Radiant Barriers: Hype or Hope?

I’ve been researching “Radiant Barriers” for the last few days; wondering if they can contribute to our home energy saving efforts. We called Home Depot to schedule a consultation. I hoped to eliminate the constant barrage of questions I would normally have; especially since prior to the call, I knew absolutely nothing about radiant barriers. I only knew it sounded good in theory.

Most do-it-yourself radiant barriers are of the rolled foil type, either applied to the rafters or the attic floor. EAS (Efficient Attic Systems), a partner to Home Depot, list how they create a radiant barrier in your attic. I did not see foil in any of the pictures, and I wonder if this sprayed on gunk will reflect well and have low emissivity.

Here are some links I found helpful.

http://www.radiantbarrier.com/
http://en.wikipedia.org/wiki/Radiant_barrier
http://www.freepatentsonline.com/4776142.html

For in-depth Department of Energy information on Radiant Barriers click here . Although this is dated June 1991, there is still plenty to learn and digest.

Before doing my research, my first 2 questions would have been:
how much?
and how much will it save me?

After doing some research and gaining some rudimentary knowledge of the subject; my first two questions remain:
How much?
and how much will it save me?

They may have to be my last 2 questions answered. Whoever they send out must see the space and find out what & how much before they can give me an estimate.
I’m eagerly awaiting the consultation. I have questions and I’m confident they will have the answers. I’ll post my findings here after the appointment.