Question for a window expert

[Sundancefisher]

Is putting tinfoil on the inside of a west facing window going to hurt a window?

Assuming using either cardboard to wrap tinfoil around or use painters tape to stick it to a window jam.

[EZM]

Originally Posted by Sundancefisher

Is putting tinfoil on the inside of a west facing window going to hurt a window?

Assuming using either cardboard to wrap tinfoil around or use painters tape to stick it to a window jam.

What you doing? Growing pot?

[Osky]

Don't most people use the tinfoil to make hats? Asking for a friend.

Seriously tho unless the foil could cause a trapped moisture issue I can't imagine what harm it would do.

Osky

[Sundancefisher]

Originally Posted by EZM

What you doing? Growing pot?

Room darkening for sleep.

[Sundancefisher]

Originally Posted by Osky

Don't most people use the tinfoil to make hats? Asking for a friend.

Seriously tho unless the foil could cause a trapped moisture issue I can't imagine what harm it would do.

Osky

Some older windows have a silicone like seal between the double low e panes. This window is newer...so the silver metal seal.

Only thing I could see being a potential concern.

Can’t find anything online.

Heating window may impact outside caulking maybe?

[fed]

Put the cover on the outside of the window if worried. Or buy some tinting and cover it

[MountainTi]

Originally Posted by Sundancefisher

Is putting tinfoil on the inside of a west facing window going to hurt a window?

Assuming using either cardboard to wrap tinfoil around or use painters tape to stick it to a window jam.

Just use the cardboard. No need for the tinfoil. All I do if I'm working nights.
Not going to get any darker by adding tinfoil is it?

[EZM]

Originally Posted by Sundancefisher

Room darkening for sleep.

OK - skip that idea.

Grow some pot, roll a bat every night and sleep like a baby.

Just teasing ....

[Jeron Kahyar]

If your glass unit has no coatings on the glass you will likely be fine.

If there is coatings on surface 2 (inside the unit on the outside pane of glass) I would recommend against the tinfoil. Best case on reflective coating is they cause additional pressure buildup (expanding gasses in the sealed unit) and the seal fales prematurely. Unlikely but worst case it can cause the glass to break.

The silver spacer you see in your window is siliconed in place. It is just there to space the two pieces of glass apart and the silicone creates the air tire seal between the two panes of glass.

Best thing I have found is just a good set of blackout blinds. I personally use blackout curtains with a wrap around curtain rod (allows you to get the curtain right up against the wall).

[Sundancefisher]

Originally Posted by Jeron Kahyar

If your glass unit has no coatings on the glass you will likely be fine.

If there is coatings on surface 2 (inside the unit on the outside pane of glass) I would recommend against the tinfoil. Best case on reflective coating is they cause additional pressure buildup (expanding gasses in the sealed unit) and the seal fales prematurely. Unlikely but worst case it can cause the glass to break.

The silver spacer you see in your window is siliconed in place. It is just there to space the two pieces of glass apart and the silicone creates the air tire seal between the two panes of glass.

Best thing I have found is just a good set of blackout blinds. I personally use blackout curtains with a wrap around curtain rod (allows you to get the curtain right up against the wall).

No coatings.

My thinking is the space between the window and blind is already getting really hot...so a covering shouldn’t be worse. Repainted the windows inside as they had started to peel. Outside is aluminum clad.

Have some rabbitgoo window covering as an option.

[Savage Bacon]

We have curtains with a white backing that doesn't let any light through. They work a lot better than blinds.

[MyAlberta]

Blackout draperies, there’s one product that always put fear into me. The darker the room gets, the more amplified light leakage is. Wall to wall, ceiling to floor, gets expensive. 10k worth of drapery to cover a 30k window set.

A cheap room darkening roller blind, sized to cover casings, mounted to lay against casings.

[Jeron Kahyar]

Originally Posted by Sundancefisher

No coatings.



My thinking is the space between the window and blind is already getting really hot...so a covering shouldn’t be worse. Repainted the windows inside as they had started to peel. Outside is aluminum clad.



Have some rabbitgoo window covering as an option.

The space between the drape (or blind) and the glass unit getting hot is not an issue. The issue comes when the air between the to panes of glass gets hot. The air (or argon in gas filled units) is hermetically sealed between the two panes of glass. As the gas heats up between the panes it pressurizes the inside of the unit. The resulting pressure can cause damage to the seals if it gets to high. With low emissivity coatings (Low E coating) on the glass it both absorbs and reflects some infaread radiation. When you reflect light back through the unit from the inside it causes a higher than normal solar loading. This is what causes the inside of the sealed unit to over heat and in turn over pressurise.

[Fwee6]

Had an uncle years ago that worked night shift.
He put tin foil on a south facing bedroom window, and was awoken around noon one day to a giant crack sound.

Long and short of it -- the glass got so hot as a result of the tinfoil it cracked top to bottom on a 3 foot high window. Costly fix.

I'd be treading with caution on the tin foil idea myself, or any other option that completely seals the glass from the inside of the house.

[brslk]

Cut a piece of foam insulation that fits snugly inside the window frame. That's what I did years ago when I worked nights and slept during the day.