Heat Pumps compared to Solar Water Heaters

An Air to Water Heat Pump provides an ideal energy efficient hot water system alternative for both domestic household use, or for larger Commercial applications.  In reality a Heat Pump provides slightly less energy savings when compared to a domestic solar water heater, but there are a number of other significant advantages associated with the use of an Air to Water Heat Pumps.

One major advantage of the Heat Pump is the aesthetic appearance that is gained by not needing any thermal solar panels and in some cases a storage tank on the roof of the building to ensure efficient operation.  In some cases roof structures may have to be reinforced when they are required to support the weight of a domestic sized solar storage tank that can weigh in excess of 400 kg.  In addition, the installation cost of an Air to Water Heat Pump is very simple compared to the installation cost of a solar water heater, and this significantly lower installation cost for the Heat Pumps should also be taken into consideration when assessing the overall installed cost of either product alternative.

Another advantage of the Air to Water Heat Pump is the low energy input from the electricity supply that is required to operate the system, while at the same time producing an output of around 3 times more than the actual electrical input, when operated in average ambient temperatures of 20 degrees Celsius.  This results in an energy saving (reduction) of approximately 75% when compared to traditional electric water heaters.  In Regions where the average ambient temperature is higher than 20 degrees Celsius the actual energy savings can be higher due to the extra heat energy that is available from the ambient air in these locations.  Air to Water Heat Pumps do not require direct sunlight to operate efficiently because they collect free energy from the ambient air.    Contrary to popular belief, a solar water heater does requires back-up electrical energy to operate the booster element during periods of inclement weather, low radiation periods, and at night time when there is a need to supply hot water during those times.  When comparing similar volumes of hot water delivery the annual booster or back-up energy needed to ensure solar thermal water heaters provide a continuous supply of hot water during all weather conditions, or if hot water is needed during the evening period, is similar to what is expended annually for a Heat Pump to drive the evaporator fan and compressor.   A domestic sized Heat Pump could, in some cases, operate from Photovoltaic (PV) solar cell system due to the low energy input needed when compared to the actual output that is delivered in the form of hot water.  This makes the Heat Pump products ideal for isolated and heavily forested locations such as remote Eco Resorts.

By Mel Peatey.