# Managing Air Leak in Double Pane Vinyl Windows



## XSleeper (Sep 23, 2007)

Double hungs often require chimney blocks, which is basically just a piece of foam that gets wedged down the side channels. 

Every window has a certain amount of air leakage that is considered "normal". That's why they have air leakage test ratings on the labels. 









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## UltraRed (Jan 20, 2018)

XSleeper said:


> Double hungs often require chimney blocks, which is basically just a piece of foam that gets wedged down the side channels.
> 
> Every window has a certain amount of air leakage that is considered "normal". That's why they have air leakage test ratings on the labels.
> 
> ...


thanks XSleeper.
my mistake. i have single hung windows, not double hung...does this make a difference re the chimney blocks?


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## Randy Bush (Dec 9, 2020)

You also might want to check the condition of your weather strip on these. Anderson uses a bubble type that wears out and flattens with age. This is replaceable. Also under that bottom piece there is normally a piece of filtering material. I find on a window that is correctly sealed does not need additional foam on those sides. 

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## UltraRed (Jan 20, 2018)

Randy Bush said:


> You also might want to check the condition of your weather strip on these. Anderson uses a bubble type that wears out and flattens with age. This is replaceable. Also under that bottom piece there is normally a piece of filtering material. I find on a window that is correctly sealed does not need additional foam on those sides.
> 
> Sent from my SM-A115A using Tapatalk


thanks randy; is the weather strip in the vertical channel or along the horizontal edge? i do see some type of fuzzy strip that seems in pretty good shape along the inside of the horizontal edge. i don't see anything in the vertical slot.


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## dd57chevy (Jun 21, 2015)

I'd have to agree with XS .It is somewhat common to get air penetration coming up the jamb slot .

Take one of those small 39 cent kitchen sponges & cut a piece to fit .


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## Randy Bush (Dec 9, 2020)

UltraRed said:


> thanks randy; is the weather strip in the vertical channel or along the horizontal edge? i do see some type of fuzzy strip that seems in pretty good shape along the inside of the horizontal edge. i don't see anything in the vertical slot.


Well those have the better seals then , the fuzzy ones are the seals . Like the other have said really would not hurt to put the foam on the ends . That fuzzy seal should be on all 4 sides of the window. 

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## XSleeper (Sep 23, 2007)

No it does not matter that they are single hungs. But you likely have a channel balance that will knock out a chimney block as soon as you open the window.


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## Bud9051 (Nov 11, 2015)

Does the air leakage cause a comfort issue when someone is standing or sitting near those windows or is it just an energy concern?

Bud


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## Randy Bush (Dec 9, 2020)

Bud9051 said:


> Does the air leakage cause a comfort issue when someone is standing or sitting near those windows or is it just an energy concern?
> 
> Bud


There should not be that kind of air leakage. Unless some seals are shot or missing. 

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## Bud9051 (Nov 11, 2015)

Agreed but we don't really know how much air he is getting. My point is to not be overly concerned as that leakage is a small part of what our homes need and it isn't coming through the framework like much of the air is.

Bud


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## ChuckTin (Nov 17, 2014)

Usually there's a latch mechanism to allow the movable pane to be completely removed for cleaning. I do not see that in the OO's pictures. But I'd look to see if it can come out and then examine the seals to see if they're a type that can still be replaced.

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## Windows on Wash (Aug 30, 2011)

Good double hungs do NOT require blockers, but the percentage of double hungs that are good is about 3% on average.


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## UltraRed (Jan 20, 2018)

Bud9051 said:


> Does the air leakage cause a comfort issue when someone is standing or sitting near those windows or is it just an energy concern?
> 
> Bud


the issue is the smell of smoke coming in when the window is closed.


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## UltraRed (Jan 20, 2018)

ChuckTin said:


> Usually there's a latch mechanism to allow the movable pane to be completely removed for cleaning. I do not see that in the OO's pictures. But I'd look to see if it can come out and then examine the seals to see if they're a type that can still be replaced.
> 
> Sent from my Pixel 4a using Tapatalk


i looked and there is no obvious way to remove the window that slides.


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## XSleeper (Sep 23, 2007)

They are side loads. They have channel balances, as I mentioned in post #8. You have a plastic clip in the center of the track on each side (left of your red arrow). You pull that out on bottom with your fingernail, and it hinges on top. The bottom pulls out about 3/8". Once you pull out the bottom of both clips, you raise the window up about halfway, grasp the top of the sash with your left hand, the bottom of the sash with your right hand, and you force the sash as far to the left as you can. At that point, the right side of the sash can be swung into the room as if the left side was a hinge. Once the right side of the sash clears the frame, you pull the sash out of the left side to remove the sash.

You need to be very sure that you raise the window up high enough when you do this. As you raise it up, you will feel something catch on the clips. That is your channel balance. You need to continue lifting the sash up about 4 more inches, at which point, you should be able to see the bottom end of the channel balances one each side under the sash. If you don't see both channel balances in the side tracks, STOP. Close the window and start over, checking to see if the clips are pulled out correctly. Only when you are sure you have hooked both balances on the clips should you attempt to remove the sash. Those channel balances are like little rocket slingshots if you don't know what you're doing.

Assembly is the reverse of disassembly. And I'm sure if you look on YouTube and search for "how to remove a sideload window sash" you can see it done. All sideloads are pretty similar.


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