exposed paper backing on the insulation

[Charlie R]

Look at using a foil covering product such as "Tempshield BB-STD107 Double Bubble Foil Reflective Insulation" over the unfaced insulation.

[Marc]

That's right. There's air wash and convection loss which would be huge, and there's also thermal barrier issues. Insulation, lacking substantial thermal mass isolated inside of it, is pretty much worthless. There's nothing to hold the heat.

A layer of drywall inside a layer of (fiberglass) insulation makes for a pretty good air seal and thermal mass barrier.

There's no need to hold the heat. That's for the mass wall concept.

Marc

edit: corrected the bold font.

[kurt]

No need to hold the heat.... What are you talking about? You clearly live someplace where heat isn't something folks think about much.

Maybe go R60+ ceiling and R40 walls and make it airtight with paneling (or drywall), and you got something, but I'm suspecting the gentleman is talking about a "normal" wood frame assembly, not a super insulated airtight box or mass wall.

[Jerman]

Thanks for the info everyone, helps my decision.

[SNations]

That's right. There's air wash and convection loss which would be huge, and there's also thermal barrier issues. Insulation, lacking substantial thermal mass isolated inside of it, is pretty much worthless. There's nothing to hold the heat.

A layer of drywall inside a layer of (fiberglass) insulation makes for a pretty good air seal and thermal mass barrier.

Kurt, I'm with Marc here in not understanding what you mean by needing thermal mass. The concept of mass wall doesn't have much use in Chicago, where winter temperatures get low and stay low. So thermal energy is always going in only one direction -- out.

A good and proper amount of insulation isn't going to perform any differently with 3/4 inch drywall or 1/2 inch drywall or even 1/64 inch drywall (assuming such a thing existed), as long as the drywall is airtight.