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Heat pumps are an energy efficient and low carbon way to heat your home. They are suitable for almost all types of homes and may save you money on your energy bills. 

Heat pumps gained popularity in the 1970’s however have been around for over 150 years,  and are steadily gaining popularity in the UK. Heat pumps will play a crucial part in helping Arran and Scotland achieve their net zero targets. 

What is a heat pump? 

The low carbon system takes heat from the outside environment and raises the temperature to use in your central heating system. It uses electricity to do this but for every unit of electricity it uses, it produces three units of heat thus making them a very efficient alternative to oil. They also produce much less CO2 emissions than other heating systems. 

Heat pump efficiency 

The efficiency of a heat pump depends on the ‘source’ temperature. The colder the source temperature, the harder the heat pump needs to work. As Arran is situated in the Firth of the Clyde, and has a mild climate resulting from its location on the Gulf Stream, this combined provides a relatively stable source of heat throughout the year, allowing the heat pump to extract heat efficiently even during colder months, resulting in better energy efficiency and lower operating costs compared in inland locations where the temperature fluctuates more drastically.  

What are the types of heat pumps? 

Air Source (air to water)

Commonly known as an Air Source Heat Pump or ASHP transfers heat from outside to the water in your central heating systems. The fluid passes through a compressor which raises the temperature and transfers the heat to your central heating system. This is then used to heat your home via radiators and can be stored in a hot water cylinder to be used for hot taps, showers and baths. 

Benefits 

1. Lower energy bills – A correctly installed ASHP can save you money on your energy bills. 
2. Reduce energy usage – Heat pumps are three times more efficient than traditional fossil fuels based heating systems. 
3. Improve your carbon footprint – As they dont use fossil fuels because they take heat from the environment, your CO2 emissions are lower. 
4. No more fuel deliveries like oil, LPG, gas bottles or wood.
5. Generally low maintenance.

Types 

• A monoblock system is the more common system as they are cheaper and quicker to install. A monoblock system has all the components in a single outdoor unit. Pipes then carry water to the central heating system and hot water cylinder inside. 
• A split system is more efficient because some of the heat transfer takes place inside the building where it is warmer, resulting in less heat loss. The split system separates the heat into indoor and outdoor units. 

How much does it cost to install a heat pump? 

The typical costs of installing an ASHP varies depending on: 

• The side of heat pump
• The size of the property it is being installed in 
• The age of the property 
• Whether you need to upgrade your radiators. 

The average cost is around £14,000, however some funding or grants may be available. 

Funding

Some funding or grants may be available.  See our funding information here. Whilst we cannot make recommendations directly, you can find a list of accredited providers who have provided services to Arran here.

Ground Source Heat Pumps (ground to water)

A ground source heat pump transfers heat from the ground outside to heat your home. It can also be used to heat water stored in a hot water cylinder, which can be used for your hot taps and showers. 

To make it work, you install a loop of pipe in your garden. You can either bury this loop in trenches or install a long pipe via a borehole. The pipe contains a mixture of water and antifreeze, known as a thermal transfer fluid (TTF) or ‘brine.’

The brine absorbs heat from the ground and passes it through a heat exchanger into a refrigerant. The refrigerant is then compressed, raising its temperature, before transferring the heat to your central heating system.

Benefits

1. Lower energy bills – A correctly installed heat pump can save you money on your energy bills as they are more efficient. 
2. Reduce energy usage – For every unit of energy they use, a heat pump generates three units of heat. 
3. Improve your carbon footprint – As heat pumps are a low carbon heating system, they emit less carbon dioxide emissions than other fuel sources. 

How much space is needed? 

You’ll need an area of land near your home where you are able to dig trenches or drill boreholes. 

If you have enough space, you can have a ground loop system. If space is limited, it may be possible to drill vertical boreholes to gather heat, however this is more expensive, and larger homes may need more than one borehole. 

How much does it cost to install a ground source heat pump?

A ground source heat pump can cost around £28,000. The additional cost for the ground source heat pump installation comes from the external work in the garden, where either trenches or boreholes will need to be dug. 

Funding

Some funding or grants may be available.  See our funding information here. Whilst we cannot make recommendations directly, you can find a list of accredited providers who have provided services to Arran here.  

Air-to-Air Heat Pumps 

Air-to-air heat pumps transfer heat from the outside air into your home, increasing the indoor temperature. The system’s fan coil units, or ‘blowers,’ distribute warm air efficiently. These systems also provide cooling, similar to air conditioning. In the UK, smaller homes, such as flats and park (caravan) homes, use these heat pumps more often than larger properties. They are more popular in Europe, where they provide both heating and cooling benefits in warmer climates.

Key Considerations Before Installation

1. Space Requirements
   You’ll need an outdoor unit mounted on a wall or placed on the ground with enough space around it for proper airflow.
2. Heating Distribution
   Unlike traditional ‘wet’ heating systems that use radiators or underfloor heating, air-to-air heat pumps use blowers or ducted air systems. Blowers are mounted on walls, while ducted systems are typically hidden within ceilings.
3. Types of Systems
   • Single-head systems: One outdoor unit connected to one indoor blower, ideal for small homes or single-room heating.
   • Multi-head systems: One outdoor unit connected to multiple indoor blowers, suitable for larger homes.
   • Ducted systems: Hidden air ducts distribute warm air throughout the house, commonly used in energy-efficient homes.
4. Hot Water Heating
   Most air-to-air heat pumps don’t provide hot water, so you may need an alternative solution, such as an electric immersion heater, electric shower, or a model that includes water heating.

Cost and Efficiency

Running costs depend on system design and usage. While air-to-air heat pumps can be cost-effective, savings vary based on the heating system being replaced. Ask your installer for an estimate of running costs tailored to your home. 

Funding

There is currently no funding available for air-to-air heat pump systems as only heat pumps that provide 100% of heating requirements are eligible unless there is a technical reason why 100% of heating requirements cannot be met by a heat pump alone. Call Home Energy Scotland on 08088082282 for more information.

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