ceiling insulation

Al Letellier

We just did a Wirsbo system and the specs said use unfaced fiberglass with no air gap.....it works fine. I'm assuming you're talking about extruded plates and not the thin aluminum plates.

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bovide_3

ceiling insulation

Doing a staple up radiant floor with transfer plates, 8" o.c.. Wood floor above. What kind of insulation should I use in the ceiling? I just saw a foil-type reflective insulation-no fiberglass. Does it work? If fiberglass, use faced or unfaced?

bovide_3

the plates are wirsbo heat emission plates, #A5075002.
Watts radiant specs call for foil faced insulation, w/2" air gap. Guess that's a grey area.

Mark Eatherton1

Reflective surfaces and radiant energy...

If you're going for conduction, skip the foil and push the insulation up against the plates.

The Watts method assumes suspended tube install and they're going for radiant, conductive and convective transfer.

Studies have shown that unless the aluminum is 99.9% pure virgin aluminum, AND the surface is completely smooth, AND there is no dust to mess up the spectral reflectivity, reflective surfaces render themselves null in the heat transfer/reflection equation.

I've seen suspended tube jobs before where the insulation was pushed up tight against the tubes and the floor just wouldn't carry the load. I had a crew go thru and pull the insulation down to establish a 2" gap of air below the tube, and the floor came up to temp immediately. The backing on the insulation was the standard paper, not the reflective stuff.

If I were you, I'd go with unfaced fiberglass insulation and push it up against the plates.

ME

bovide

excellent

thanks much. that is exactly what I'll do. I read all of your articles in contractor mag.