Abstract
Specimens of extruded and expanded polystyrene, polyurethane, polyisocyanurate, sprayed polyurethane, phenolic, fibrous glass, cellular glass, lightweight concrete, fiberborad, perlite, andcork insulatin were frozen in air and thawed in water up to 948 times. Their moisture contents were determined periodically, and relationships developed previously at the US Army Cold Regions Research & Engineering Lab (CRREL) were used to determine the effect of that moisture on their insulating ability. Most insulations became quite wet, which caused them to loos much of their insulating ability. After 400 freeze thaw cycles, phenolic, cellular glass, fibrous glass, and fiberboard lostmore than 3/4 of their insulating ability. Lightweight concrete and perlite about 2/3, cork and gypsum lost about 1/2 and expanded bead polystyrend lost about 1/3. Sprayed polyurethane, polyurethane, polyisocyanurate, and extruded polystyrene foam lost only 6 to 16 percent oftheir insulating ability after 400 cycles. Cellular glass is quite resistant to moisture, but when water in cut cells as its edges froze and expanded, it was progressively broken down into a black powder. After 25 freeze-thaw cycles, it had less than 20 percent of its original insulating abilty.
Specimens of extruded and expanded polystyrene, polyurethane, polyisocyanurate, sprayed polyurethane, phenolic, fibrous glass, cellular glass, lightweight concrete, fiberborad, perlite, andcork insulatin were frozen in air and thawed in water up to 948 times. Their moisture contents were determined periodically, and relationships developed previously at the US Army Cold Regions Research & Engineering Lab (CRREL) were used to determine the effect of that moisture on their insulating ability. Most insulations became quite wet, which caused them to loos much of their insulating ability. After 400 freeze thaw cycles, phenolic, cellular glass, fibrous glass, and fiberboard lostmore than 3/4 of their insulating ability. Lightweight concrete and perlite about 2/3, cork and gypsum lost about 1/2 and expanded bead polystyrend lost about 1/3. Sprayed polyurethane, polyurethane, polyisocyanurate, and extruded polystyrene foam lost only 6 to 16 percent oftheir insulating ability after 400 cycles. Cellular glass is quite resistant to moisture, but when water in cut cells as its edges froze and expanded, it was progressively broken down into a black powder. After 25 freeze-thaw cycles, it had less than 20 percent of its original insulating abilty.
Date
9/1997
9/1997
Author(s)
Wayne Tobiasson; Bryon Young; Alan Greatorex
Wayne Tobiasson; Bryon Young; Alan Greatorex
Page(s)
352-359
352-359
Keyword(s)
degradation; freeze thaw; insulation; moisture; protected membrane; thermal resistance
degradation; freeze thaw; insulation; moisture; protected membrane; thermal resistance