Where To Install An Air Source Heat Pump

Air source heat pumps extract the heat from outside air for use in a home and so proper placement of outdoor heat pump units is important for maximum heat gains and efficiency.

Outdoor air source heat pump units should always be placed in an area with plenty of space for fresh air. Air source heat pumps are often installed down the side of houses and placed on a concrete slab on the ground, while being close enough to a property for the associated pipework.

An air source heat pump will be more efficient and can cost less money to operate when installed in the right location.

Our air source heat pump is located down the side of our house adjacent to the garage and was located and installed in line with the manufacturer’s guidelines.

Air Source Heat Pump
Our air source heat pump installed on the side of our house

The remainder of our heating apparatus is located indoors.

We discuss throughout this article the things to consider when choosing where to install an air source heat pump and why our heat pump is located where it is.

Factors That Influence Where To Place An Air Source Heat Pump

The location of an air source heat pump (ASHP) can depend on several factors, including the annual temperatures and outside characteristics of your landscape.

Overall Climate

Most air-source heat pumps function best when placed out of direct sunlight because the hot sun can reduce the efficiency of the unit to cool and heat your home.

Our air source heat pump is located down the side of our house and is only in direct sunlight for a small portion of the day.

Air Source Heat Pump & Air Conditioning Units
This location for our heat pump (right) is out of direct sunlight for most of the day but still in an area with sufficient airflow

If you live in a snowy climate, it is best to place an air source heat pump out of the drifts. Since the heat pump draws air from all sides, snow and ice will hinder the air flowing into the unit.

Ease of Maintenance

How easy will it be for a technician to access the unit for repairs? They need plenty of space on all sides to inspect and repair the outdoor unit.

Our heat pump is installed on concrete supports with enough space on all sides for maintenance and servicing access.

Air Source Heat Pump Pipes
Space behind our heat pump for access and maintenance, as well as for the pipework

Keep leaves and branches cleared away from the unit and ensure the grass does not grow tall there. Keeping the space around the air-source heat pump clean can maintain efficient function and accessibility for repairs.


Because a heat pump relies heavily on fresh air to work well, you should have it installed in a well-ventilated area outdoors.

A garage or other enclosed space won’t provide the ample airflow needed for an air source heat pump to work effectively.

Our ASHP is located in the open air and isn’t closed off behind walls or fences, which could impact the efficiency of the unit.

Air Source Heat Pump
If an air source heat pump isn’t located in an open area then it can hinder it’s ability to extract heat from the air

An experienced technician will know to place the unit outdoors in a place that allows for plenty of ventilation from all sides. Anchoring the heat pump on a concrete pad reduces vibration and allows for proper drainage.


Although air source heat pumps are relatively quiet during operation, the can get a bit noisier when temperatures are lower because they’re having to work harder.

This noise will need to be considered when looking to install an ASHP near neighboring properties.

See our article on air source heat pump noise for more information.


Below are the installation location requirements for our particular model of air source heat pump.

The outdoor installation requirements for our air source heat pump taken from the manual. Copyright Mitsubishi Electric.

The most important factors were ensuring that the heat pump was located out of direct sunlight, away from neighboring properties and where both power cables and pipework could be easily available and accessible.

Installing out air source heat pump down the side of the house was the most sensible solution.

Can You Install An Air Source Heat Pump Yourself?

Installing an air source heat pump isn’t a do-it-yourself job. The purchase of a heat pump is significant, and you want expert installation to guarantee the system will work as desired for many years.

What Happens When Installing A Heat Pump?

Since an air source heat pump is a complex appliance, you’ll need to choose the right model to heat your home. Once a heat pump is up and running, you only need to worry about learning how to use your new heating and air conditioning system.

Before installation, a professional heat pump technician will come to your home and assess the square footage of your structure to ensure the proper heating and cooling unit size.

Many air-source heat pump companies will install the indoor units first:

  • For an air to air ductless system, they’ll locate a spot in the house to attach the heat pump to a wall. This must be where the unit can get air to heat and cool your home.
  • For an air to air ducted system, the installer will most often locate the indoor unit in the attic to tie into the ductwork.

See our article comparing ducted vs ductless air source heat pump systems for more information.

  • For air to water heat pump systems (like ours), apparatus such as a hot water cylinder (if required) will be installed inside the house, such as in a cupboard.
Air Source Heat Pump Water Heater Tank
The cupboard inside our house where all the indoor apparatus is located

See our article on using an air source heat pump with a hot water tank for more information.

Once the assessments are completed, installing the pump requires the following steps:

  1. The installer will drill a hole in the wall where the indoor and outdoor units can connect. This opening will allow the electrical connection and the refrigerant line to tie to the outdoor unit.
The refrigerant pipes heading into our house
  1. Most homes will have the outdoor unit sitting on a prepared concrete slab. This concrete slab should be out of the direct sun and away from trees and shrubs to prevent airflow obstruction.
  1. Once the electrical and refrigerant lines connect the two units, the refrigerant lines will be insulated to protect the flowing heated or cooled refrigerant.
  1. You’ll need a thermostat to connect to the system. The installer will confirm that the technology works appropriately to regulate the air-source heat pump.
Air Source Heat Pump Water Heater Control Panel
The control panel for our air source heat pump system

Where To Install An Air Source Heat Pump

The placement of an air source heat pump can influence how effectively and efficiently it works.

Outdoor air source heat pump units are typically installed in an open area out of direct sunlight, but close enough to a house to keep away from neighboring properties and for pipework and cables to be accessible.

The actual location of an ASHP will differ between installations and must be in line with the manufacturers and any local or national guidelines and regulations.

Further Reading

Air Source Heat Pump Installation Requirements

How An Air Source Heat Pump Works

Parts Of An Air Source Heat Pump Explained

Air Source Heat Pumps & Underfloor Heating

Air Source Heat Pumps & Radiators

Air to Air vs Air to Water Heat Pumps