Reflectix Insulation

J Sullivan

I am quoting a staple up job in a new log home. We will be using the plates with the tubing. The contractor that is building the house want me to use the reflectix insulation. I have never used it before and I would like to get some suggestion about it, and also how well it works.

J Sullivan

Reflectix Insulation

I am quoting a staple up job in a new log home. We will be using the plates with the tubing. The contractor that is building the house want me to use the reflectix insulation. I have never used it before and I would like to get some suggestion about it, and also how well it works.

jim lockard

Try this

WWW.Reflectixinc.com

kevin coppinger_4

JUNK...

if you want to use it under the staple up fine... just use it in conjuction with fiberglass batts. A lot of the claims it makes or assumed are overblown...kpc

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Kal Row

i just noticed the reflectix adds on the right...

never realized they were automatically generated by google from the thread's context - aint capitalism great

Joe Bologna

Good advertising, though

From the Reflective Technology section of their website, it says: "Would you rather drink coffee from a Thermos jug or a foam cup hours later?"

Pretty realistic comparison, huh?

Personally, I think the guy who wrote that should only drink convenience store coffee from a wooden mug wrapped with Reflectix, hours later, while the guys doing real insulation jobs drink Starbucks from a thermos.

From the R-values part of the website, there's an R-value of "respectable". I tried looking that one up in the ASHRAE Fundamentals.

Think I see the "seven layer" part though. Would that be: air film, poly, aluminum, air space, aluminum, poly, air film?

Doesn't it kinda raise a red flag when you see misleading advertising like this? It does for me.

It's true, r-values mainly address conductive heat loss. But that's a very big part of the picture. And that little air gap in bubble foil isn't much conductive heat loss insulation.

Maybe you can get away with it with staple up between two heated areas, where you're not insulating from outdoor temperatures.

But just maybe, the installation and material cost isn't all that different between foil-faced fiberglass batts vs. Reflectix.

Never checked, never used Reflectix, when radiant and conductive insulation is available in one package. But I have heard foil faced fiberglass is hard to scare down in some areas.

Then there's the issue of settling dust compromising the radiant insulating properties. I didn't read about fire issues, but if the general has done it before, I guess it'll pass code in that area.

Hell... why not let him design the rest of the heating system?

My guess is he figures he can save time or money (and therefore make tikme or money) by using Reflectix. Can't blame him for that... IF the performance is there.

Someone came up with a Canadian study that had some data on bubble foil performance. I'd try digging that up, along with a cost comparison between batts and Reflectix.

Dave Bush

They're claiming R16.8 on their under-floor product.

http://www.reflectixinc.com/script/products/product.asp?ID=54


Actually looks like good stuff, really....

Unknown

In the installation you are talking about, it works great. At first. You have the airspace, you have the reflection, that's great; it doesn't have the same problem as the canadian studies were finding for this stuff under SLABS, which have little radiant component to their heat transfer downward. Unfortunately, ORNL did research showing that you can lose up to 50% performance in as little as 1-5 years from dust accumulation in upward-facing underfloor applications, so while it's great at first, in the long run it's not worth the cost.

Also, if you're over unheated space or under heavy R floor coverings, you want R value as well. And always insist that the rim joists get packed and sealed well!

The GC isn't going to get the callback if the system won't keep up. Log home, underfloor.. time to be conservative.

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Joe Bologna

That's quite a claim.

But then again, advertising is supposed to make product look like really good stuff. I also see R = 1.1 under concrete slabs, and R = 4.0 for a water heater wrap.

That R = 16.8 indicates the equivalent of 5-1/4 inches of fiberglass batt. I think not.

Don't get me wrong, there are applications besides outer space where radiant barrier is ideal. If I were building in Florida, had a roof with soffit and ridge vent, I'd install it across the roof rafters. Heat absorbed by the roof radiating towards the inside of the building would be reflected back. Lots of convective heat would vent out the ridge through the channel formed by the space the foil barrier makes between the rafters' face and the roof decking. The fiberglass or cellulose above the ceiling would handle the conduction.

When I take a raft trip down the San Juan, my ice is gonna be in a foam-lined cooler, not a cloth and bubblefoil picnic basket. But it's gonna have some bubble foil lain across the top of the cooler to protect it from the sun's radiation heat gain.

Radiation is a part of it, but it's not everything.

My gut feeling is that it might not be the worst application for Jason, between radiant floor tubing above, and living space below. Convective heat transfer downward is low, and the low delta T works in its favor.

But I'm also thinkin' there's better options whose installation costs aren't that different. That extra insulation might pay off in a zoned system when the downstairs doesn't need heat. I suspect the downward loss of heat could be more than insignificant, compared to batts.

What's your experience with performance of this application Dave? Do you like it because of their advertising claims, or because it installs fast and easy? Or for some other reasons?

Constantin

No way...

When I see claims for R16.8 for a product that's 5/16th of an inch thick and it's not a vacuum-panel, I call BS. In my mind, claims like this bend the truth at best by exploiting limitations in the R-test rather than measuring actual heat loss in an under-slab situation. The real-life tests coming out of Canada and elsewhere confirm my suspicions.