Heat pump installation: one request, one installer in Malta

Ground source heat pumps take heat from pipework buried in trenches or boreholes. They run more steadily through a cold spell, but the groundworks make them far more expensive, and they only make sense where there is land to dig or a budget for drilling.

Air-to-air heat pumps blow warm air into rooms, much like air conditioning, and do not heat your hot water.

The size of the heat pump should come from a room-by-room heat loss calculation: wall and floor construction, glazing, insulation, ventilation and the indoor temperature you want to hold on a cold day. It should not come from the output of the boiler you are replacing, which was often oversized in the first place.

The same calculation tells the installer which radiators can stay and which need to be larger. A heat pump is most efficient at low flow temperatures, so an undersized radiator in a north-facing bedroom is the difference between a warm room and a system that has to run hot all winter. Ask to see the room-by-room figures, not just the headline kW.

Hot water is a separate question. A combi boiler heats water on demand; a heat pump heats a stored cylinder. The installer needs to know how many people live in the house and how you use hot water to size the cylinder and find a place for it.

• a room-by-room heat loss calculation and the design flow temperature
• which radiators are replaced or upsized, and whether pipework changes
• cylinder size and position, and what happens to the old boiler and tanks
• where the outdoor unit goes, and the noise assessment for that position
• whether the electricity supply or fuse needs upgrading

For a heat pump or heat pump water heater, check the current schemes of the Regulator for Energy and Water Services (REWS). REWS runs incentive schemes for residential users, such as the Renewable Energy Sources Scheme and the Water Heater Scheme, and publishes the conditions for each year's scheme. Conditions and deadlines change from year to year, so check them before you sign.

Ask the installer whether the equipment and the installation meet the scheme's conditions and who submits the application.

Source: rews.org.mt

You confirm your mobile number with a text code and your email address with a link. We then show the request to businesses in your area, without your name or contact details. Only one business can take it on; it pays Offrano for the request, and it costs you nothing.

Before that business sees your details, we email you its name, address and phone number. We check only that it is a registered business, for example through its Malta Business Registry entry or VAT number, not the quality of its work. We cannot promise that a business will respond; if nobody takes the request within 21 days, we withdraw it. Offrano is not a party to any contract for the work.