Questions tagged [r-value]

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Can R values be averaged?

Suppose there is a wall and half of its area has R-value 10, and the other half has R-value 20. Is the total R-value of the wall 15? In other words, can R-values be averaged weighted by area? Please justify your answer with math. R-value is defined…
David Levner
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Should electrical box face plates be caulked?

I am in a dilemma whether to caulk electrical box face plates or not. The reason to do it is to improve the R value of the house but a downside is that any removal will be slightly more messy and will likely tear the paint around the plate. Where I…
amphibient
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Garage insulation really need R-39?

I read it from here: https://www.homedepot.ca/en/home/ideas-how-to/home-repair-and-maintenance/how-to-choose-insulation.html It recommends my garage "Walls Above Grade" should have R-19/ R19+R7.5 / R24+15 at best. I am not sure how can I fit in 3.5"…
Yashiharu
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How are insulation R-values calculated for wall cavities of inconsistent thickness?

I'm designing a house which will have unconventional wall construction that varies in thickness. The wall cavities will be filled with dense-packed cellulose, rated at R-3.7 per inch. I want to understand how to be sure that I'll meet IECC/IRC code…
Bungle
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How to find a very low U-value replacement window for a bathroom?

I found 0.27 for a Pella 250 series at Lowe's. I would like to find a window with a lower U-value. How do I go about that?
aparente001
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Where can I find the U-factor (U-value) for a Pella window?

I am trying to compare the Pella windows sold by the Pella sales person with the Pella windows sold at the big box stores (Lowe's, Home Depot). I have found a spec sheet with this information for Lowe's. I found a spec sheet for Pella Pella but it…
aparente001
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