GreenGenUK has been installing air source heat pumps since 2011. As such, we’ve seen and heard just about every question relating to air source heating. Below we clear up some of the most common air source source questions.

An Ultra Quiet Mitsubishi Ecdodan air source installation.

Will air source provide all of my heating and hot water?

Yes. A correctly specified air source heat pump will provide all of a home’s space heating and hot water demand.

In GreenGenUK’s opinion, design and specification of air source heating system is the most important stage.

Does an air source unit require maintenance?

To be compliant with RHI regulations and warranty implications, air source heat pumps require annual servicing.

GreenGenUK offers a variety of servicing options. However, our lowest cost service package starts at £150. This includes a full annual service.

Where do I site my unit?


Air source uses the residual heat in the air to produce space heating and hot water. Therefore, the unit needs to be sited externally.

With this in mind, it’s largely up the customer where the unit is situated. It’s important to consider how you connect the unit into the building and the distance of any pipe runs. Typically, an air source heat pump sits adjacent to an external wall.

Is an air source heat pump noisy?

Like all heating systems, air source heat pumps have a level of noise output.

The actual noise output of a heat pump depends on the size and model of the heat pump. GreenGenUK works with Mitsubishi Ecodan heat pumps. The Ecodan is Quiet Mark Approved. Mitsubishi Electric’s website has more detail on the noise output of their units.

The noise output of air source is similar to that of an oil or gas boiler.

Do I need new radiators?

Air source heat pumps work with lower flow temperatures than fossil fuel heating systems. Because of this, it’s important to consider the size and output of the radiators in the system.

The size and demand of the room dictate whether a radiator needs replacing. Generally, units in the primary living spaces are most commonly in need of replacing.

Additionally, you can reuse the majority of radiator pipework.

Do I need planning permission to install air source?

Air source heat pumps fall under Permitted Development Rights.

As such, air source requires no planning permission. There are exceptions to this, such as AONBs and Listed Buildings. GreenGenUK advises when planning consent is a requirement.

What is a SCOP or SPF?

The rating of a heat pumps’ efficiency referred to as a SCOP (seasonal coefficient of performance) or SPF (seasonal performance factor). They take into account both space heating and hot water efficiencies over the course of a year.

For example, an 8.5kW Ultra Quiet Mitsubishi air source unit will achieve a SCOP or SPF of 4.05. In effect, this is stating that the unit outputs 4.05 units of heat for every one unit of electricity consumed.

You can search for a product and its SCOP or SPF on the MCS Product Search website.

Got a question we haven’t covered?

Is the answer to your query not in our list of common air source questions or are you looking for further information?

Our air source page has lots of info on our air source and is a good place to start. Click here to visit our air source page.

Give us a call or complete the enquiry form found at the bottom of the page and we’ll come back to you.