Air Source Heat Pumps & Underfloor Heating (Real Example)

Air source heat pumps are becoming a more popular way to heat a home but work in a different way to traditional heating systems and must be used with the right indoor heating apparatus to work effectively.

Underfloor heating can work with water-based central heating systems, which in turn can work with an air to water heat pump.

Underfloor heating can work well with air source heat pumps because of their large surface area and the typically lower temperature water flows from a heat pump. However, underfloor heating may only be suitable for lower, ground, floors and can be harder to retrofit into existing homes.

As air source heat pumps work at lower temperatures compared to other heating systems such as gas, more importance is placed on the indoor heating apparatus to release the heat as efficiently as possible.

Underfloor heating can therefore be a popular choice with air to water heat pumps. We have underfloor heating serving the lower floor of our home for use with our air source heat pump.

Our air source heat pump works alongside underfloor heating to heat our home

We discuss more about using underfloor heating and air source heat pumps in more detail below, explaining how underfloor heating is setup in our own home for use with our heat pump system.

Air Source Heat Pumps & Underfloor Heating: Example

We have an air source heat pump that was installed when our house was built over five years ago and provides us with heating. We also have a hot water tank that allows our heat pump to provide us with domestic hot water.

This is an air to water system, meaning that it works alongside a water-based central heating system.

Air Source Heat Pump Plate
Our air source heat pump system is the air to water type that works with water-based heating apparatus such as underfloor heating

The other type of air source heat pump is air to air but work with space heating systems such as air handlers rather than a central heating system (our guide on air to water vs air to air heat pumps covers all the differences).

As part of our central heating system we have underfloor heating on the lower floor of our home and radiators on the upper floor.

This compromises our entire house heating system and we have no other heating system installed, such as a gas boiler.

Each area on the lower floor of our home is served by an individual underfloor heating system, with accompanying thermostats so that temperatures can be controlled differently across our house.

Air Source Heat Pump Thermostat
Thermostats in each room/area of our home work with individual underfloor heating systems

These thermostats work alongside the main central heating system, which is located inside one of our downstairs cupboards.

Air Source Heat Pump Hot Water Tank
All our main internal heating apparatus

Inside here is where the control valves for each individual underfloor heating system can be found.

The control valves for our underfloor heating

The control panel for our overall heating and hot water system is located just outside this cupboard.

Air Source Heat Pump Water Heater Control Panel
Our overall air source heat pump heating system can be controlled from this panel

Our air source heat pump therefore works together with underfloor heating to provide heating for the lower floor of our home.

It’s an effective system and we’ve had no problems in the 5+ years we’ve been using it.

Air source heat pumps work differently to conventional heating systems and extract and deliver heat more slowly at lower temperatures. As a result, the system that releases the heat into a home needs to do so as efficiently as possible.

At lower heating temperatures, larger surface heating equipment is required to release heat effectively. Underfloor heating works over a large area and has a large surface area in which to work, making them ideal for use with air source heat pumps.

However, not all floor construction in a home can be suitable for underfloor heating installation.

Concrete floors in the lower floor of a home make them ideal for use with underfloor heating, but upper floors may typically not be made of suitable construction.

With an air source heat pump system it’s therefore typical to have underfloor heating on the lower floor but use radiators on any upper floors.

While we have underfloor heating serving the lower floor of our home, the upper floor is only served with radiators for heating.

Air Source Heat Pump Radiator
While underfloor heating only serves downstairs in our home, radiators only serve upstairs

To work effectively with an air source heat pump, radiators should also be modern and have large surface area.

When installing an air source heat pump system into an older home, underfloor heating can be more work compared to installing radiators but using radiators across a whole home can be just as effective when set up correctly.

For new build homes or homes that are undergoing extensive renovations, underfloor heating can be an effective system when used alongside an air to water heat pump.

Other Air Source Heat Pump Underfloor Heating Requirements

Well Insulated Indoor Space

As air source heat pump systems work at lower output water temperatures, it can be important to keep the heat in for long enough for indoor temperatures to sufficiently rise.

Insulation is therefore another important requirement for air source heat pumps to be used alongside underfloor heating.

This may not be such as issue with new build homes but can be with older houses. If a home has a poor level of insulation, heat can escape as quickly as it’s released.

Consult an air source heat pump installer about the best ways to insulate your home and the level of insulation required.

Suitably Sized Air Source Heat Pump

An air source heat pump will need to be suitably sized to provide the required heating, cooling or hot water for a home.

The square footage of your home and the heating apparatus used, such as underfloor heating, can determine the size of the heat pump. In general, the bigger your home, the larger and more powerful your heat pump will need to be.

Our heat pump is adequately sized for our 5-bedroom house that uses underflooring heating on the lower floor, radiators on the upper floor and a hot water tank to provide hot water.

Our heat pump isn’t used for cooling and we have separate air conditioning units for that.

Our 11.2kW air source heat pump is suitable sized to provide heating and hot water for our home

See our article on what size air source heat pump you need for more information.

An installer will able to calculate the right size and power output heat pump required using information such as whether underfloor heating and/or radiators will be used indoors.

Air Source Heat Pumps & Underfloor Heating

Underfloor heating can provide a very effective heating solution when paired with an air source heat pump.

Underfloor heating can be used alongside, or instead of radiators in a home but is more suited for the lower floor of a home due to construction materials used. Underfloor heating on a lower floor is often paired with radiators on upper floors as part of an air source heat pump heating system.

Underfloor heating works as part of a central heating system and therefore must be used with the air to water heat pump type.

An installer will be able to design a heating system where underfloor heating can potentially be used alongside an air source heat pump in your home.

Further Reading

Parts Of An Air Source Heat Pump Explained

Pros & Cons Of Air Source Heat Pumps

Do You Need A Hot Water Tank With An Air Source Heat Pump?

How Air Source Heat Pumps Can Work In Winter