Air and Ground Source Heat Pumps

Jowett and Jowett are MCS (Microgeneration Certification Scheme) accredited installers of Air Source Heat Pumps (ASHP) across the South West. 

Air Source Heat Pumps are designed to provide up to 100% of a property’s central heating and hot water demands by using electricity to convert the heat energy stored in the surrounding air into hot water (even at outdoor temperatures below minus 20 degrees C). Whilst early heat pumps were found to be noisy, modern, good quality units are often quieter than the flue of an oil boiler.

If you have an Air Source Heat Pump installed by Jowett and Jowett Renewables you may be eligible to receive the generous Government-funded Renewable Heat Incentive (RHI) grants.

The Advantages of a Heat Pump

  • More stable fuel cost
  • Fuel cannot be stolen as it is not stored on site
  • Fuel does not have to be ordered in bulk
  • Lower running costs
  • Lower carbon dioxide outputs
  • Greater reliability
  • How an Air Source Heat Pump works.
  • An air source heat pump, as the name suggests actually uses air as the source of the energy, whilst electrically driven, the purpose of the heat pump is to extract energy from outside air, condition it to useful temperatures, and deliver it to the heat distribution system using carefully matched controls.
  • Are heat pumps worth the investment?
  • Providing it’s designed and installed correctly a ground or air source heat pump can be an effective eco heating system that’s both cheap to run and that’s good for the environment.

Instead of burning fossil fuels to warm our homes, what if we could use naturally-occurring heat from the environment?

Introducing… air source and ground source heat pumps.

Read More button

What is a heat pump? How are they eco heating systems?

Heat from the sun is constantly warming our planet. An air, ground, or water heat pump is an electric eco heating system that absorbs this solar heat either from the air, earth or water. The heat pump then uses a small amount of electricity to compress this heat into a suitably high temperature – ready to be used for space heating and hot water. You can find out more about how a heat pump works here.

Are heat pumps worth the investment?

Providing it’s designed and installed correctly (speak to us to ensure you choose the best option for your property and a fully qualified installer to fit it), a ground or air source heat pump can be an effective eco heating system that’s both cheap to run and that’s good for the environment.

Modern heat pumps can last as long as 25 years, and if they’re MCS-approved, you could be eligible for receiving payment from the government via the Renewable Heat Incentive. This could see a large proportion of the initial cost returned to you over a period of 7 years.

What’s the difference between air & ground source heat pumps?

Put simply, air source heat pumps convert heat from the air to energy while ground source heat pumps use draw heat from the earth. Each has their own advantages so there’s no clear winner in terms of which is best. Water source heat pumps are less common, but work in a similar way (using a water source). You can find out more about air source heat pump systems vs ground source heat pumps here.

Do ground and air source heat pumps work in the UK?

You may be wondering if heat pumps can work effectively in the UK, taking our cold climate into account. In actual fact, all types of heat pump (water, ground, and air source heat pumps) can absorb heat even in very cold conditions (as low as -20°C). They’re already found in many domestic applications throughout Europe, and in much colder climates than our own. In Sweden alone, 97% of new builds come with a heat pump system, and over 20% of all households already have heat pumps installed as an eco heating system.

Eco heating systems

Heat pumps are considered one of the most efficient eco heating systems available today. This is because they don’t give off any carbon emissions locally, and they’re capable of transferring over 4 times more thermal energy than they use in electricity. In more practical terms, this high efficiency could equate to a 75% reduction in heating bills (when switching from an electric heater).

What’s more, if you switch to a green energy provider, your system could effectively be running carbon neutral.

Read less

Another box to click on the page

Heat pump Boiler comparison

So, the big rivalry – the heat pump vs boiler. This article compares the attributes of both home heating systems to find out which one will come out on top in a heat pump vs boiler standoff. Will it be the heat pump, the veritable new kid on the block? Or the long-reigning champion, the boiler?

Let’s find out.

Heat pump vs boiler round 1 – Efficiency

The efficiency of a home heating system is essentially how much of the energy supply is converted into useful heat energy. Historically, old boilers are considered 50 – 75% efficient, which means that a half to a quarter of the energy supplied to the boiler was wasted. Modern high-efficiency boilers (gas, LPG and oil) and biomass boilers have a much-improved efficiency of around and above 90%, with only small amounts of heat lost through the flue.

On the other hand, the efficiency of heat pumps can, in effect, reach as high as 350% (or in technical terms, a Coefficient of Performance of 3.5). This is because heat pumps work by absorbing the heat occurring naturally outside of your home and moving it indoors.

Heat pump vs boiler: 1 – 0

Heat pump vs boiler round 2 – Lifespan

A typical air source heat pump lasts for around 15 years, but allegedly newer models and ground source heat pumps have a lifespan of around 25 years. This longevity is put down to their robust design, and with only a few moving parts, there’s very little that can actually go wrong.

In comparison, a typical gas or LPG boiler’s lifespan is around 8 – 12 years.

Heat pump vs boiler: 2 – 0

Round 3 – Heat Pump & Boiler Space

The outdoor fan unit of an air source heat pump usually takes up as much space as a washing machine. This is usually (but not always) connected to an indoor heat exchanger (or hydrobox), which is roughly the same size as a regular boiler. Finally, the hydrobox connects to a hot water cylinder, just like a regular gas boiler.

A ground source heat pump requires roughly twice the floor area of your home (including all floors) to be split and dug into trenches, where long pipes are laid. This is obviously a large plot of land (and not a quick installation), but once these pipes are buried underground, it’ll be unnoticeable once the flora has regrown or concrete re-laid. The actual ground source heat pump unit sits inside your home, and can be anywhere between the size of a regular boiler down to that of a large shoebox.

On the other hand, some modern boilers (or ‘combi’ boilers) take away the need for a hot water cylinder altogether, heating water straight from the water mains. Generally speaking, these are only suitable in small houses or flats though.

So if you’re including the outdoor space required, the ground source heat pump is the biggest loser for this round. However, if you’re only comparing which heating system takes up the most room inside your home, the biomass boiler would probably be the biggest. These pellet-burning green heating systems are larger than standard gas boilers, although this will depend on the size of your house and the demand for heat.

Heat pump vs boiler: 2 – 0

Heat pump vs boiler round 4 – Upfront cost

If you’re looking for the quickest and cheapest option, you’re better off sticking with a gas boiler. The Energy Saving Trust (EST) estimates that a standard gas boiler replacement will set you back on average £2,300.

For homeowners not on gas mains, the cost of an air source or ground source heat pump by comparison is between £6000 – £8000 (air source, EST) or £10,000 – £18,000 (ground source, EST). However, you will be able to claim the vast majority of this back from the Renewable Heat Incentive (subject to performance). Similarly, you can receive a tax-free RHI income with a biomass boiler, which is predicted to cost £8,000 – £15,000 (EST).

Considering a heat pump’s longevity, it’s worth noting that you may also need to replace your boiler twice in the space of one heat pump’s lifetime.

Heat pump vs boiler: 2 – 1

Round 5 – Heating running costs

Despite the cost of electricity being roughly 4 times more than gas, oil and LPG*, the running costs are surprisingly similar (this is down to the heat pump’s high efficiency). What this means is, in the event of electricity coming down in price in the future, the running cost of heat pumps would be a fraction of conventional heating methods. Given the volatile nature of changing energy prices, we think this is likely to happen.

Of course, this is speculative – we can’t know for certain if and when these prices might change, but as more and more solar farms, wind farms and hydroelectricity plants appear across the UK, it stands to reason that the cost of electricity will fall.

Heat pump vs boiler: 2 – 2

Heat pump vs boiler round 6 – Maintenance

While annual maintenance checks are advised for heat pumps, they’re not necessary. They can help to preserve a high efficiency and prolong life expectancy, but you can get away with not having routine checks without serious consequences.

On the other hand, it’s strongly advised that boilers have at least annual maintenance checks from HVAC professionals. This is to ensure safety, namely to reduce the risk of carbon monoxide poisoning.

Heat pump vs boiler: 3 – 2

Round 7 – User experience

Since both gas boilers and heat pumps are fully automated, the user experience will largely depend on the model you choose. As with most modern appliances, there are umpteen extra functions to improve ease of use, comfort and control. App-controlled systems, timers and programmable room thermostats are just a few of the functions we think are worth looking out for.

Unfortunately, a biomass boiler will require slightly more effort, as you’ll have to manually fill it with wood pellets each time. There are options to have pellets delivered to your door, but this will depend on a willing third party located in your area.

Heat pump vs boiler: 3 – 2

Round 8 – Extra costs

While most boilers shouldn’t take more than a couple of days to replace, there are always extra costs that you hadn’t accounted for. The reality is that a heat pump has a few of its own requirements to meet so that it can work effectively. The building must be reasonably well insulated to achieve a low flow temperature, and you may have to increase the size of your radiators. If this is the case, we suggest installing underfloor heating.

Although costly, the large surface area of underfloor heating makes for a significantly lower flow temperature (thus smaller electricity bills), and it also means a room is much quicker to warm up than if you only had radiators.

Heat pump vs boiler: 3 – 3

Round 9 – Eco friendliness

Despite the efficiency of gas, oil and LPG boilers rising to approximately 90%, heat pumps don’t burn fossil fuels to generate heat, making them the clear winners of this round. Their high efficiency also means that even if the electricity powering the heat pump was generated in a coal-fired power station, the carbon emissions given off would be minimal.

Furthermore, there’s the option to power heat pumps on green electricity (from solar farms or wind farms), which would practically reduce their carbon emissions to zero.

Biomass boilers are also a green heating option worth considering. As they burn wood, they’re only emitting the same amount of carbon emissions that were absorbed, so they’re technically carbon-neutral.

Heat pump vs boiler: 4 – 3

Heat pump vs boiler highlights

So, after a gruelling 9 rounds pitting the heat pump against the boiler, do we have a out-and-out winner? Not really.

For homeowners who are off the gas mains grid, building a sustainable home, or simply trying to be a bit more environmentally friendly, we’d suggest investing in a heat pump. For those on gas mains, it’s probably better financially to replace your boiler with a high-efficiency one.

Do you agree with our heat pump vs boiler result? Leave a comment below. You can also find out more about heat pumps here on our website.

Want to find out how much your own heat pump will cost? Just fill out our contact form. One of our Technical Account Managers will soon be in touch for a quick chat about your project before providing you with a proposal.