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Air Source Heat Pumps

Are you interested in getting an air-source heat pump installed in your home or premises? Don’t delay, call Gregor today on 0117 935 2400 or 01225 738 397 and ask to speak to our Renewables team.

What is an Air-Source Heat Pump (ASHP)?

The Air-Source Heat Pump is a device that uses energy in the air to boil a refrigerant by passing air across an evaporator. The heat pump looks very similar to a traditional Air Conditioning unit.

What types of Air-Source Heat Pump do Gregor install?

There are two types of air-source heat pump that are quite distinct in how they operate: air-to-water heat pumps, and air-to-air heat pumps. We will look at each of these in turn below.

Both types of Air-Source Heat Pumps can help you to save on your energy bills and reduce your carbon emissions.

1. Air-to-Water Heat Pumps

Air-to-water heat pumps work by heating up water which is then circulated through your central heating system, releasing its heat gradually into your house via underfloor heating pipes and / or radiators.

Air-to-Water Heat Pumps are themselves available in two different configurations: Monobloc and Split system.

Monobloc heat pumps

he whole heat pump is enclosed within the casing. The heat pump is generally fitted on an outside wall with clear air flow across it. It can come in various power outputs; and some models are single-fan units while others are twin-fan units.

The unit is fitted onto rubber feet. Twin 28mm Flow and Return pipes enter the building and connect into the central heating system.

Split system heat pumps

The system is split with the outdoor evaporator being connected to the indoor unit with two pipes, one for gas refrigerant and one for liquid refrigerant. The outdoor unit can be located up to 20m away from the indoor unit. These systems are desirable if the customer doesn’t want the evaporator near the house or doesn’t have any suitable space. We only install split system pumps that use the latest environmentally-friendly refrigerants.

What makes of Air-to-water heat pump do Gregor install?

We install air-source heat pumps by Daikin and Mitsubishi. There is further information below. However, if you would like to find out more, don’t delay, call Gregor today on 0117 935 2400 or 01225 738 397.


Gregor install Daikin split systems. Daikin have considerable experience in the commercial heating and cooling market, from which the domestic product has been developed.

Daikin offers a range of sizes from 4kW to 16kW. Gregor are a premier installer for Daikin and can offer a comprehensive 5-year warranty on the Daikin products.

To heat domestic hot water, Daikin offers a range of cylinders including integrated cylinders and indoor units. These offer an aesthetically pleasing appearance and are a good solution where space is at a premium. They look similar to a white goods product such as a fridge-freezer.


Gregor install both types of system and only use leading brands. For the monobloc systems, which make up around 80% of our installations, we use Mitsubishi. These come in a range of sizes from 5kW to 14kW. Gregor are a premier installer for Mitsubishi and so can offer a comprehensive 5-year warranty on the product.

To heat domestic hot water, a heat pump cylinder is fitted. We prefer to install the Mitsubishi pre-plumbed cylinder with the heat pump. These come in a range of sizes from 150 litres to 300 litres. Solar heat pump pre-plumbed cylinders and slimline variants are also available.

Heat Pump Installation Enquiries

Interested in having a Heat Pump fitted at your property? Fill in our Heat-Pump Pre-Survey Questionnaire today, and one of our renewables surveyors will get back to you soon!

2. Air-to-Air Heat Pumps

Air-to-Air heat pumps instead let you use the natural heat in the outside air to directly heat the indoor air circulating around your home.

The typical installation is electrically powered and consists of a wall mounted outdoor unit linked to an inside unit similar to an air conditioner. These units contain a refrigeration circuit that absorbs heat from the outside air before amplifying and distributing it to heat the air in your home.

Many Air-to-Air Heat Pumps can also work in reverse to cool the air in your home as well.

Planning permission is not usually required although this should be checked with your local authority. Multiple units can be installed when necessary and their relatively smaller size makes them particularly suited to apartments, smaller homes and conservatories.

A key feature of an Air-to-Air Heat Pump is its ability to generate more energy to heat your home than is required to power its operation. Efficiencies of 300% can be observed with 1 kWh of electricity powering the pump generating 3 kWh of energy to heat your home.

Air-to-Air Heat Pumps are more likely to be a good choice if your home is well insulated. Good levels of roof, floor and wall insulation are all desirable, as are double-glazed windows.

Government Grants

The Boiler Upgrade Scheme (BUS) offers UK homeowners government grants of up to £5000 towards the initial installation cost of Air Source Heat Pumps, subject to eligibility criteria being met. The chief criterion is to have a valid EPC certificate whose home insulation recommendations have been implemented. Applications can only be made for installations that commenced on or after 1 April 2022. The opening date for applications in 23 May 2022. BUS has replaced the Domestic Renewable Heat Incentive Scheme (DRHI), which closed to new applicants on 31 March 2022.

Our Services

Contact us for more!

Are you interested in getting an air-to-air heat pump installed in your home or premises? Don’t delay, call Gregor today on 0117 935 2400 and ask to speak to our Renewables team. We look forward to discussing your heat pump needs with you and to booking you in for a survey if you would like one!

Why use Gregor for my Air-Source Heat Pump Installation?

Our experienced team of MCS-accredited installers has been installing air-source heat pumps for over 10 years. With Gregor, you are in safe hands, as we have the expertise needed to cover all aspects of the design, installation and servicing of your heat pump. We are also proud of our high standards of customer service, and we are a very well-established and financially stable company, so you can count on us to be here to serve your needs for maintenance and servicing far into the future.

If you are interested in getting an air-source heat pump installed in your home or business premises, don’t delay, call Gregor today on on 0117 935 2400 or 01225 738 397 and ask to speak to our Renewables team. We look forward to discussing your heat pump needs with you and to booking you in for a survey if you would like one!

Save on your energy bills

Installing an Air-to-Air Heat Pump can help you to reduce your monthly energy bills depending on your current system and the other options open to you. Savings are more likely if you do not have access to mains gas. Savings are unlikely to be possible if your home is not well insulated.

Air Source Heat Pumps Case Study

Bristol Zoo Gardens

Bristol Zoo Gardens is the fifth oldest zoo in the world. Located in the heart of Bristol, it works to create a sustainable future for wildlife and people, with conservation at the heart of everything it does.

Bristol Zoo Gardens needed an energy- efficient way of heating their new lemur enclosure, that would keep the lemurs warm and cosy whilst having the minimum impact on their living space and visitors viewing enjoyment.