insulate some walls. You will be on your way. Testing your HVAC system will also control a ton of infiltration issues. Your system may not have enough air flow to properly circulate the house and keep the windows clear of moisture. Now I did say above in my first post the the windows do contribute to the issues. I would look into replacing them soon. But I can guarantee you if you only replace the windows and do nothing else. You'll have moisture on your glass like your new window in the kitchen!!

I would like to credit FeneX and Oberon on this post as it's their teachings over the past four years that brought me this knowledge. Thank You!!

Guy

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Window4U (IL)
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#12 Post by Window4U (IL) »

-
Oberon once had a great post about this.(like usual) Here it is:



[Oberon quote]
The reason why there is condensation on the interior of your windows has a really simple explanation – the surface temperature of the window is below the dew point temperature of the air in your home…that’s it…a very simple explanation.

Unfortunately, the reason that the window surface temperature is below the dew point temperature can potentially become somewhat more complex, but I am going to offer a few thoughts and even throw in a few numbers that I hope might help your situation.

In the summer, when you pull something cold and refreshing out of the refrigerator, and the air is warm and humid, that cold and refreshing beverage container suddenly and quite magically becomes instantly wet – just as soon as it is exposed to the air. What has happened is that the temperature of the container fresh from the refrigerator is below the dew point temperature of the air – which has caused condensation on the outside of that container.

What happens to your windows in the fall and winter is that the surface of the glass is below the dew point temperature of the air in your home – which is causing condensation on the surface of that glass.

Dew point is defined as saturation vapor density...or put in simpler terms, when the air reaches 100% relative humidity and can hold no more moisture.

Relative humidity is, well, relative.

Relative humidity is a comparison of the actual vapor density versus the saturation vapor density at a particular temperature. Put a bit more simply, dew point is 100% relative humidity or the point where the air - at that temperature - is no longer able to hold any more moisture. If the air has reached vapor saturation (100% relative humidity), then the air will release moisture...be it on the outside of that cold beverage container in the summer time, or be it on the interior glass surface of your windows in the winter time, it makes no difference. If the surface temperature happens to be below freezing, then that moisture becomes frost or even ice.

In order to stop condensation from forming on the surface of a window, you either have to lower the dew point temperature of the air in your home to a level below the dew point temperature of the window surface, or you have to warm up the window surface to a temperature above the dew point temperature of your home, or a combination of both.

Lowering the relative humidity of the air in your home MAY have absolutely no effect on controlling window condensation…and I bet that that statement is a bit of a surprise to some folks…it is true however because there are two ways to lower relative humidity – increase air temperature or decrease moisture content. If you increase the air temperature you will lower the relative humidity but you will not change the dew point - which is based on the amount of water vapor in the air and is not based on the temperature of the air.

The amount of moisture in the air is measured in grams per cubic meter, which is kind of nice for our metric folks but not so nice for our non-metric folks; but the metric version is much easier on the calculator than the English version. However, in the interest of making this stuff easier to understand for all of us non-metric types, I am going to use Fahrenheit rather than Celsius temperatures in the calculations.

Okay – consider your home at 65 degrees F and with a relative humidity reading of 40%. There are 6.25 grams of water in a cubic meter of air in your home in that particular scenario - which then equates to a dew point temperature of 38 degrees F. So at 38 degrees the air will be at 100% relative humidity or at saturation vapor density.

Now, if your neighbor keeps her house at 75 degrees, but she also has 6.25 grams of water per cubic meter in her air, then the relative humidity in her home is 29% - versus your 40%. But, and here’s the kicker, the dew point temperature in her home is still 38 degrees.

While the relative humidity in her home is much lower than is the relative humidity in yours; if the surface temperature of the windows in her home is 35 degrees she will have condensation on those windows…yet if the surface temperature of your windows is 40 degrees – only five degrees warmer – you will not have condensation on your windows.

So, while her handy humidity gauge reads (correctly) only 29% RH – she has a condensation problem.
While your handy humidity gauge reads (correctly) 40% RH – you don’t have a condensation problem…SWEET…well, for you anyway, not her.

If your home hygrometer measures the relative humidity in your home at 60% while the temperature of your home is 70 degrees, you will have a dew point temperature of about 51 degrees – meaning that if the temperature of the window surface is below 51 degrees then you will have condensation - so now we talk a little more specifically about windows.

The interior surface temperature of a single lite of glass, when the temperature outside is 0 degrees F and the inside air temperature is 70 degrees, will be about 16 degrees.

Add a storm window on the outside and the surface temperature of the inside lite jumps up to about 43 degrees – a huge improvement.

But these are center-of-glass readings and not the temperature readings at the edge of the window where condensation usually forms. A typical clear glass dual pane window is going to have center-of-glass temperature reading pretty much the same as a single pane with a storm – something that is often claimed (correctly) by folks who advocate refurbishing windows rather than replacing (something that I am not going into here – I am NOT advocating either replacement or restoration in this post. It is long enough and detailed enough already without opening that particular can-of-worms!)…

However, if that dual pane has a LowE coating and an argon gas infill then the center-of-glass temperature will be about 57 degrees – a 14 degree improvement over a clear glass dual pane or a single pane with storm window – but again, and more importantly, there will be a comparable edge of glass improvement as well, particularly if the IGU (Insulating Glass Unit) was manufactured using a warm edge spacer system. Also, the dual pane is going to have desiccant between the glass layers. Desiccant absorbs moisture keeping the inside of the dual pane system very dry.

The advantage? If it gets cold enough outside, the temperature in the airspace between the lites can get very low. By keeping that space dry, it helps to keep the dew point temperature very low as well; something not always possible when using a single pane and storm window.

Although a single pane with a good and tight storm window can help the interior lite to avoid condensation (when compared with a single lite and no storm), the storm window itself will frost up when the temperature is low enough – at a temperature usually well above the temperature that will cause the dual pane to ice up. It is unavoidable given the right circumstances

So what does a window temperature of 57 degrees mean? Well, as I mentioned earlier a home kept at 70 degrees with a 60% relative humidity has a dew point temperature of 51 degrees so it is unlikely that there will be condensation problem on those particular windows despite the relatively high relative humidity in the home.

But what happens to the dew point if you keep your home at 70 degrees and you have a 65% relative humidity? Well, for one thing the dew point has jumped up to 57 degrees which we have already noted is the same as the window temperature. For another thing, anyone with 65% relative humidity in a home at 70 degrees has way too much moisture in their air and they are in serious need of some sort of ventilation system – or at least several good exhaust fans!

Somewhere back in this post I mentioned that lowering the relative humidity in your home may not help control condensation…that is still true…IF the relative humidity is lowered because of an increase in temperature. But, lowering the relative humidity by removing water is a different story because in that case you will also be lowering the dew point as you lower the relative humidity and that WILL help to control condensation on your windows.[/quote]

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