Rockwool Insulation compared to Prodex Total Insulation
Rockwool insulation does not prevent radiant heat transfer (The primary source of heat-flow in and out of your structure). Without a radiant barrier, when the roof gets very hot (as in summer), it radiates solar-generated heat down into the attic insulation. Rockwool insulation primarily reduces heat transfer by trapping warm air. It has a high radiant heat transfer rate and is a very good radiator of this absorbed and retained heat. As surfaces radiate infrared rays in all directions, the heat trapped in rockwool insulation during the day will radiate down through the ceiling into the air-conditioned living space at night even if the night cools down. This means you will have to run the air-conditioning system even at night wasting energy. Using radiant foil insulation will prevent this problem. An aluminum foil radiant barrier in the attic will block up to 97 percent of this heat from reaching the insulation and the air-conditioned living space below.
Rock and Sag wool insulation, sometimes called mineral wool, is spun from slag and other rock-like materials. If wet, rock and sag wool insulation can pose problems. Rockwool insulation retains a large amount of water. Wet insulation in your home can promote mold and mildew. Concerns regarding the health and safety effects of rock and sag wool are understandable.
Alternative to Rockwool Insulation: A better insulation product would provide a radiant barrier, vapor barrier and provide more R value. It would also provide some elasticity to make installation easier.
Prodex Total Insulation is a radiant heat barrier (Reflects 97% of radiant heat (the primary source of heat flow). It is a vapor barrier (0.033 gr/m2hkPa) and it is a reflective insulation R value 16. Prodex has a high yield point, which means its considered elastic -- It can be stretched during installation. That also adds the benefit of a clean look once installed. It is composed of 5mm (1/4 inch) closed cell polyethylene foam sandwiched between two 99% pure aluminum, low emissivity surfaces.
radiant barriers : reflective insulation : vapor barriers
July 17, 2013