Hi, If I'm understanding you, you will need to remove the glass, remove any other debris from the joint (paint, putty, crud) and clamp the sash back so that the open joint is tight again; apply some glue to the joint. The problem you could run into is that with the glass removed, you may lose the reference to squareness which will later affect how the sash fits. If possible, the glue-up would be done with the unglazed sash temporarily reinstalled and shimmed into the opening. It would then just be a matter of replacing the glass and repainting the sash. If this casement has interlocking metal weatherstripping, you'll have to make sure that it is in good kit as well. Casey

I am also having the same issue about condensation. I am also running out of solutions and would like more options for resolving the problem. I live in southern Ontario. We experience extreme temperature differences in both the summer and winter. Some of my windows were installed in 1994 and some in 2004. To be clear I have the triple pane system which includes a sealed double pane window with a removable 3rd panel. I have the Pella blinds between the sealed double pane portion and the removable pane. The condensation is occurring between the sealed unit and the removable panel. I do not have condensation in the sealed double pane portion of the window. The condensation problem only occurs in the summertime. Pella explains that you must keep the breather (vent) holes clean. The original post by Bsman36 refers to how the breather holes are kept faithfully clear to allow for moisture to get out, but the moisture remains. SusanM05 also referenced in the original post also refers to this. I have several questions; 1. My vent holes appear to be clean on the inside. But when I try to slip a wire through the vent holes the wire does not go through to the outside; so how do you know if the vent holes are clean. The vent holes do not appear to be accessible from the outside. Another owner of Pella windows explained to me that he uses an air compressor to clean out the vent holes to get around the corners. I will try this but how do you know if the vent holes are in fact clean? 2. Another suggestion made was that the wood frame may be absorbing the moisture and then re releasing the moisture back into the space between the glass panels when there is a temperature/humidity difference; but if this is the case does it make sense that I would only have the problem in the summertime and not in the extreme winters? 3. In an old ownerâÂÂs manual the following statement is made on how to eliminate summertime condensation between the Pella glass designer series. â Between the glass condensation may occur on the exterior of the hinge glass panel if the inside ear is very cool as a result of air-conditioning and humidity outside is extremely high. If this weather condition is not temporary plug the breather holes for the summer season or raise the indoor temperature. Contact the Pella Window and Door store nearest you for a set of Pella breather hole plugs.â Has anyone had any success resolving this problem with the use of the breather plugs? This is the opposite of keeping the breather holes clear; but, this solution is only is only to be used If this weather condition is not temporary. I am not sure how practical this solution is as the temperatures fluctuates daily.The problem is worst on days of extreme temperatures/humidity differences inside the house and outside.

Okay, this is a really long answer. I have posted this same answer to this same question previously - but it is a really good question and it becomes a common question this time of year... The reason that you have moisture on the inside surface of your windows is because the temperature of the glass is below the dew point temperature of the air in your home. In order to stop moisture from forming on the surface of your windows, you either have to raise the temperature of the glass to a level above the dew point temperature of the air in your home, or else you have to lower the dew point temperature of the air to a level below the temperature of the window. Unfortunately, suggesting those two solutions is often much easier than actually being able to accomplish either one. I am going to include a post about window condensation that I wrote and posted on a different forum in THS. It is really long and even has a little math in it...but I think it does an okay job of explaining some real basic information about window condensation. -------------Window condensation -------------- 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 homeÂthatÂs itÂa 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. Basically, 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 condensationÂand I bet that that statement is a bit of a surprise to some folksÂit is true however. 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 hereÂs 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 windowsÂyet 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 donÂt have a condensation problemÂSWEETÂwell, 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 condensationÂthat is still trueÂIF 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. I hope that made sense...please feel free to question anything that I didn't explain well...

WoW, If that is true you assume the seals in your hypothetical window are still "perfect" at 30 years. Very questionable. Further, U value is mainly important in northern climates while SHGC is much more important in southern climates. Modern films can also often be applied to single pane windows to bring many performance factors (especially SHGC) very close to double pane (or better) for a fraction of the cost. -"Regularly refurbished"? In my experience, good putty on a painted wood single pane window will last ~50 years. When the time comes, a quality contractor can perform the service fairly quickly. Last I checked about $200 a window, maybe less. Track and lock maintenance apply to new and old windows. What do you charge to install a high quality name brand double hung double pane? -I've had no trouble with storm windows. They have all been easy to remove, install, and clean. Very durable. Never had an issue with condensation damage to the wood either. -Most of your "drawbacks" are non or very minor issues considering the typical cost savings of maintaining existing single panes. Film and/or storm windows can bring single pane energy efficiency very close to new double panes. Wood Single pane: $200 every 50 years for putty plus the cost to paint and maintain single pane locks and tracks (optional- plus perhaps $70 per window every 20 years for film). Double pane: perhaps $600-$800 every 30 years for new quality double panes installed. It's clear that it's usually cheaper to maintain existing quality single pane windows, even though energy performance may not be quite as good. Consider complete lifecycle cost. WoW, sure I'm happy to provide data. I'm waiting for yours. Respectfully your post sounds just like a double pane replacement marketing pitch. Lots of talk but little to nothing to support it. A recent study and some data on clear single pane, double pane, and film performance. https://cdn.llumar.com/drupal/na_arch_solar_specs_l2278.pdf https://www.mdpi.com/2071-1050/9/5/731/htm Not sure about the condition, size, access, or location of your friend's casement windows. Ex- If the casements open into a sunroom and still work well, why even consider replacing them (except for aesthetic reasons)?