Doors and Windows - Air leakage

We had some Simonton 5500 windows installed Nov. 2006. Some double hungs, a few sliders and a picture window.
The double hungs have alot of air leakage. We called the installer and he brought the Simonton disctrict sales manager over to inspect the windows and provide a remedy.
He brought some small foam inserts that are made to fit in the frame where the sash slides in the track. The installer said Simonton must have had this problem before since they have had to make these inserts. There is still air coming through between the sash and the track that it slides in.
Am I to expect air to leak around the sash or are these supposed to be almost air tight?
If this could be a manufacturers defect, I can have them replace the double hungs with sliders. My sliders don't leak at all.

They should be air tight.

No window is absolutely "air tight".

Many of the major brands of double hung have tested air infiltration rates of .10 - .25 cubic feet per minute of air leakage. Basically, what that means is, these windows will leak "some air" but that amount should not exceed those specifications, when the wind is X mph (whatever wind speed they were independently tested at).

If the windows were installed a little out of square, it could aggravate the problem. You can check this by opening the window just a crack, then raise it up high enough to observe whether there is an EVEN gap of light across the bottom. If there is a 1/4" gap on one side, and a 1/8" gap on the other, then the window is a bit out of square and it's then likely that when the window is shut and locked, the sash is not contacting the frame tightly.

It could also be possible that the windows are spread slightly in the middle. this can be checked by tipping both sashes in, then compare the measurements across the top, middle and bottom of the window (on the inside AND outside of the masterframe). They should all be equal. The problem with vinyl tilt windows is that the only thing keeping air out is the fuzzy weatherstrip, and it's not 100% air tight. But the foam blocks help slow the air that channels up the sides of the frame. They won't stop the air, but they will slow it.

You also did not say what the wind speed was- if is was super windy like it has been here a few times, then you will obviously notice some air channeling up the sides of those double hungs. Nothing is going to stop the wind completely when it's 30 or 40 mph. That's negative air pressure at work. Air comes in one side of the house and exits out the other side.

Maybe I shouldn't have said "air tight". I know there will be the possibility of a very slight air flow when high winds occur but not so much that it feels that the window is cracked open 1/16 inch. I used an incense stick to test the leak and the smoke was swirling around and blowing horizontal. The winds were only blowing 15-20 mph and these windows are tested in 70 mph wind tunnels.
I measured the windows and they are not out of square but when I measured the spread, the middle measurement was 1/16" closer in the middle than the top and bottom.
I called the district sales manager and told him I was sent some white foam inserts and he said they are the wrong ones and I should wait until I receive the gray ones to test for leaks. This foam is not a heavy duty material that will last for the life of the window. I feel, now, that I have been ripped off, this is a cheap fix for an expensive home improvement.
I read this forum and others about these windows and thought they were worth the money that they cost from what I read but this makes them look as bad as the cheapest windows I could have found because I am going to have to build frames and apply the heat shrink window film to make storm windows to keep on the interior to block the air flow coming around these NEW windows.
I plan to work on these guys until I'm satisfied with my windows and will update when it's all settled.

I thought Simonton was a fairly good window, you have corrected my thought. They should not leak to the point of being as noticeable as you describe. It is either the window or the installation or possibly both, your description of the service you have received makes me think it is the window.
A Certainteed installer.

I received the correct inserts for my windows and they do no better then the others. Now a "service tech" is coming to examine the windows Monday . I can hear the wind whistling through one of the windows.
Last week a woman from Simonton called to say the service tech was on a two to four week back log and he would call as soon as he could so I told my installer and he found the guy and it took him one day to call me. Thats SERVICE. He's also eager to learn how Simonton is going to handle this. He does a lot of business with Simonton and he doesn't want to be linked to a company that rips people off.
I can't wait for Monday. I will let you know what happens.

Some vinyl windows have a weak spot owhere the sash meets the masterframe on the bottom. Basically, it's the area where the side channels meet the bottom left and right sides of the sill. Sometimes you'll see companies glue a thin 1/16- 1/8" thick foam pad onto the sill in this area so that when the sash comes closed, it keeps air from blowing under the window and channelling up the sides.

Some windows just have bad designs that allow air leakage at corners where one type of weatherstrip ends (like a bulb weatherstrip on the bottom of the front sash) and another type of weatherstrip begins (like the fuzzy fin weatherstrips on the sides of the front sash.)

Keep us posted, we'll be interested to hear if and how they fix your problem.

A service tech came to look at the windows and he changed the fin seal to a heavier type, 180 to 250. He said Simonton changed it from the heavier to the lighter because customers didn't like the way it stuck out from the window. He also filled the jamb adjuster holes and some other holes in the frame that are there for installation but provide a channel for air to leak in. I had him wait while I checked the windows with an insence stick and the smoke was vertical instead of horizontal. The wind was blowing at 30 mph so that helped with the test.