Heat Pump Water Heaters


Why Heat Pump Water Heating?

It is generally accepted that the primary technology for water heating should be from renewable energy sources such as solar. However there are a number of situations where solar heating is not appropriate and heat pump water heating (HPWH) technology is the next best option and should be installed. Clearly renewable energy must be promoted over greater use of electricity.

Situations where HPWH is more appropriate than SWH would be in areas where the location has a high degree of shading, there is no appropriate north facing roof area, or the quantities of hot water used are small.

Supplier of HPWH

Solar Works is focused on meeting the customers needs Ė hot water, and supply both SWH and HPWH systems. We can offer SWH and HPWH systems as they are seen as being complementary and the potential customer can be offered the best hot water supply solution appropriate to their situation. Customers generally donít want to buy a particular technology, eg SWH or HPWH per se, they want the best hot water solution for their needs.


click image for an enlarged diagram
How a "SOLAR"
heat pump works:


Even on the coldest days, the ambient air holds solar energy provided by the sun - it contains "heat" which we can use. A heat pump captures this energy by taking the air around us into the unit (1), and uses the energy in the air to evaporate an environmentally friendly refrigerant inside the unit. The vapourised refrigerant is then compressed, which raises its temperature. The hot vapour is now sent round the tubes wrapped around the cylinder where water is stored (2). It gives up its heat to the water inside (3). Note that the vapour never touches the water in the cylinder - it transfers it's heat through a heat exchanger. The vapour now becomes liquid again. The ambient air that gave up its warmth is expelled (4), and new ambient air is drawn into the evaporator (1).

This evaporation/compression/condensation cycle is repeated over and over again until all the water in your cylinder is heated - it uses much less electricity because the heating is done by the air - the only electricity used is that driving pumps and fans!

HPWH Standards

Internationally technical standards for SWH and HPWH are often combined as many aspects of each technology are common. This also occurs in New Zealand where the standards AS/NZS 2712 and AS/NZS 4234 both cover SWH and HPWH.


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