Heat Pumps for Household Hot Water

These are, as the name suggests, pumps that are used to move heat from one source to another and in the case of residential use are best utilised to provide hot water for home heating although they can help ‘top up’ your hot water supply and would be best suited to HVAC use (Heating, Ventilation & Air Conditioning).

Heat Pumps generally deliver hot water at a lower temperature than typical household systems such as Gas or Electricity which is why they are better used to provide home heating, than direct hot water.

Whilst there will be an element of “free energy” the pumps themselves use electricity to operate, but if you run them from solar panels then this will reduce the amount of power they consume from your mains supply.

The main types of design available are Air Source Heat Pumps (ASHP) & Ground Source Heat Pumps (GSHP) and can qualify for payments from the Renewable Heat Incentive (RHI).

Air Source Heat Pumps.

heat pump ashp

Typical Air Source Heat Pump

ASHP’s are fitted outside the house and are about the size of a standard external air conditioning unit, working by absorbing heat into a refrigerant fluid from the surrounding atmosphere.

The fluid (volatile & compressible) is then compressed which makes it hotter and run through a heat exchanger where it de-compresses, releases its heat and is subsequently recirculated to collect more heat in a continuous cycle.

  • Amazingly, ASHP’s can collect heat from the atmosphere even at temperatures as low as -15 degrees Celsius.

There are 2 further distinctions in this category and that is in the way the ASHP function, one type is known as Air-to-Air and is best suited to household heating systems that circulate hot air into the home by use of vents. This method does not produce hot water for use in the home.

The other is known as Air-to-Water and can provide hot water but is best used for home heating that uses circulating water, such as underfloor heating or wall mounted radiators.

Ground Source Heat Pumps

ground source gshp 2

Typical Ground Source Heat Pump

The temperature below ground is surprisingly constant and GSHP’s take advantage of this much in the same way as an ASHP takes heat from the atmosphere by compressing, circulating & expanding a volatile refrigerant fluid within the system.

This is a much larger installation than ASHP’s as fitting them entails laying a series of pipes approximately 2 metres underground (ground loop) on your property and therefore you should have enough room to suit the size of the loop needed, in simple terms the bigger the loop, the more heat can be absorbed (100 metre deep vertical bore holes can be used as an alternative where space is at a premium). This method can produce hot water for use in the home.

Energy Efficiency Benefits

Whilst it is possible to get payments from the Renewable Heat Incentive for using Heat Pumps as they are Micro Combined Heat & Power (Micro-CHP) improvements, to get the most out of them your house should also be as energy efficient as possible, simple steps such as double glazing, water tank insulation, cavity wall insulation & loft insulation can help a lot.

You should also get a full appraisal of your existing heating installation to ensure it is operating properly and that it is compatible with working alongside a heat pump.

This type of home improvement should be installed by a qualified professional and in order to receive the RHI it must also be installed by an MCS (Microgeneration Certification Scheme) certified contractor or company. - see more about contractor certification at our FAQ's

Fully Installed Heat Pumps.

Air & Ground Source Heat Pump Prices from MCS Contractors.