Can the plate develop frost?
Yes, the PV could frost if the outdoor air is cold enough and there is enough moisture in the exhaust air from the building. Controls are offered that will mitigate the frosting of the plate unit. Timed exhaust is an economical way of dealing with frost. When the plate is frosting (determined by plate exhaust air temperature), the supply blower will turn off while the exhaust blower continues to blow warm air through the plate which melts any frost. Face and bypass is another option for applications where there must be a constant supply of outdoor air. If the plate begins frosting, the face damper closes (while the bypass damper opens) and diverts the outside air around the plate. Once the plate has defrosted, the dampers switch and the outside air is brought through the plate.
