Foil Insulation R Value

Worth mentioning to get the equivalent r value to what the manufactures claim on the packaging the installer has to use spacers under the insulation to keep the prescribed air gap between the ducts and the foil.

Foil insulation r value.

This testing to designate an r value only applies to conductive heat flow not radiant heat flow. Air inherently has an r per inch value of 5 6 and is an excellent insulator when radiation and convection are controlled. Most metallic bubble wraps are about an r 1. Products with foil facing help the panels resist moisture vapor.

Triple pane windows with low e surfaces perform better than a triple pane window without low e surfaces because of the reduction of radiation low emittance across the air spaces. It provides about r 5 per inch. The foil facing also makes it very easy to seal with good quality foil faced tapes. R value is a term to describe how quickly heat will pass through or be absorbed by a product.

Working with home insulation boards insulation panels typically come in 4x8 foot sheets. Smaller sizes are also available. Just as the absorbency of a raincoat is unrelated to its ability to repel water the r value of rfoil does not fully measure its ability to insulate and redirect heat energy. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.

As a foil faced polyisocyanurate foam insulation enerfoil tm s r value actually more than doubles when it is twice as thick as you can see from the chart above. This material offers the highest r values about r 6 to 6 5. Basically r values range from 1 5 to 7 and the higher the number is the more effective the insulation sheet is at increasing thermal efficiency and thereby insulating your home. What is the r value or r rating of radiant barrier foil insulation.

Polyiso is typically used with a foil facing and it has an r value of 7 0 to 8 0 per inch of thickness. The reflective foil facing makes it an excellent insulation board when radiant heat is involved. The astm c236 1224 tests that determine a products r value yield the following results for rfoil reflective insulation. Heat flow down r 10 6 heat flow horizontal r 6 8 heat flow up r 5 3.

The sheets themselves are not created equally. Other materials may only have a fifty percent increase in r value when their thickness is doubled. An r value is a measure of an insulation product s resistance to thermal heat transfer. The r value is in essence the measurement of an insulation sheet s ability to resist heat flow.