Heat Pumps

 

Heat pumps are in common usage today, most often in refrigerators and air-conditioners. However they can be also be used very effectively to produce hot water, just as a reverse-cycle air conditioner can produce warm air.

Heat pump hot water systems draw their heat from the surrounding atmosphere and while they perform better as ambient temperatures increase they are not limited to sunny days. The main advantage with heat pumps is that they can heat water in situations where solar isn't viable, such as in homes with poor solar access.

Heat pumps operate with a co-efficient of performance (COP) of around three, which means they make three units of energy available for every unit they consume, but this varies with the outside ambient temperature.

Since they can heat in almost any weather, but at very cold ambient temperatures they become less efficient. Heat pump water heaters are designed to be switched on at all times like a refrigerator, so selection of an appropriate electricity tariff is important. However they do not have a large power consumption. It is possible to put a heat pump on a timer to run it at times of low electricity tariffs and to reduce noise at night.

A rebate of $600 is available from the Federal Government to people whose homes were destroyed in the 2009 Victorian bushfires who install heat pump hot water. The same conditions apply as for the solar hot water grant above.