Fan Coils - The best way to cool your home with a heat pump
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Heat pumps are best known for providing efficient, low-carbon heating, but many systems can also help keep your home cool during warmer weather. When paired with fan coil units, a suitable air source or ground source heat pump can deliver both heating and cooling through the same system.
What is a fan coil unit?
A fan coil is a compact indoor unit connected to your heat pump’s water-based heating and cooling system. It contains a heat exchanger and a quiet fan that circulates room air across it.
During winter, warm water from the heat pump passes through the fan coil, heating the air before gently circulating it around the room. In summer, a cooling-enabled heat pump can reverse the process and supply chilled water, allowing the fan coil to absorb heat from the room and deliver cooler air.
Unlike traditional radiators, fan coils use their built-in fans to move air across the heat exchanger. This allows them to heat and cool a room much more quickly and effectively.
Cooling without a separate air-conditioning system
For properties that already have a compatible air source or ground source heat pump, fan coils can provide a cost-effective alternative to installing a completely separate air-conditioning system.
Because they use the home’s existing heat pump and water-based pipework, fan coils can cost a fraction of a new whole-home air-conditioning installation in suitable properties. There is no need to install a separate outdoor AC unit for every area, helping to reduce equipment, installation work and the visual impact on the building.
The exact saving will depend on the existing system, pipework and number of rooms being cooled, but fan coils can be an especially attractive option when cooling is considered during a heat pump installation or renovation.
How effective is the cooling?
Fan coils provide active cooling rather than simply circulating air like an ordinary electric fan. They remove heat from the room and transfer it back through the heat pump system.
Their effectiveness depends on several factors, including:
- The cooling capacity of the heat pump
- The size and number of fan coils
- Room sizes and levels of insulation
- Solar gain through windows
- Water flow temperatures
- The positioning of each unit
A correctly designed system can make a noticeable difference to comfort throughout the summer. However, cooling requirements should always be calculated separately from the property’s heating demand, as rooms with large windows or significant solar gain may require greater cooling capacity.
Fan coils also need suitable condensate drainage. When warm room air meets the cold heat exchanger, moisture can form inside the unit, just as it does within conventional air conditioning. Correct drainage, insulated pipework and appropriate controls are therefore essential.
Floor, wall or ceiling mounted
Fan coil units are available in several different styles, allowing them to work in both new-build and existing homes.
Floor-mounted fan coils can resemble modern radiators and are often a practical option when replacing existing emitters.
Wall-mounted fan coils are installed at high level and provide rapid air circulation, with a familiar appearance similar to an air-conditioning unit.
Ceiling-mounted or concealed fan coils can be installed within a ceiling void, leaving only discreet grilles visible. These are particularly well suited to new builds, extensions and major refurbishments where pipework and drainage can be incorporated into the design.
The right option will depend on the property, available space and the level of cooling required.
Can fan coils be retrofitted?
Yes. Fan coils can often be retrofitted to existing air source and ground source heat pump systems, provided the heat pump is capable of producing chilled water and the wider system is designed to operate safely in cooling mode.
The assessment should consider:
- Whether the heat pump supports active or passive cooling
- The existing pipe sizes and circulation capacity
- Controls and zoning
- Condensation protection
- Insulation around cooling pipework
- Condensate drainage from each fan coil
Not every heat pump is automatically cooling-ready, and simply replacing a radiator with a fan coil will not create effective cooling without the correct system design. Aura can assess the existing installation and identify what equipment or alterations may be required.
Heating and cooling from one integrated system
Fan coils make it possible to use one heat pump system for comfortable winter heating and valuable summer cooling. They respond quickly, work effectively at the low water temperatures produced by heat pumps and can be controlled independently in different rooms or zones.
For homeowners planning a heat pump installation—or those who already have an ASHP or GSHP—fan coils provide a flexible way to improve year-round comfort without necessarily installing a separate air-conditioning system.
Want to know whether fan coil cooling could work in your home? Contact Aura for an assessment of your property and existing heat pump system.
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