A straightforward guide to how heat pumps work, the type of property they suit and the questions to ask before making the switch.
Air source heat pumps are becoming an increasingly familiar sight outside UK homes, but deciding whether one is right for your property isn’t quite as simple as swapping one heating appliance for another.
A heat pump can provide an efficient, lower-carbon way to heat a home, but good design is crucial. The property itself, its heat loss, radiators or underfloor heating, hot-water requirements and even the way you like to use your heating all need to be considered.
So before deciding whether to make the switch, it helps to understand what you’re actually buying.
How does an air source heat pump work?
An air source heat pump takes heat energy from the outside air and uses it to heat your home.
Even when it feels cold outside, there is still heat energy available in the air. The heat pump captures this energy, raises its temperature using a refrigeration cycle and transfers it into your heating and hot-water system.
Unlike a traditional boiler, which generates heat by burning fuel, a heat pump moves heat from one place to another.
Because of this, a correctly designed heat pump system can deliver more heat energy to your home than the electrical energy it consumes.
Are heat pumps suitable for older homes?
They can be.
There’s a common misconception that heat pumps are only suitable for brand-new, highly insulated properties with underfloor heating. In reality, they can work successfully in many different types of home.
What matters is understanding how much heat the property loses and designing the system accordingly.
Insulation and draught-proofing can reduce the amount of energy needed to keep a home comfortable, so improving these areas may be worthwhile before or alongside a heat-pump installation.
But the age of a property alone doesn’t determine whether a heat pump will work.
Do you need underfloor heating?
Not necessarily.
Underfloor heating can work particularly well with heat pumps because it operates effectively at lower water temperatures, but heat pumps can also work with radiators.
Some existing radiators may already be suitable. Others might need to be replaced with larger or higher-output models to provide enough heat at the lower flow temperatures typically associated with heat-pump systems.
This is one of the reasons a proper room-by-room heat-loss calculation is so important.
Simply installing a heat pump without considering the rest of the heating system can lead to disappointing results.
Will a heat pump keep my house warm in winter?
A correctly designed system should be capable of maintaining the required indoor temperature during cold weather.
The experience can, however, feel different from traditional boiler heating.
Heat pumps generally work most efficiently by maintaining a comfortable, relatively steady temperature rather than repeatedly delivering short bursts of very hot water to the radiators.
Good system design, correct controls and understanding how best to operate the system all make a difference.
What happens to my hot water?
If your current boiler provides instantaneous hot water, switching to a heat pump may mean changing the way hot water is stored and produced.
Many heat-pump installations use a hot-water cylinder, so available space and your household’s hot-water demand need to be considered during the design process.
A household with several bathrooms and high hot-water usage will have different requirements from a smaller property occupied by one or two people.
Again, this is why there isn’t a one-size-fits-all heat-pump package.
Where does the outdoor unit go?
An air source heat pump requires an outdoor unit with good airflow around it.
Its position needs to be considered carefully, taking account of practical access, appearance, noise, pipe runs and the layout of the property.
The best position isn’t necessarily simply the least visible corner of the garden. Location can affect both the installation and how well the system operates.
What about running costs?
There isn’t a sensible single answer to the question, “Will a heat pump save me money?”
Running costs depend on the efficiency of the system, the property’s heat demand, electricity prices, the heating system being replaced and how the household uses its heating and hot water.
A well-designed system operating at suitable temperatures can be very efficient. A poorly designed or incorrectly operated system may perform very differently.
We’d therefore be wary of anyone promising a particular saving without first understanding the property.
What should I ask before choosing a heat pump?
Before committing to an installation, make sure you understand how the proposed system has been designed.
Useful questions include:
- Has a room-by-room heat-loss calculation been carried out?
- Will any radiators need changing?
- What flow temperature has the system been designed around?
- Where will the outdoor unit and hot-water cylinder be located?
- How will the system provide your household’s hot water?
- What controls will be installed?
- What servicing and maintenance will be required?
- Are there any suitable grants or incentives available?
- What warranties apply to the equipment and installation?
You should come away understanding why a particular system has been recommended for your home, rather than simply being given a model number and a price.
So, is a heat pump right for your home?
For many properties, an air source heat pump can be an excellent option. For others, improvements or changes to the existing heating system may be advisable first.
The important part is not starting with the assumption that you either must or mustn’t have one.
At Adam Worgan Ltd, we believe the starting point should be the property itself. By looking at your home, existing heating system and how your household uses heat and hot water, we can help you understand the options and whether a heat pump makes sense for you.
Considering an air source heat pump? Get in touch with our team to discuss your home and the options available.
