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Heat pumps

How does a heat pump work?

A heat pump works on the same principle as an air-conditioner but in reverse. Heat from the air sucked in from outside is absorbed by an eco-friendly refrigerant gas in an evaporator - the gas is compressed (put under increased pressure) which causes its temperature to rise

Do heat pumps use electricity?

It does, but it is a highly energy efficient alternative to an electrical element geyser

Can heat pumps produce hot water at any time?

Yes, regardless of the weather, it will provide 100% of your hot water requirements

What are heat pumps’ tank capacities?

Tank capacities range from 100 to 500 litres; the size of tank you require depends on your daily hot water requirements

How energy efficient is a heat pump?

Heat pumps can be up to three times more energy efficient than electrical element geysers; electricity is used to only drive the compressor and fans and not for generating heat

Given heat pumps’ ability to dramatically lower your monthly electricity bill, what would the payback period be?

Depending on the unit installed, how it is used, and the ease or difficulty of the installation, recouping your investment in a heat pump will vary between 2 and 4 years

Are heat pumps sensitive to the climate?

Solar Heat pumps are designed to work outside at night and in temperatures as low as -10°C. It cannot freeze or overheat - modern heat pumps offer system protection against frost conditions

Do ambient temperature conditions have an impact on heat pumps?

Yes. Heat pump performance is influenced by ambient temperature conditions – i.e. low ambient temperatures = low efficiency; high ambient temperatures = high efficiency. However, seasonal variations ensure good average efficiency

Are heat pumps good for the environment?

Yes. Heat pumps derive energy from the air, which is unlimited and maintained in its ambient temperature range by the sun

How does a heat pump look?

A heat pump looks like an air-conditioner, a compact rectangular shaped metal unit

Are heat pumps installed inside or outside homes?

Units are positioned on the outside of homes in areas with a minimum of 120 cubic metres of free space around it (about the size of a double garage). There is no need to position the unit in a sunny spot

Are heat pumps dependent on the electricity supply?

Yes, heat pumps are dependent on electricity and operate on a cycle of 6 hours per day - if the heat pump has a back-up electrical element, the control must be configured to automatically trigger the element in case of unit failure. The size of the element should not exceed two thirds the size of your ‘old’ geyser’s electrical element - if it does, it is compulsory to install a timer to ensure the element remains switched off during 5pm to 9pm, the period of peak demand for electricity in South Africa

Are heat pumps noisy?

Heat pumps make a low-level humming sound like an air-conditioner - the point of installation should, therefore, be carefully considered

Are there specific maintenance requirements for heat pumps?

Yes, it is important to keep the coil-surface area clean of debris, leaves and dust to ensure maximum performance. The in-line strainer must also be cleaned regularly. Regular servicing is required, which would typically include inspecting the unit for any water or gas leaks

Are there specific installation requirements for heat pumps?

Yes, heat pumps must be fitted by qualified and licensed plumbers and installed as close as possible to where the heated water will be used

Is there a variety of systems?

  • In the case of a ‘split’ heat pump, the heat exchange device is on the inside. Cold water from a separate water storage tank (e.g. geyser) is heated in the heat exchanger and transported to the tank; the water does not mix with the refrigerant as they are in two separate loops
  • In the case of an ‘integrated’ heat pump the heat exchanger is in the form of tubes wrapped around the outside of the water storage tank; unlike the ‘split’ heat pump’, this system is equipped with a water storage tank

    Is there a variety of installations?

  • Yes, in the case of the ‘split’ system a heat pump is installed on an existing hot water installation - typically, the unit is installed against an outside wall and connected to your existing hot water tank
  • In the case of an ‘integrated’ system, the heat pump is installed with its own hot water tank - your existing hot water tank is disconnected
  • In the case of a ‘standard’ system a heat pump is installed with its own tank or connected to your existing electrical element geyser

    How much do heat pumps typically cost?

    Costs vary from manufacturer to manufacturer and according to customers’ specific needs. On a typical domestic unit of approximately 250 litres water capacity, the cost of the unit itself would be between 3 and 7 times the cost of an equivalent domestic resistant element geyser - the installation cost should be about the same or, in some cases marginally higher