Window U-value

[55stone]

Hey guys quick question here I have a small garage I'm going to insulate and heat in northern Indiana. I'm adding 2 roughly 24"x36" windows and am wondering how big of a difference a .3 to .5 U value is. The same window is like half the price for a .5 U value over the .3. Any input on this would be awesome!! Thanks

 

[walta]

The U value is the reciprocal of the R value so
1/U=R
1/.5 =R 2
1/.3 = R 3.33

The windows will make little deferens if you only heat the garage a few hours a year. But will make a big difference if you heat it 24/7.

Also you will be able to feel the difference if it is 20° and spend time near the window.

Your heat source and fuel cost also is important factors.

Walta

 

[The Cobbler]

pay for insulation once, pay for heat everytime the furnace comes on
but, I don't see high savings of heat on 12 sqft @ r-1.3 additional rvalue

 

[Richard Cranium]

agreed, if this was a shop you were going to be working out of full time, I would say to get the better one, But a weekend use area, Save the money.

 

[55stone]

thank you for the input guys!! i appreciate it

 

[James-W]

So what is the verdict? Are you heating the garage all the time, or just occasionally when working out there?

 

[Lelandwelds]

If you are wrong and get cold, buy some Polygal from Interstate Plastics and mount it outside each window. It will keep stray baseball's from ruining your day too.

 

[theoldwizard1]

pay for insulation once, pay for heat everytime the furnace comes on

Hmm ... Maybe I should have Trademark that saying when I started using it years ago ! Just kidding !! I am glad to see someone else agrees.

For your location, good quality double pane glass is fine. If you have one side of the building with a lot of glass, your could consider and interior removable tint film. Put your dollars into more attic insulation and making sure you have no air leaks around the windows and doors.

My sister bought a new house less than 10 years ago. I was surprised when she told me that several of the thermal pane seals had failed ! I have premium thermal pane replacement windows that are over 25 years old and they are all still sealed.

 

[Falcon67]

Having put 5 24x36 windows in my shop, I would worry more about the quality of the window components than the U value. Nothing more PITA than having to cut 1/2" aluminum sticks to hold open your nice double pane LowE insulated glass windows.