Heat pump systems explained: the complete guide
We all know that traditional domestic heating systems might not be the most sustainable or energy efficient way to heat our homes. That's why, in recent years, heat pumps have become increasingly popular. They're an innovative solution that uses naturally occurring heat, rather than relying on fossil fuels. This means fewer greenhouse gas emissions and improved air quality.
But how exactly do heat pumps work? What do you need to think about before buying one? What are the main advantages of heat pumps? We'll answer these questions and more in this Hive guide.
How do air source heat pumps work?
First up, let's get into the detail of how air source heat pump systems work.
An air source heat pump absorbs heat from outdoor air into a refrigerant – this is done by the large unit that sits outside your home.
Next, the refrigerant is compressed to raise its temperature before being flowed into an indoor coil.
Finally, the pressurised vapour then condenses back into a liquid, which goes through a heat exchanger to heat up the water for your radiators or underfloor heating.
What are the different types of heat pumps?
There are three main types of heat pump heating systems:
Air source heat pumps
Air source heat pumps extract heat from the outside air to provide heating and hot water. They're popular for being relatively compact and can potentially be used in a wide range of homes.
Ground source heat pumps
Ground source heat pumps work by extracting heat from the ground below the home using a buried system. They do need sufficient land for installation of a ground array or borehole—but once installed, they're unobtrusive.
Water source heat pumps
Water source heat pumps extract heat from nearby water sources like lakes or rivers. To use one of these systems your home will need to be close to a water source.
In all types of heat pumps, the heat transfer process takes place over four stages:
- evaporation
- compression
- condensation
- expansion
This process, known as the refrigeration cycle, is powered by electricity. But crucially, it doesn't need to use any form of fuel to create heat because the system simply absorbs heat that is already there.
If that sounds a bit overwhelming, don't worry. Our friends at British Gas offer a free home survey which will identify any changes you might need to make before you switch to a heat pump system.
Air source heat pump pros and cons
As with any heating system, there are several heat pump pros and cons. Let's look at the advantages and disadvantages.
Advantages of an air source heat pump
Energy efficiency
Heat pumps operate at an energy efficiency rate of 300%, meaning they produce around three times more energy than they take in.
Low carbon footprint
There's no onsite fuel burning in a heat pump. And, if powered by a renewable form of electricity, they are almost carbon neutral.
Grants to help with costs
In the UK, grants such as the government's Boiler Upgrade Scheme can help to significantly reduce the cost of installing a heat pump. You can read more about grants here.
Long lifespan
Under normal usage conditions and with regular maintenance, you can expect an air source heat pump to give you up to 20 years of service.
Works well with solar panels
Heat pumps only require electricity to run, so pairing them with solar panels can make your heating system extremely cost effective – and almost carbon neutral. Want to find out more about solar energy? Check out our in-depth guide here.
Minimal noise
Heat pumps only emit between 40-60 decibels – that’s about the same as a gas boiler. The unit is outside the home too, so you may not hear it at all.
Disadvantages of an air source heat pump
Higher upfront costs
A heat pump is going to be more expensive to install than a traditional boiler. That said, grants and other forms of support can bring that cost down.
Not suitable for all properties
Any air source heat pump system is going to require some outdoor space, and you need to allow room for adequate airflow around the unit, too.
Reliance on electricity
Because a heat pump needs electricity to operate, a power cut could result in your home having no heating. A back-up generator would be useful in these situations.
Property changes may be required
To work at their best, heat pumps need good insulation and larger radiators than standard.
Frequently asked questions
What do I need to consider before getting a heat pump?
Before installing an air source heat pump, there are a few factors to consider:
Climate
Heat pumps work well in cold weather, ideal for the UK. But areas with extreme temperature variations may require regular checks to prevent ice buildup.
Home Insulation
Effective insulation, like cavity wall and loft insulation, ensures maximum efficiency.
Space Requirements
You'll need outdoor space with clear airflow for the unit and some indoor space for additional equipment.
Costs
Installation costs vary but may be offset by the Boiler Upgrade Scheme grant. Running costs will also need to include electricity and maintenance.
Want to get into the detail? Check out our heat pump Installation guide.
Are heat pumps noisy?
Air source heat pumps are not noisy. They only emit a hum between 40-60 decibels – about as loud as the average combi boiler. The units are outside, so noise is minimal.
How do heat pumps compare with boilers?
Heat pumps are more efficient, have a longer life span, and are better for the environment than traditional gas boilers. But they do have higher upfront costs. Check out our heat pump vs gas boiler guide for more info.
Do air source heat pumps require much maintenance?
A good quality, well installed air source heat pump only requires standard maintenance – our friends at British Gas recommend annual servicing.
Can air source heat pumps provide hot water?
Yes! Air source heat pumps can indeed provide hot water to your home.
How long do air source heat pumps last?
A well-maintained air source heat pump will last around 20 years. Factors such as climate, servicing, and temperature fluctuations can affect that longevity.
Can I get an air source heat pump if I live in a flat?
Air source heat pumps can be installed in flats. However, there may be restrictions around space, noise, property type, and heat pump size that you'll need to consider.
Are heat pumps environmentally friendly?
Heat pumps are considered one of the most environmentally friendly ways to heat your home. They can significantly reduce carbon emissions and, if run on renewable electricity, are almost carbon neutral.
How efficient are heat pumps?
Heat pumps are highly energy efficient. In some cases, they can be up to three times more efficient than traditional heating systems such as gas boilers. You can get more information on heat pump efficiency in our detailed guide.
Do heat pumps require planning permission?
In most cases you won't need planning permission for a heat pump. That said, certain types of properties may have restrictions, so it's best to check first.
Do heat pumps need insulation or radiator changes?
To work most efficiently, air source heat pumps require good insulation and larger radiators than standard.
How do air source heat pumps work with radiators?
Much like a traditional gas boiler, an air source heat pump system heats water which then flows through your radiators (or underfloor heating). This, in turn, gives off heat which will warm your home.
What do I need to consider when using air source heat pumps with radiators?
It's worth noting that, to get the full benefits of an air source heat pump, you'll need to have larger radiators than with a traditional gas system.