Patent ID: 8214936
Filing Date: 2012-07-10
Classification: A61H,F28D

Abstract:
1. A spa system, comprising: a tub having an inner side wall defining an inner surface forming a tub cavity, wherein the tub is configured to hold sufficient fluid to immerse at least a substantial portion of a user seated in the tub, and wherein the tub defines an upper peripheral edge extending around the cavity, and wherein inner side wall has an upper portion adjacent the upper peripheral edge, the tub further including a generally upright side wall forming an outer skirt having an enlarged outer tub surface facing outwardly, the tub defining an interior space between portions of the inner side wall and the outer side wall; at least one fluid outlet for exit of fluid from the cavity; a heat pump system including a water side heat exchanger and an air side heat exchanger, a compressor, and refrigerant conduits fluidly interconnecting the water side heat exchanger and the air side heat exchanger to the compressor and providing for flow of refrigerant through the water side heat exchanger and through the air side heat exchanger when compressed by the compressor; and wherein: the water side heat exchanger, the air side heat exchanger, and the compressor are positioned within the interior space of the tub; a water pump and a plurality of fluid conduits fluidly interconnecting the pump to the water side heat exchanger and fluid inlets and the fluid outlet, such that the water pump circulates water from the tub cavity through the water side heat exchanger, whereby the water is heated prior to flowing into the tub cavity through the fluid inlets; a temperature sensor configured to sense a temperature of water in the tub; a controller operably connected to the temperature sensor and to the heat pump system, wherein the controller is configured to control the heat pump system based, at least in part, on the temperature of the water in the tub; and the water side heat exchanger comprises a multi-pass unit having a housing comprising a first and a second tubular portion each defining a side wall and having inlets and outlets connected to the fluid conduits to provide for flow of fluid from the first tubular portion to the second tubular portion through the housing; and including: a first coil connected to the refrigerant conduits, and wherein the first coil is made of a tubular metal material with inlet and outlet portions that extend through the side wall into the first tubular portion and wherein the inlet into a first tubular portion is located at a first end of the first tubular portion and the outlet is located adjacent a second end of the first tubular portion so that the fluid flows the length of the first coil; a second coil connected to the refrigerant conduits, and wherein the second coil is made of a tubular metal material with inlet and outlet portions that extend through the side wall into the second tubular portion and wherein the inlet into a second tubular portion is located at a second end of the second tubular portion adjacent the second end of the first tubular portion and the outlet is located adjacent a first end of the second tubular portion so that the fluid flows the length of the second coil.