Radiant Barrier - Worth it? (Austin, Wichita Falls: apartment, appliances, credit)

[Synopsis]

I had ridge vents installed on our home a couple of years ago after hail damage, and I can DEFINITELY say that they are worth it. Our electric bill went down almost 20 percent during the summer.

As for radiant barrier, I do believe that it is worth it as well. It purportedly deflects up to 80 percent of the heat away from your attic, resulting in up to 40 percent savings on your electric bill.

Another thing that might save you money in the long run is to install on of those flash hot water heaters that only heat the water when you are using it. They also have the added advantage of providing hot water almost immediately instead of having to let the water run for two or three minutes, resulting in water savings.

[Synopsis]

Originally Posted by scuba steve

Spray-on is quicker for whoever is putting it up, but has proven to be less effective through experiments conducted. Sheets of the stuff, stapled to the inside of the rafters (3 1/2 inches below the decking) has proven to be most effective. It's sold by the roll - that's the price I mentioned above.

Age of the house doesn't matter. What experiments have proven to be most effective is the combination of soffit venting, radiant barrier stapled to the rafters a few inches below the decking, and ridge venting. The superheated air between the decking and radiant barrier will escape through the ridge vent and is replaced with cooler air from outside the attic space through the soffit vents.

I agree, the reflective material that is installed is much better than the spray painted stuff (IMO). It's a lot like aluminum foil from what I understand. And I forgot about the soffit vents. The more of those you have the better.

[SAnativegirl]

Scuba Steve, Do you have any recs for someone putting in radiant barrier at that price?

[banker]

Originally Posted by Synopsis

I had ridge vents installed on our home a couple of years ago after hail damage, and I can DEFINITELY say that they are worth it. Our electric bill went down almost 20 percent during the summer.

As for radiant barrier, I do believe that it is worth it as well. It purportedly deflects up to 80 percent of the heat away from your attic, resulting in up to 40 percent savings on your electric bill.

Another thing that might save you money in the long run is to install on of those flash hot water heaters that only heat the water when you are using it. They also have the added advantage of providing hot water almost immediately instead of having to let the water run for two or three minutes, resulting in water savings.

Radiant barrier DOES NOT deflect up to 80% of the heat away from your attic. I have heard that it drops your attic temp from 15-30 degrees depending on ventilation and type of radiant barrier used.

My parents had the spray on radiant barrier installed and I wasn't impressed. They have had a drop in electric bills, but they had ridge vents, 12" of new insulation, and new high efficiency windows done the same month the radiant barrier was sprayed in...so it is hard to say what had the biggest impact. The job that was done just doesn't look thick enough to cover and reflect out enough heat to do the job.

I have the radiant barrier decking - which costs me less than $500 when I built my house a year ago. I have no comparison of a house without the radiant barrier decking - but I know my current 3,214 square foot home costs less to keep at 78 than my last home which was 25 years old and only 1,732 square feet. Again - it is the combination of things, proper ventilation, insulation, radiant barrier and roof color that all adds up to energy efficiency.

[scuba steve]

Originally Posted by SAnativegirl

Scuba Steve, Do you have any recs for someone putting in radiant barrier at that price?

I quoted the material only, which from the place I bought from was $135 per 1,000sqft (13.5 cents per square foot). That means you get to put it in for that price .

However, I do know the owner of a reputable company that can do the work - I can provide the info if you'd like. I did it myself because I do pretty much everything around the house.

Originally Posted by banker

Radiant barrier DOES NOT deflect up to 80% of the heat away from your attic. I have heard that it drops your attic temp from 15-30 degrees depending on ventilation and type of radiant barrier used.

My parents had the spray on radiant barrier installed and I wasn't impressed. They have had a drop in electric bills, but they had ridge vents, 12" of new insulation, and new high efficiency windows done the same month the radiant barrier was sprayed in...so it is hard to say what had the biggest impact. The job that was done just doesn't look thick enough to cover and reflect out enough heat to do the job.

The spray kind doesn't typically even meet the Department of Energy's definition for a radiant barrier. Another reason why I'm a huge fan of the regular kind...

Department of Energy Website:
http://www.energysavers.gov/your_hom.../mytopic=11680

[Steel Man]

Originally Posted by scuba steve

Spray-on is quicker for whoever is putting it up, but has proven to be less effective through experiments conducted. Sheets of the stuff, stapled to the inside of the rafters (3 1/2 inches below the decking) has proven to be most effective. It's sold by the roll - that's the price I mentioned above.

Age of the house doesn't matter. What experiments have proven to be most effective is the combination of soffit venting, radiant barrier stapled to the rafters a few inches below the decking, and ridge venting. The superheated air between the decking and radiant barrier will escape through the ridge vent and is replaced with cooler air from outside the attic space through the soffit vents.

Home Depot carries it:

[banker]

Originally Posted by scuba steve

I quoted the material only, which from the place I bought from was $135 per 1,000sqft (13.5 cents per square foot). That means you get to put it in for that price .

However, I do know the owner of a reputable company that can do the work - I can provide the info if you'd like. I did it myself because I do pretty much everything around the house.


The spray kind doesn't typically even meet the Department of Energy's definition for a radiant barrier. Another reason why I'm a huge fan of the regular kind...

Department of Energy Website:
Energy Savers: Radiant Barriers

Great link. Interesting about the spray on type not typically meeting the DOE's definition of a radiant barrier. It does seem that the foil you apply after market and the deck sheething with it preapplied seems to be the best method.

[cwh]

Originally Posted by Steel Man

Home Depot carries it:

Yes, but mail order is much cheaper Need order another roll and finish my attic. The first roll covered about 80% and dropped the attic temps significantly.

[scuba steve]

Originally Posted by Steel Man

Home Depot carries it:

Home Depot does carry it, but I remember it costing about $.5 / square foot. That's about 3X the cost from Radiant Guard, where I ordered it online. I have measured no performance difference between the kind from Home Depot and what you can buy from Radiant Guard. The Home Depot variety is more effective when used to wrap a hot water heater as the bubble wrap will improve heat retention in that situation. May also work as a pipe wrap but I haven't done a study yet.

Ain't engineering fun!

[TexHwyMan]

Originally Posted by kevcrawford

radiant barriers are the new hot thing.