Upon its launch in August 2016, the SANCO₂ Heat Pump Water Heater (HPWH) will become the first residential heat pump on the US and Canadian markets.
In developing the new product, Sanden is drawing from long experience in the Japanese market. In Japan heat pump water heaters have become a primary source of hot water provision in the residential sector. Many of these HPWHs are natural refrigerant-based – with CO2 models now comprising 98% of all new residential heat pump water heaters in Japan.
The SANCO₂ is a flexible two-piece system featuring an inverter-type compressor, DC fan motor and pump. The tank is installed indoors and the heat pump is kept outdoors (up to 25 feet away), with only water piping connections required between the two.
The outdoor heat pump has a 4.5 kW capacity inverter drive compressor. The indoor storage tank is available in two sizes, a 43-gallon [163 litre] version for families of up to four people and a larger 83-gallon [314 litre] model.
The heat pump uses the refrigerant CO2 to carry heat and cold through the heat pump system, which Sanden says helps “to improve performance, efficiency and recovery rates”.
The refrigerant is circulated in the system while it is still warm from the outside air. It then passes through the compressor. As its pressure rises, so does its temperature. The refrigerant subsequently passes through a heat exchanger to heat the water, which is then pumped to the storage tank.
The SANCO₂ delivers hot water back to the tank at 65ºC (149°F). Such a hot temperature allows it to be mixed down to the temperature required.
Its COP (coefficient of performance) – as measured by researchers at Washington State University – is 4.5, making it very efficient. Testing also revealed that it uses 70% less electricity in a northern climate.