Are heat pumps worth the investment?

I’m sure I’m not alone in saying that the UK economy is dealing us something of a rollercoaster ride. It shot up, crashed down, flipped upside down, and continues to make everyone feel disorientated and somewhat nauseous.

My GB Home Surveys Gloucestershire team and I have seen this in every aspect of life. It’s been especially manifested in the property sector.

You will undoubtedly have heard of heat pumps, especially over the past few years, as energy efficiency and carbon footprints have increasingly become the public’s focus.

On this page, I’ve compiled things to know about heat pumps and how to decide if they’re worth the investment. In short, it depends on your property or the property you’re looking to buy.

What are heat pumps?

A heat pump sounds like a fancy brand-new technology. In reality, they have been around for a long time. They can be found in various household applications, including fridges, freezers, air coolers and air conditioning systems.

Without going into too much detail, the compressed refrigerant within such appliances travels within a closed system. The heat within the device is absorbed into the refrigerant, which cools the air and anything near to or in contact with it.

Modern refrigerant systems are much more efficient than even a decade ago. Technology has developed over the years to improve refrigerants, the electronics that control the systems and, where relevant, the insulation to maintain controlled temperatures.

What’s this got to do with heat pumps to heat my home?

These systems use the warmth collected for heating properties and sometimes hot water. Depending on the setup, the refrigerant can extract heat from the air, the ground and – in some cases, although not common in the UK – a water source like a stream or a pond.

They can often also be used in a system for cooling a property (but we’ll stick with heating on this page).

If these heat pumps are specified correctly and installed in suitable properties, they can be very efficient.

Types of heat pump

So, what types of heat pumps are commonly available in the UK?

Air-to-water– the heat pump system removes heat from the external air (even on freezing days) and transfers that heat into the water used for heating, such as a wet underfloor heating system, and sometimes to heat hot water.
Air-to-air– heat is removed from the external air and transmitted via a refrigerant to a heating matrix. A fan blows over the heating matrix to transfer that warmth into a room.
Ground-source– heat is collected from the ground, either from a long coil of underground pipe or a vertical pipe within a borehole. This heat is then transferred into the water used for heating, and sometimes hot water. Below a certain depth, the heat within the ground is very consistent. This is an advantage when specifying systems.
Water-source– heat is collected from water sources such as streams. It’s transferred via the refrigerant in the pipework to the property. Here, it’s used for heating, again typically wet heating systems such as underfloor heating. These heat pumps aren’t common in the UK, but they would be an option for some rural properties like we find in Gloucestershire.

So why aren’t we all swapping our gas boilers for heat pumps?

Well, the decision isn’t as straightforward as it might seem.

For the heat pumps to work efficiently, they generally need two criteria:

The property being heated needs to be very well insulated – floors, walls, windows and roof – and reasonably airtight, all of which reduces heat loss from the property.
A heating system that doesn’t require high temperatures, such as underfloor heating, operates at much lower temperatures than a system with radiators.

In the rest of this article, I’ll explore the pros and cons of heat pumps by answering some common questions.

Are they really efficient?

Well, yes, and no.

They are very efficient with the correct system specification and a suitably insulated property.

But what does ‘efficient’ mean? It means the amount of usable heat per kilowatt of energy used.

These systems can be far more efficient than gas-fired central heating systems (i.e. more heat per kilowatt). However, let’s not forget that the electricity needed to operate the pumps is far more expensive to buy than natural gas.

If the systems are installed in older, less insulated properties, the heat pump will need to operate for extended periods. That makes it less efficient.
Higher-than-recommended heating water temperatures are required if the heat pump is connected to a radiator system. This, again, will make it less efficient. To be efficient, heat pump systems should require less than 40°
In some cases, it’s necessary to replace radiators with significantly larger ones to operate at more suitable lower temperatures.
If you want the heat pump to heat domestic hot water (usually at a higher temperature for safety reasons), the heat pump will be less efficient.
If the property is significantly extended after installing a heat pump, the additional space may result in it operating for longer periods to maintain a comfortable temperature.

As you can see, calling a heat pump ‘efficient’ involves more factors to do with the property than the device itself.

Is there room outside for the heat pump to be installed?

A heat pump can be heavy, so there needs to be a suitable outside location to site it. They don’t take up too much room, all things considered. However, outside space is often a premium in tiny city houses.

Some units can be mounted on a wall on brackets. Either way, it may be necessary to get planning permission. (At the moment, planning permission for a heat pump should be easy to get.)

Is there room inside the property for the indoor unit?

These units are often the size of a wall-hung gas boiler. You will need space in a location which isn’t too far away from the outside heat pump.

Noise

Yes, the fans on the external heat pump units can be noisy, especially on ‘budget’ systems generally designed to maximise profits for the installer.

Do your research and find out what noise would be emitted by a unit before you purchase it. If you get it wrong, you might find that your friendly neighbours are no longer quite as pleasant as they once were.

In a rural location, the noise may also interfere with that peaceful evening sitting on the patio under the stars.

That said, of course, all new condensing gas boilers also emit periodic noise from the flue fan.

Government grants

Currently, the Government is offering a £5,000 grant towards the installation of air-to-water heat pumps and £6,000 towards ground source heat pumps.

That’s significant, but the total installation cost for any heat pump is generally far higher than a gas, LPG or oil-fired boiler.

You can expect to pay around £12,000 for a simple air-to-water system and at least double that for a ground-source heat pump system.

Even with the Government grant, you’ll still be paying much more than you would for a traditional boiler.

So – what’s my opinion on whether heat pumps are worth the investment?

Simple – in the right property with the correct specification, such systems are excellent.

However, if the system is already installed in a property you want to buy, ask for the electricity bills for the last twelve months. This gives you an idea of ongoing costs through the four seasons – you may be surprised, even shocked.

When you analyse the bill, remember that electricity was much cheaper twelve months ago. Add up the kW hours used throughout the year and multiply it by the current unit cost.

Here’s the long and short of it:

If you want to install a heat pump heating system in your existing property or a property you’re looking to buy, get a heat pump engineer (not a salesperson) to give you impartial advice.
If a property has a relatively new (within five years) natural gas-fired boiler with modern radiators and a modern hot water cylinder (or a combination boiler), it may cost less to run than an efficient heat pump.
If your property is in a rural location or off the natural gas grid, the benefits of changing your old LPG or oil-fired boiler to an electric-powered heat pump may be more tempting – assuming the property is well insulated (or will be).

Making the decision at the right time

At some point in the near future, there will be increased pressure to get rid of your natural gas, liquid petroleum gas or oil-fired boiler and install an electric heat pump system. Do your homework and make that decision wisely, at the right time for your pocket.

Of course, it’s not all to do with money out of your pocket. There is also the environment to consider. It’s good to think that there are no harmful local emissions from operating a heat pump.

So, is it currently worth the investment? If you’re at a stage in the property maintenance cycle where the existing gas, LPG or oil-fired heating system needs replacing, then certainly consider the heat pump investment. However, don’t expect to save real cash out of your pocket for a long, long time.

For more advice on purchasing a property, consider instructing a Gloucestershire chartered surveyor. As well as inspecting and creating a detailed report of the property’s overall condition and value, we can also arrange for specialist engineers to conduct thorough inspections and testing of the specific heating system.

You can reach me or other members of my team using the form below. Alternatively, you’ll find my details on the Locations page. I can’t wait to hear from you.

James Quinn, AssocRICS