what is the refractory brick?
I have one in my attic and it payed for itself in one AC season.I had temps in the 130 s and now it never gets above 105.
A fire brick, firebrick, or refractory brick is a block of refractory ceramic material used in lining furnaces and kilnsA refractory brick is built primarily to withstand temperature, but should also usually have a low thermal conductivity to save energyUsually dense firebricks are used in applications with extreme mechanical, chemical, or thermal stresses, such as the inside of a wood-fired kiln or a furnace, which is subject to abrasion from wood, fluxing from ash or slag, and high temperaturesIn other, less harsh situations, such as a natural gas fired kiln, more porous bricks are a better choiceThey are weaker, but they are much lighter, easier to form, and insulate far better than dense bricksIn any case, firebricks should not spall under rapid temperature change, and their strength should hold up well during rapid temperature changes.