Patent ID: 8584733

Claim:
An automatic operable, dynamic purge system for a heat recovery wheel comprising: a heat recovery wheel assembly having one or two fixed radial seals and a dynamically movable radial seal, said one or two fixed radial seals and said dynamically movable radial seal being configured for directing a controlled supply of air into an exhaust air stream passing through a heat recovery wheel of said assembly, wherein said one or two radial fixed seals are on one face of said heat recovery wheel and said dynamically movable radial seal and is located on an opposite face of said heat wheel recovery; wherein when said heat recovery wheel includes said one fixed radial seal and said dynamically movable radial seal, said fixed and dynamic seals are located to create a single purge so that purged air travels through said wheel once, and wherein when said heat recovery wheel includes said two fixed radial seals and said dynamically movable radial seal, said fixed and dynamic radial seals are located to create a double purge so that purged air travels through said wheel twice, said dynamically movable radial seal being secured by an automatically operable rotatable wiper blade, wherein as said wiper blade rotates, said dynamically movable radial seal rotates while remaining approximately radial to said heat recovery wheel.