Leaky Windows - Heat Losses

http://www.doubleglazingrepairs.com/ might be interesting reading? They are a long way away though the website may give an insight as to what can be done by an organisation more local.

Replacement, though undoubtedly a satisfactory solution as far as the seller is concerned, is likely to be unattractive as far as the prospective purchaser is concerned...

I'm near you in climate. The leakage is probably normal for old windows; newer ones should not leak air (although they might leak liquid depending on the type of seal). The leak will cost you a bundle and will create discomfort near the window. If all else fails, you can use a "rope" putty (I think the name is something like Mortite) that you get in the hardware store to seal up that area. It never hardens, so you take it off in the spring. I used that until I put in new windows (double pane, low E).

You didn't say what the windows are made of. As maintenance manager for a vinyl window manufacture here what i know.

All windows leak air. Even new ones. In testing them the amount of leakage allowed is dependent on the size of the window. All do not test their windows. When purchasing new windows look for a tag for inspection. Will list a number they where rated at. All the windows are not tested just a sample. The company that does the inspection then randomly test by coming in and pulling one from the line. Testing is done for air infiltration, rain leakage and structural.

One of the biggest leaks comes from the weep holes that drain rain water. Most the glass in the sashes are sealed to the out side. To compensate for any leakage through the seal drain holes are place in sashes. Which runs down into frame and out the front of the window. If water can get out air can get in. All the drains put there for water drawn through the wool pile seals. During storms with high winds there will be pressure changes that will suck water through.

The water is being drained out if by chance this water froze and he insulated glass unit was setting in it. The expanding water would force the panes of glass apart. This may damage the seal between them or possibly crack them.

If you can find them there are adhesive back pads of wool pile that can be placed to stop leakage.

In addition to the window types described by OzzieB, the most energy efficient windows have two or more panes with a vacuum or moisture free gas between the two or more panes. When they leak, visible condensation between the panes will indicate the 30 year warranty should be exercised to replace them.

To reduce your energy use well below budget please visit the following websites for holding heating bills between $100-$500/yr, depending location and the size of the house. www.cornstoves.info, www.groups.yahoo.com/group/cornstoves, www.msnusers.com/cornstoves, www.groups.yahoo.com/group/cornplace

As someone else mentioned, it's possible that while stopping air flow, some seal arrangements won't stop liquid.

The one thing liquid has over air in this situation, is capillary behavior. The liquid may in fact suck itself through the seal. Especially in this case where the liquid would have been sitting right above the seal on a double hung as you have described.

The only way to truly test whether your windows are leaking air, is to have a home efficiency test done (I've seen this on 'ask this old house') where you place a blower in one of the entrances to your home, and create negative pressure inside. Then you can check for drafts. Typically more air leaks between the window frame and the house then through the window itself.

You should be able to find someone who can do this through a local hardware store.

Windows alway allow for some air in enter the house. This is a requirement because the windows and doors and ridge vent(on the roof) is the only way to recirculate fresh air into the house. If there is a huge gap inbetween the windows I would be more worrier about someone being able to push the lock open and enter your home. No window you purchase will form an air tight seal in the locations you are talking about

aqua-doc,

The window repair people probably had more information available to them than we have from your post, such as age, material of construction, answers to questions they asked when you called them, etc. Although many have responded regarding the seals between the layers of glass in double-pane windows, I believe you were talking about water running out through the "meeting rail" crack between the upper sash and the lower sash of the double-hung window. This is a very difficult place to seal effectively because the full length of the rail (width of the sash) closes simultaneously.

In traditional wood windows, this rail has about a 5-7º bevel, so it should be pinched tight when the windows are closed and the latch turned. High quality ones even had interlocking metal weatherstripping on this rail. However, as windows and houses age, the window frames can settle, or deterioration on the wood can occur, or the sash latches become loose, so the windows do not seal well.

Within the family of vinyl windows, the double-hung type is the one with the highest amounts of air infiltration. Typically seals in these are a synthetic felt pile on a narrow plastic strip which is slid into a slot in the sash extrusion. Over time, this felt pile can wear or have portions of the felt damaged, or can break and separate, or can shrink. Likewise, UV light slowly degrades the vinyl itself so it becomes stiffer and less compliant to make a good seal when closed. Many brands have semi-interlocking ridges (which can be deformed or damaged) on the two meeting rails, to enhance their seal. Water leaking past this seal is a normal process, enhanced by capillary action as mentioned by others.

Metal (aluminum) windows are very similar to vinyl ones in their construction, but they are usually less prone to damage or deterioration. However, if they have thermal breaks between the inner and outer extrusions, then there can be some problems, here. Your post does not mention excessively cold windows or frosting on the frames during winter, so I don't think you have problems relating to metal windows.

Bottom line? Probably the window repair people were giving accurate information. To maintain indoor air quality, you must have a certain amount of air exchange between the house and the outdoors to eliminate indoor contaminants and supply oxygen, etc. This problem gets worse when we consider the wide variety of synthetic materials available for use in homes, with the outgassing of various plasticizers, glues, and chemicals, as well as byproducts of biological processes such as mold or mildew growth. A home energy audit would be good. It can cost $500, but is very helpful in identifying where problems exist as well as priorities for work; but get references and check them to see what former customers think of the auditor and the report. What you do will depend on the level of discomfort from the windows or other conditions in the home, the cost versus the probable payback for each option, how long you intend to remain in the house, if the work will result in a sufficient return in future market value, and the availability and cost of the fuel for future heating or cooling.

About all I believe we can do here is jiggle your thought processes and give you various factors to consider as you search for your answers. I hope we have helped.

--JMM

I have replaced my house old windows myself, installed double pane as they are more energy efficient, once installed, I sealed the outer edge with caulking material, soft type in So. Cal. but if you live in cold weather, go to the hardware store and buy a can of the foam type. It will give you better insulation and cost a few dollars. test application on a wood or metal board to observe expansion. If you know of a automotive paint store, they have automotive sealants from 3M, duramix and fusor among others. tools you may need are a caulking gun and a knife or razor to cut any excess.

Just a short story to relate my dilemma and my solution. - I too had leaky windows. In the wintertime, it was too uncomfortable to be near any one of my double hung, wood frame windows. Not having much $$$ to spend to replace all of the windows, I opted to replace a few at a time. I started by ordering new vinyl frame, double pane, double hung windows to replace the ones that were located at the kitchen sink area. The following winter, I was surprised to find that on extremely cold and windy days, you could still feel some cold air coming through the seal where the top and bottom overlap in the center. I called the manufacturer and to make a long story short, was told this condition was normal. Even though the new windows were an improvement over the old ones, I thought that there must be a better way to stop the cold air from coming in. I didn't replace any more windows for two years. Meanwhile, I noticed that I had no air infiltration or uncomfortable feeling when I was near my two large picture windows located in the living room. Then it struck me! I was putting windows that opened in areas where I never opened the windows and therefore didn't need windows that opened. My solution was to replace all of my windows with double pane, vinyl framed one piece, windows. They have plastic dividers that snap in on the inside to give the effect of 9 lights. No more air comes through, no seals to maintain, and the best part is that last winter my heating oil usage was down by 53%. That's right, I used a little less than half the fuel that I used the year before. BTW, I have 3,800 sq. ft. of heated living space which I keep at 72 deg. F. On another topic, this year I'm blending 35% waste vegetable oil with the #2 heating oil to reduce heating cost even more.

Good point about putting fixed window glazing where you only need the light. However, where you have sleeping rooms, the codes require two means of exit, one of which has to be either outside or to a sprinklered and fire resistant exit path. Usually this means operable windows with the specified size of clear opening.

--JMM

I have one double hung in each of the 3 bedrooms to provide exits. I have also mounted roll-up ladders in faux window boxes located on the inside. Just open the window, throw the ladder out and away you go. Actually caught the kids sneaking out one night when they thought the misses and I were asleep. Oh well, I taught them how to use the ladders and we practice using them on an irregular basis.

Be careful with foam. Darn stuff expands and jams the window jam from moving. Might even crack something. Don't use too much (If any). After succeeding in making the first window so tight it wouldn't move, I now stick to fiberglass insulation that you stuff (not too tightly) into the spaces around the windows. Carefully remove the trim around the window (always pull nails through the trim (not back out or it'll splinter the wood), then add insulation around the window. This January we finally got replacement windows. They didn't use foam either. Double hung vinyl - made a big difference in our 50 year old house... Have two latches that attempt to seal the gap, seem to work pretty based on infiltration test results.