Energy savings in a piece of foam
A simple molded block of foam illustrates the extent of available technologies ready and waiting to reduce energy consumption and associated greenhouse gases.
Common in many US homes (and perhaps homes in other countries) is the folding attic stair. More akin to a step ladder than a stair, the device, which folds into the ceiling below an attic, is used to gain occasional access to the space to expand storage options or for maintenance of equipment that might be residing there. The opening for the stair is fairly standard at about 2 feet by 5 and is covered when closed by a sheet of thin plywood attached to the ladder and its spring-loaded closing/opening mechanism.
That thin sheet of plywood, which may have some thin foam insulation attached, is effectively all that separates the interior of the house from the temperatures of the outside world.
Attics are generally unheated/uncooled spaces, usually vented to the outside. In the dead of night - without the sun beating down on the roof above and trapping heat inside - an attic can be nearly as cold as the outside itself. The only heat that may be drifting into the space, warming it a bit, is radiant heat finding its way through inadequate insulation or, you guessed it, from that often poorly sealed, minimally insulated folding attic stair.
Like winter cold, summertime is a problem too. Attic temperatures can reach well over a hundred degrees on days that are, in fact, far cooler than that. That heat can be transferred to the cooler air inside the living space of house, adding to the struggle of air conditioning systems.
To energy conscious homeowners the loss of warm air into the attic by way of the closed folding attic stair is obvious. It’s in the ceiling. Warm air rises. The thin door of the stair and its poor sealing is obviously an escape route for heated air.
(Less obvious is the heat gain from a hot attic on the living space from the attic stair, but it’s still part of the problem.)
Handy homeowners often find ways to seal and insulate the stair. A box made of pieces of foam taped together with duct tape that sits over the stair opening in the attic - pushed aside when access is needed - is one more sophisticated method.
Fortunately, Atticap Corporation of Acton, Massachusetts and insulation maker Owens Corning recognize the dramatic energy loss possible by this hole-in-the ceiling-to-the-outside-world. Atticap calls it Draft Cap (tm) and the Owens Corning branded (and Pink Panther Pink) version is called a PINKcap (tm). (Atticap makes it for Owens Corning.)
In either white or pink foam it’s a thick molded polystyrene (EPS) foam box that resides above the folding stair opening. It’s light enough to be pushed aside when ascending the stair, pulled back into place when descending it. It’s designed so that the folded stair fits neatly inside it. With a proper flush fit it’s rated at R11 or 12.
The “caps” are Energy Star rated by the US Environmental Protection Agency.
Both companies do an adequate job of explaining the cap’s attributes and the problem of warm air heat gain/loss on their respective websites. Owens Corning includes dramatic infrared photos of heat loss. Owens Corning, as well, includes a state-by-state list of distributors - most prominently Home Depot stores in selected states. Atticap will sell you one directly via the Web.
The folding attic stair is the cause of significant energy loss whether the house is in Nebraska or North Carolina. Small energy saving efforts add up. A simple low tech block of foam can save a homeowner money. Nationwide, worldwide, the waste of energy and associated greenhouse emissions from folding attic stairs must be considerable. With a simple piece of foam properly installed, that waste can be eliminated.
Owens Corning PINKcap
Atticap Draft Cap