[OT] Radiant Barriers?

Rob,

We did it a couple of years ago and noticed an immediate difference in comfort and electricity savings.

We had all three things done at once: venting, radiant barrier (spray on) and insulation blown in. Our upstairs unit was struggling to maintain 78 in the afternoon. After the improvements, it not only maintained the 78 temp, it cycled on and off frequently.

Our summer electric bill dropped about 20%. Our example may be extreme as it wasn't well insulated and did not have proper venting.

Good luck. Oh, and negotiate as the price seems to be flexible.

 

We have it in the house in Plano. Seems to have been effective but lots of other variables have into play so its hard to say how much. I'm thinking of having it done at the Villa also, so I guess I would recommend it.

 

Is your roof transparent?

 

Rob,

We had the radiant barrier done as well. There are many different concoctions of the stuff they spray and there are a select few that actually work and work well.

It is very important to get the correct one.

At the time we did it, I remember reading an independent scientific study that rated a number of the formulas against what they are supposed to do. Some actually do almost nothing.

I'd have to dig around a bit to see if I can find that information. Feel free to give me a call.

Having said all that, we've never gone back to figure out the cost savings. We've got 2-3 years worth of post barrier data and 6-7 years worth of pre barrier data.

 

Home Depot isn't really the best place to go.

Attic vents are crucial to get airflow moving through the attic space. The radiant barrier can then do it's job, but without lots of airflow, the radiant barrier alone won't drop your bills the way most people want to think it will.

 

I wish I had an attic to spray the stuff into. My electricity bills are enormous.

 

My folks had EAS (HD's contractor) do the same stuff Rob was quoted. The vents are a big part of it. Making a huge difference over last year according to them.

 

I just put a new roof on my house due to hail damage and was asking my roofer about radiant barrier. He said that first you want to make sure that your attic ventilation (turbines and soffit vents) are working correctly. I had all my vents redone, and the roofer then recommended EAS for the radiant barrier. I have not done it yet, so I will be interested to see how it works out for Rob.

 

When we built our house 3 years ago I did a lot of research on energy saving products.

Among other things, we installed radiant barrier, ridge vents and perforated soffits. It is important to not only have enough ventilation at the roof level but to also have an air flow starting at the soffits / eaves. If you dont already have perforated soffits you can cut and install vents all around the house.

The ridge vent is a constant release of hot air at the higher and hottest point of the roof. They are more expensive than air hocks but in my opinion it is worth it for a Texas house.

The foil radiant barrier works well but I dont know the effectiveness of the spray on.

I am not sure what the net effect was because we dont have a before and after comparison but I do know that our electric bills are surprisingly low considering the square footage.



You could wait for a hail storm and have the insurance company pay for it all.

 

If you have old single paned windows, having them professionally re-sealed/caulked will also make a noticeable improvement.

 

We've been thinking about doing the same thing, but I don't know whether it would be worth the expense. Already have "decent" ventilation and deep insulation, so no issues there. Our house is 4,400+ with electric bills of $300 in summer (so far) and winter less than $200. I just wonder if you can get the same/near result by adding insulation and ventilation, skipping the RB treatment. ??

BTW Rob, if you need help perforating your soffits, I have an idea that would be a lot of fun for several of us that live nearby...

 

You guys are making me nauseous with your low electricity bills!!

My next house is going to be 'normal'!!!!

 

We just had a new roof put on, and had ridge vents installed. It's helped the temp significantly. They're not as effective as they could be due to the type of roofline I have, but every little bit helps.

I also agree on the windows. We just replaced the living room windows (also due to hail damage), and the difference in heat transmittal from the old-style to these new triple-pane metal-impregnated things is pretty amazing. We'll probably replace all the windows in the house over the next few years.

 

My parents just replaced all their old single pane windows with vinyl 2 pane. The savings is coming in at about 20% off the electric bill.

 

I looked at radiant barrier as a side business and researched it quite extensively.
IMO The "best" way is with new radiant barrier roofing deck.
Second best stapled foil on the undersides of the joists.
Third would be spray.
Spray is the cheapest.
Figures.
Difficult to compare efficiency vs costs = payoff.

The end all is to have a foamed enclosed attic with radiant barrier roof deck.
This keeps the attic within a few degrees of the home year round.

 

I'll trade 'em....

 

I was under the impression that the radiant barrier does not work as well if there is already a lot of shade on the roof. Once the roof is in the shade, it should cool down close to the ambient air temperature.

For example, we have mature trees along the west side of my house and the majority of the roof is shaded from about 3:00 on. My house is probably not a good candidate for a radiant barrier. However I could benefit from more insulation and better windows.

Jeff