What is a good R-value for insulation?

What R-Value Insulation Do You Need? While the R value of 7 is more effective than the R value of 3, If you live in a home that is in a very hot climate, it would potentially be wasteful, unnecessarily expensive, and counterproductive to install insulation with an R value rating of 7.

What insulation has the highest R-value?

USA Premium Foam®
USA Premium Foam® has the highest R-Value in its class. Our proprietary USA Premium Foam Insulation has a superior R-Value of 5.1 per inch, which is 35% higher than any retrofit stud wall application. In fact, it’s the highest on the market.

Does aluminum foil have an R-value?

You would get an insulation value of R-9.60. According to ASHRAE, when just a little condensation is visible on aluminum foil, the emissivity can reach 0.2 to 0.3, which would decrease that R-value down to R-3.86.

What is R-value in thermal insulation?

The R-value is a measure of resistance to heat flow through a given thickness of material. So the higher the R-value, the more thermal resistance the material has and therefore the better its insulating properties. Therefore it would improve the thermal resistance by more than 21 times!

Where is most heat loss in a house?

Take a look at this thermogram of a house. The roof and windows are the hottest, showing that most heat is lost from the house through those parts. Heat energy is transferred from homes by conduction through the walls, floor, roof and windows. It is also transferred from homes by convection .

Does foil insulation really work?

Foil is used in space-faring craft because of these great properties preventing radiant heat loss. Because space is a vacuum, there is very little heat lost by conduction, so foil is absolutely perfect.

Does bubble wrap have an R value?

Most brands of foil-faced bubble wrap are only 3/8 inch thick or less, and have an R-value of only 1.0 or 1.1. (The bubble wrap layer is unnecessary, since it adds cost to the material without adding any useful thermal performance.)

What is the are value of reflective insulation?

Here are a couple of quotes from Reflectix literature: (1) “A reflective product installed in an open attic as a Radiant Barrier has no R-value. R-values for reflective products are obtained when the product faces an air space in a “enclosed cavity”.”

What do you need to know about reflectix insulation?

Reflectix® can provide verification for all R-values stated for all products and applications. What about R-values for a Reflective Insulation, and why do they vary with application?

How are radiant barriers and reflective insulation systems work?

Radiant barriers and reflective insulation systems work by reducing radiant heat gain. To be effective, the reflective surface must face an air space. Dust accumulation on the reflective surface will reduce its reflective capability.

How are R-values related to conductive heat transfer?

The higher the R-value, the more resistant a material (or building assemblage) is to conductive heat transfer. Reflectix® can provide verification for all R-values stated for all products and applications. What about R-values for a Reflective Insulation, and why do they vary with application?