An air to air heat pump is the same equipment most people call split air conditioning: an indoor unit on the wall or ceiling, an outdoor unit outside, and refrigerant pipework between them. It heats in winter and cools in summer. When people ask what one costs, they are really asking two questions: what the installation involves for their particular rooms, and what it will cost to run once it is in.
This guide works through both. It is about air to air systems specifically; for the wider picture of what goes into any air conditioning installation, our installation cost breakdown covers the general categories of work.
The six things that shape an installation quote
Work through these in order and you will understand most of the difference between one proposal and another.
- 1
Number of rooms
Each room you want heated and cooled normally needs its own indoor unit. One room is a single installation; four rooms is a different project with more equipment, more pipework and more labour.
- 2
Single split or multi-split
A single split pairs one indoor unit with one outdoor unit. A multi-split serves several indoor units from one outdoor unit, which saves wall space outside but needs a larger outdoor unit and longer, more carefully planned pipe runs.
- 3
Unit size
Output is matched to each room's heat gains and losses. A larger room, a glazed extension or a loft room under the roof needs more capacity than a small bedroom, and larger units cost more.
- 4
Pipe run length and route
The further the indoor unit is from the outdoor unit, the more pipework, insulation and trunking are needed. Routes through several walls or across a loft add time.
- 5
Outdoor unit position
Ground-level positions on a flat wall are simplest. Brackets high on a wall, flat roofs or positions needing access equipment add work, as do any anti-vibration mounts chosen to keep noise down.
- 6
Electrical supply
Most systems need a dedicated circuit from the consumer unit. The condition of your consumer unit and the distance to the outdoor unit affect what is involved.
Finish and visibility
How tidy the installation looks also affects the scope. Surface trunking on an outside wall is the most common approach. Running pipework inside walls, behind units or through floor voids looks cleaner but takes longer, and is easiest during decorating or building work. Condensate drainage needs a route too; in heating mode the outdoor unit also produces water that should be taken somewhere sensible rather than left to drip onto a path.
Concealed ducted systems are a separate category. They hide the indoor unit in a ceiling void and feed rooms through grilles, which involves more design and building work than wall-mounted units.
Running costs compared with gas heating, in principle
A heat pump does not burn fuel. It uses electricity to move heat from the outside air into the room, and in normal conditions it delivers more than one unit of heat for each unit of electricity it uses. A gas boiler, by contrast, turns the gas it burns into heat at a little under one-to-one.
Whether the heat pump is cheaper to run therefore depends on two numbers: how efficiently it is working, and the price you pay for electricity compared with gas. Efficiency falls as the outside temperature drops, and electricity usually costs more per unit than gas, so the gap between them is what matters. Your own tariffs, how well the room holds heat and how you use the system all shift the answer.
A practical way to think about it: an air to air heat pump is often a cost-effective way to heat the specific rooms it serves, such as an extension, a home office or a loft room the boiler struggles to warm, while the boiler continues to provide hot water and heat elsewhere.
Questions to ask before comparing quotes
- Which rooms does each proposal cover, and with what size of unit?
- Is it a single split per room or a multi-split?
- Where will the outdoor unit and the pipe routes go?
- Is the electrical work included?
- How is condensate drained from both indoor and outdoor units?
- Is commissioning and the F-Gas paperwork included?
Questions people ask
Are air to air heat pumps cheaper to run than gas?
It depends on how efficiently the heat pump runs in your conditions and on your electricity and gas prices. A heat pump delivers more heat than the electricity it uses, but electricity usually costs more per unit than gas, so the result varies between homes and tariffs.
What affects the cost of an air to air heat pump?
Mainly the number of rooms, whether you choose single splits or a multi-split, the unit sizes, the length of the pipe runs, the outdoor unit position and the electrical work required.
Is the survey free?
Yes. We offer free in-home design and a quote, with a fixed price in writing for the agreed installation.
The cheapest system to buy is not always the cheapest to own. A unit sized correctly for the room, in a sensible position, is what keeps both the installation and the running costs predictable.