Air Source Heat Pumps

Air-to-water heat pumps are suitable for many types of homes and are the most common type of domestic heat pump, with tens of thousands of installations across the UK. However, there are a few things you should consider before deciding whether a heat pump is right for you.

You’ll need a place outside your home where a unit can be fitted to a wall or placed on the ground. It must have some space around it to allow a good flow of air.

There are two types of air-to-water heat pumps: monobloc and split systems. A monobloc system has all the components in a single outdoor unit, with pipes carrying water to the central heating system and a hot water cylinder inside your home. A split system separates the components between indoor and outdoor units. Whether a monobloc or split system is right for you will depend on your budget and the space available.

Monobloc systems tend to be cheaper and quicker to install and don’t take up as much space in your home, although they are generally slightly less efficient than split systems. The efficiency gain from split systems comes from some of the heat transfer taking place inside the building where it is warmer, resulting in less heat being lost.

If you’re not limited by space inside your home, it may be worth the extra cost of installing a split system. Your installer should be able to talk you through your options and help you choose the design that works best for you.

The external unit for a heat pump is identical for both monobloc and split heat pumps. Noise is created by large fans moving air across the heat exchanger.

Unless the heat pump is working very hard (ie in cold weather or producing high temperature water), you can expect the noise to be a similar volume to a fridge, if you were standing within a couple of metres. You could easily hold a normal conversation next to it, without raising your voice. As it gets colder outside, this noise will increase while it’s operating, but should still allow you to hold a conversation easily, only raising your voice a little.

The inside unit for a split system only contains valves and pumps and makes very little noise at all.

A standard heat pump doesn’t provide hot water on demand like a combi boiler, so you will need a way of storing hot water for when you need it. The size of hot water cylinder required will depend on the amount of hot water that your household typically uses, but the cylinder can usually be fitted inside any cupboard that measures around 80x80cm.

The cost of an air-to-water heat pump varies depending on the size of heat pump, the size of the property, whether it’s a newbuild or an existing property, as well as whether you need to change the way you distribute heat around your property. Typical costs are around £7,000 to £13,000, and we recommend speaking to at least three installers to provide a quote for your heat pump system to give you the best idea of costs for your home.

Running costs will depend on how your heat pump is designed and how it is operated. Savings on your energy bill will also depend on the system you are replacing.