Insulation -
Insulation is not as important as a good seal. For
example, the best insulating windows available aren't much help if
you leave them open 1/2"!
After achieving a good seal, however, insulation is
important. A single-walled flap is not
satisfactory for the same reason that single-pane glass is not: It
just doesn't insulate very well. While single-pane glass is
completely replaced these days by dual-pane glass, most pet doors
sold on the market today provide no more than a
1/8"
thickness of vinyl between the living area of the home and the
outside weather.
The Endura Flap consists of a sealed unit that is
slightly thicker than a dual-pane glass unit and provides comparable
insulation qualities. |
Heat Transfer Barriers -
Heat transfer across an air space in a sealed unit is caused by air
currents moving within the space. These currents are caused by the
continuous heating and cooling of the air inside the unit.
The Endura Flap is divided by horizontal barriers
which serve to reduce the effect of these air currents.
A trade Off - We could have filled the flap
interior with insulation for better insulation performance. We
didn't for the same reason that dual pane windows aren't filled with
insulation: It's better if you can see through. |