Window Condensaton Redux

Hi, Chris.

Such condensation indicates that the air next the window has dropped below its dew-point. You probably know that. :')

My bet is that the windows are sufficiently conductive that the temps drop enough to ... you know the rest. If you don't have storm windows, they will help, as will plastic film inside, to reduce heat loss. There are sealing & insulating curtains that work well, but might not be to your taste; with such, the inside of the glass would be colder yet, but at least isolated from inside airflow.

What is the allleged r-value of the windows? What are your options for replacing them with something less lossy?

Good Luck, J

Chrisotpher H. Laco wrote:

hey - I just came across this. Has some good tips.

"My last conversation with Pella ended with them wanting $150 for someone to come out and inspect the windows. Maybe it's time to get it from the

horses mouth. Most of the stories I've heard end up with "the were installed wrong. tough luck for you".

Glad I have Anderson, though I don't know if they would come out and take a look without a charge either. How old are these windows? I would hope that if this were reported back to Pella within the first year or so that they would send a rep to look at them for free. In any case, if they won't come for free, at this point, if I were you, I would pay the $150, and start with Pella, as one would think they would be one of the best sources for problems with their own product.

You probably have a tight well-insulated house with a good qty of insulation in/above the ceiling. What has probably happened is that when the insulation in the attic/ceiling was laid, it covered up the eaves thereby blocking passage of air in the attic. Check this & ensure that you have good circulation in your attic that removes all moist air with good cool dry outside air. I feel comfortable in saying that this will solve the condition. Ashoke - heating.products.bz

Pella condense quicker-at higher humidities than other glass, go online Consumer Reports they have an extensive old rightup, a good article.

You humidity needs to be acuratly monitored, analog humidistats need to be calibrated and 99% at stores are 10-20% off New and can`t be calibrated. Get a few digital units and learn what your humidity is, possibly a window lost its argon but doughtfull,

Call Pella they are under warranty Your new house is tight new construction? with Tyvek? Possibly an air exchanger is needed a blower door test apx 300$ will determine it.

Well of course you keep doors closed and no air circulates, Open Them.

Get a few pros out, we are not there.

In fall when heating season starts indoor humidities are higher before you dry out,

Get a dehumidifier, and learn Your House, high humidity will ruin the pellas wood, the Poly was not bad but your letting this occur continualy will ruin all your finishes and Pellas .

If these are casements that are single pane with a added removable second pane then they are not true double pane glass, they have no gas inbetween, air seal, or E coating. Their R value is probably 2, vs 3.3 for sealed dual pane, and R1 for single glass. If they open then pella probably has Tri pane replacement sizes. I dought leaking would make matters worse as it will equalise interior air vs outside temps near the window, Therefore a leaking glass would condense Less.

I've oft wondered if this was accurate thought. These windows are big, and the coldness of the glass alone would make the temp next to them drop, even with no draft or leakage, I would think.

My last conversation with Pella ended with them wanting $150 for someone to come out and inspect the windows. Maybe it's time to get it from the horses mouth. Most of the stories I've heard end up with "the were installed wrong. tough luck for you".

I've got vents in both bathrooms, and I've tried cracking the windows when I shower. I've even tried a humidifier without much luck.

Cheapest solution first..a little foam to test a theory.

Thanks,

-=Chris

:-)

By leaving doors open I meant interior doors, where you keep pets.

You dont state at what exterior temps you have 20-25%. I have Pellas and the same BS issues, My Andersons do not condense but all my glass is sealed dual pane Low E Argon. Im Zone 5 Chicago area. If you have nonsealed, non argon, then yes they are even worse than sealed glass.

Poly should be UV resistant, exterior grade is UV resistant.

:-)

I've always wondered about those casements. Double-pane removable in the intior..and the vent holes between th exterior pane and the outside cold world...

As soon as I win the lotto. I've got 12 of the huge casements, and 4 of the halfsize casements. If I'm going to spend that kind of money, might as well let them cook for a few more years.

The funny thing is, my vinyl clad double hung aluminums in the basement never condense, and it's about the same temp/humidity down there right now. Actually, the barely sweat, right in the corners where the foam is probably not so tight.

-=Chris

Got 3 Oregon Scientifics humming along. I'd say they're as accurate as the local weather staton as they usual line up (the outside one that is).

No clue since I'm not the original owner. I've had to HVAC people tell me an exchanger would not solve my situation.

Well, there's one door; no storm door. That won't work. :-)

The problem is finding them locally that know anything. They all have theories, and most of them don't line up with an exact "do thins and it will be solved".

Indeed. But like I said, I have the same problem mid season with %20-%25 humidity indoors.

Tried it three times, two different units in two different rooms. It made no difference other than noice and heat.

I don't agree 100%. A good UB rated poly would not peel between the windows, on the inside frame where it not exposed to direct wetness. It's all sun wear.

You might look for and try to fix any large water vapor sources, eg a damp basement floor or walls or a rainwater leak. If you have no major water vapor sources, you may have a fairly airtight house, which is good :-) In many US houses (those requiring winter humidification), air leaks account for more than half the fuel bills. If your house has any exhaust fans, you might turn one on with a humidistat when the indoor RH rises to 50% in wintertime.

That is strange. Perhaps you are measuring incorrectly. The dew point of 20% RH 70 F (530 R) air is roughly 530/(1+530ln(0.2)/9621) = 487 R, ie

Where? If the air pressure inside the house is lower than the air pressure outside, outside air would enter the house. If the outside air is cold, it probably contains less moisture than the air inside the house, so it would have a drying effect. Same effect with windows that leak lots of air.

Your HVAC guy may have been clueless.

Nick

I know this is a timeless topic that never seems to die, but it's that time of year where my windows drive me insane again.

The house was built in 1997 with Pella Architect casement windows and extra insulation in the attic, and I'd also place money on the furnace being undersized. To add insult to injury, when the contracters installed the ductwork, they made the mistake of routing one floor register vent into the cold air intake box.

This is the third year I've lived in this house, and fighing window condensation seems to be a yearly obsession of mine. If wouldn't give a rats patute about the condensation if it weren't for the fact that if starts to run, and freezes on the seals and on the wood itself.

Right now, my humidity is high (50%), but I have the same problem with condensation at %20-25. It starts with the two bedrooms and master bath upstairs, but eventually, it makes its way to all of them. Now, those two rooms and that bath have their doors closed all of the time due to pets. I'm sure that's not helping air flow either.

Here's what's happened so far:

The end of last season, I have a local HVAC guy stop buy. His take: negative pressure. He also pointed out that the AC fan was wired to HIGH, and the Heat fan was wired to LOW. I promply set the heat fan to MEDIUM, and that appeared to make a difference during the last month of winter (Ohio winter). But, since we didn't have many bad days by then, maybe that was a fluke.

As usual, I've cleaned all of the frames to get out the webs, nests, dirt, grass, etc. I've clean all the weap holes, and I've put a new coat of UV rates poly on the wood frame between the outer pane and the inner removable doublepane so they're not sucking mosture. The poly they used when the house was new was clearly not UV rated since it was peeling like crazy. But I digress...

Here it is, October 17, at ~40 outside, and the fun has already started with condensation for the first time this morning. The house usually sits around ~65F and I haven't turned the gas furnace on yet.

We just ordered glass doors for our wood burning fireplace insert with the plans of burning much more wood this season due to the skyrocketing gas prices. The insert has an outside air source vent, and a blower to blow the box air back into the house. With any luck, the glass doors will do their job and keep the heat I have in the house. :-)

I also turned the furnace fan on this morning just to help with circulation. Who knows if it will make any difference.

While cleaning the windows, I've taken notice of the fact that the rubber seals they put on those things suck serious butt. In some cases, the seal is so flat, it can't be sealing against the wood frame well, if at all. Combine that with negative pressure, and you have a real good time.

I'm toying with the idea of getting some thin weatherstripping, and trying on of the problem windows to see if that helps.

They are plenty of directions to go from here, but I can't seem to find anyone local who really knows their stuff. Any thoughts?

-=Chris

Well so far chris you dont indicate or show a true knowledge of what you even have in glass, you say dual pane removable which would be R 2. So it all might be normal.

Most of the Ohio winter when I see 20-25 humidity, it's the usual 0-40 outside.

That's what I finally put on. A nice UV outdoor poly rated for (of all things) window jams, frames, etc.

The removable inner part is two panes together, at least it looks that way. It's certainly much heavier and thicker than a single pane piece of glass.

And I appreciate the help. Don't get me wrong. But this is my problem thus far. Oddles of opinions, but no experts in town to actually say with confidence, this is it. :-)

I think that you spent 10 paragraphs talking about your windows, and the only parts of it that even resembled useful information was "Humidity is around 50%", "The seals might not be good".

The bottom line is, you have two possible approaches, either keep the water(humid air) away from the windows, or make the window surfaces warmer.

Have you checked for actual air leaks? Is this condensation over the entire window, or just on parts? Which parts? Are you sure that what you're getting isn't water-leaks in the wall around the window?

Put a clear plastic seal over the entire window, and see if it moves when the wind blows. Put dessicant between the clear film and the window, and that should solve the wetness issue, because that will keep the WET and COLD separated.

Moving your hot-air supply directly in front of the window or aiming a heat-lamp at them would probably also work, by heating the window surfaces above the dew-point.

--Goedjn

My basement is dry as a bone. Thank god. My last house didn't have that luxury. :-)

Perhaps. My only "measure" is ye old Oregon Scienticis sensorys with the RH sensor. Eve it it's wrong, it's still relative to itself (%50 down to %25)

Funny. Just this morning, the outside RH was higher than the inside RH, using two of the same sensors. All tings being equal..

Quite possible. The more of them I try, the less help I seem to get past wanting to sell me a new unit with a variable speed fan. :-/

Sire I don't. I don't make windows, nor did I purchase the initial windows to know what their specs are. All I can say is what I see. THe internal removable pane is twice as thick as a normal pice of glass.