What Is a Heat Pump?
A heat pump is an energy-efficient system that transfers heat from the outside air into your home. Even when it’s cold outside, a heat pump can extract warmth from the air and use it to heat your home and hot water. Think of it like your kitchen fridge in reverse. Instead of cooling the inside, the outside air is cooled, and the heat extracted is transferred into your home via your emitters (radiators, underfloor heating, fan coil units, etc). Instead of burning fuel to generate heat, heat is simply moved from one place to another — making it a cleaner, greener alternative to traditional gas or oil boilers.
There are two main types of air source heat pumps: Air to Air and Air to Water. Each has different benefits depending on your home’s layout and your heating priorities.
How can a Heat Pump extract heat from cold air?
Even when the air feels cold to us, it still contains plenty of thermal energy. Absolute zero (The point at which air would contain no thermal energy at all) is thought to be around -273 degrees Celsius. Even the harshest UK winters aren't that cold! Sweden, Norway and Finland have the coldest climates in Europe, and yet these countries have heat pumps in around 40% of homes, the highest adoption of heat pumps in the world. Most modern heat pumps will still extract heat at -15 and below, and although of course efficiency improves when conditions are milder, a correctly specified heat pump is a reliable source of heating even in chilly conditions.
Air to Air vs. Air to Water
Air to Air Heat Pumps:
Commonly thought of as Air Conditioning, and primarily used for cooling in the UK, air to air heat pumps are becoming an ever more popular option for domestic heating in the UK. They draw heat from outside into a refrigerant, which then transfers the heat into your home through internal fan units. They boast the same, or sometimes higher co-efficient of performance as air to water systems, are often cheaper and less disruptive to install, and of course, they provide effective cooling for the hottest days.
One drawback is that air to air heat pumps don't currently qualify for the same government grants as air to water, although installations are often cheaper or comparable.
Another consideration is that most air to air systems don't directly provide hot water.
There are many alternative options for domestic hot water however, and twinning them with an air to air heating system can offer an excellent, effective and planet friendly solution for your home.
We believe air to air systems can be the perfect solution for many UK homes, and we're on a mission to raise public awareness of air to air as a domestic heating system option in UK homes.
Air to Water Heat Pumps:
Just the same as air to air systems, these heat pumps extract heat from the outside air. The key difference, is that the heat is then transferred into water via a plate heat exchanger inside the heat pump.
This water is then circulated through a wet central heating system (radiators or underfloor heating) and provide both space heating and hot water.
They're most efficient when running "low and slow", meaning they run for longer periods with low flow temperatures, for example 35-55 degrees Celsius as opposed to the typical 60-75 degrees you'd expect from a gas or oil boiler. This means they work best with larger radiators or underfloor heating.
They’re a popular choice for full-home heating as they can often be connected to an existing system, although this sometimes requires upgrades to radiators and pipework.
The main drawbacks are higher installation costs due to the need for system upgrades (larger radiators, larger primary pipework and perhaps underfloor heating installation), slower response time compared to air to air, and they don't typically offer cooling, although it can be achieved in certain circumstances.
If like most UK homes you currently have a wet central heating system, air to water heat pumps may be the solution for you.
Heat Pump Myths vs. Facts
❌ Myth: Heat pumps don’t work in cold weather
✅ Fact: Modern heat pumps are designed to operate efficiently even in sub-zero temperatures.
❌ Myth: They only work in new builds
✅ Fact: Heat pumps are suitable for both old and new homes, provided the property is properly assessed.
❌ Myth: Heat pumps are noisy
✅ Fact: Modern heat pumps are usually whisper quiet, and building regulations are in place to ensure they cause minimal noise pollution
❌ Myth: Heat pumps are new, unproven technology
✅ Fact: Heat pumps are essentially refrigerators, the technology is well established, and in fact the first known heat pump used for space heating in the UK was installed in 1945!
Which System Is Right for Me?
Choosing the right system depends on how your home is currently heated, the level of insulation, and how you use your space.
We’ll guide you through every step — from property surveys and heat-loss calculations to choosing the most suitable type of heat pump for your lifestyle and budget.
Still unsure? Get in touch for free, honest advice. We’re here to help you make the most informed choice for your home.