The six main heat pump myths debunked

on | 6 min read
Heat pumps. and heat pump based solutions such as ambient loops or hot water heat pumps are proven technologies considered one of our main routes to achieving compliance with the new, 2022 Part L of the Building Regulations. The increased focus on heat pumps, including air source heat pumps, both monobloc and split system, has intensified the discussion on this low carbon technology that is sometimes misunderstood.
air source heat pump in a home

Here are the six common myths and misconceptions about heat pump technologies:

  • Heat pumps are expensive to run
  • The technology is costly to purchase
  • They are noisy and ugly
  • Heat pumps can only be installed in newly built homes
  • Specialist installers are required
  • Heat pumps can't supply mechanical cooling

Heat pumps are expensive to run

Heat pumps and hot water heat pumps provide an efficient way to meet the hot water and space heating demands within a building. Compared to boilers with a typical Coefficient of Performance (COP) of 0.9, heat pumps can achieve a COP of over 2.0 for hot water and over 3.0 for space heating. The higher efficiency of heat pumps increases their cost effectiveness.

The headline number quoted whenever a new edition of Part L appears is always a reduction in CO2 emissions required over the previous regulations. For Part L 2022, this figure is on average 31% lower than that in Part L 2013.

Achieving this target can be challenging. However, the specification of heat pumps will meet that challenge and can also help maximise efficiency and minimise running costs. Analysis by the Regulatory Assistance Project (RAP) shows that with a well fitted heat pump, a saving of up to 27% for heating bills can be enjoyed per household compared to using a gas boiler.


Project 80 – hot water heat pump solutions are used to achieve 80% CO2 emissions reduction

project 80 housing construction site

Project 80 was designed to provide affordable homes by social housing provider Midland Heart. This project aims to not just meet the new Part L, F, and O regulations, but to comply with the expected 80% CO2 emissions reduction requirement of the 2025 Future Homes Standard. A fully electric hot water heat pump system by Dimplex was chosen for Plots 3 and 4. Edel hot water heat pump and direct acting panel heaters proved to be a cost-effective way to meet regulations and give residents control over their internal environment and their energy bills.

Heat pumps are expensive to buy

Heat pumps are reducing in cost as the market grows. The initial outlay can be offset by the government's Boiler Upgrade Scheme, launched in April 2022. This gives homeowners a grant of £5,000 towards the installation of an air source heat pump and £6,000 towards the cost of a ground source heat pump installed by an MCS (Microgeneration Certification Scheme) accredited installer. This scheme is expected to run for three years, leading to 2025. As with all government schemes, it is worth checking that it is still available and keeping an eye out for new schemes as the push to net zero carbon gathers pace.



Flitch End – overcoming local planning restriction with hot water heat pump technology

new build flats

The Dimora Homes 48 residential apartment project overcame the challenge of local planning restrictions by specifying Hot water heat pump solution by Dimplex. The system with the Edel hot water heat pump at heart and direct acting panel heaters, met the required renewables contribution and saved the cost of roof reinforcement and 50 PV panels. It also meant one less service connection was required on site saving resources and space. The replacement of a wet system with pipes, radiators and boilers reduces the number of annual maintenance call outs and generates savings in reduced service visits.

Heat pumps are noisy and ugly

Ground source heat pumps and water source heat pumps are not regarded as noisy technologies. The sound level air source heat pumps (ASHPs) produce will depend on the type, monobloc or split system, make and model of the unit. This must be no greater than 42 dB(A) under the Microgeneration Certification Scheme Planning Standards (MCS) before they can be allowed as permitted development.

To put this into context, 42 dB(A) is like the noise level you would experience in a quiet library. Some exterior ASHPs can have special noise reducing casings if they are installed in enclosed spaces where noise might be more noticeable, such as courtyards. Ducted ASHPs can be installed inside the dwelling as another way of achieving the required level of acoustic comfort.

As for appearance, some types of heat pumps can be installed internally. Hot water heat pumps, such as the Edel hot water heat pump, are integrated within a hot water cylinder that fits inside a standard service cupboard. The Edel hot water heat pump uses a low noise fan to draw in outside air, a sound resistant hood and anti-vibrational pads to ensure its quiet operation.

Avenue Road – designing out gas with heat pump technology

Dimplex avenue road project apartments

The Avenue Road project saw the construction of 14 build to rent apartments where the internally installed Edel hot water heat pump and slimline PLXE direct acting panel heaters from Dimplex provided an attractive and simple solution to design out traditional gas boilers. The specification was completed with Natural Air180 mechanical ventilation with heat recovery, intermittent mechanical ventilation and electric towel rails to deliver convenient and practical hot water and space heating needs of the residents. The compatible specification expedited the installation.

Heat pumps can only be installed in newly constructed homes

As we discussed earlier, changes to Part L, along with the switch to electricity as the primary fuel source, mean that heat pumps are becoming the 'go-to' solution for new build homes. However, they can also be installed in existing homes that undergo a deep retrofit. Where the fabric energy efficiency is high, low carbon heating technologies are a viable alternative to gas and can deliver hot water and space heating effectively.

Highly efficient hot water heat pumps provide the highest energy demand service. With hot water delivered efficiently by the heat pump hot, direct acting panel heater to provide space heating demands. Mechanical ventilation systems can be specified as a complimentary to ensure the retrofit dwelling maintains good indoor air quality.

Harbour Lofts – communal ambient loop for Poole’s boutique regeneration project

Zeroth Ambient Loop system inside apartment cupboard

Harbour Lofts, a regeneration project in Poole’s Quayside aimed to create nine boutique apartments. The challenge of this project involved incorporating heating systems into the limited internal sp.  ace available in the building. In apartment, heat pumps that form part of The Zeroth Energy System by Dimplex are fitted into the prefabricated utility cupboards leaving enough space for a washing machine or dryer. Specification of the ambient loop with an air source heat pump as a central plant eliminated the need for externally installed service, helping simplify local planning compliance

Heat pumps require specialist installers

Heat pump installers, like gas boiler installers, are trained to fit the equipment correctly in line with the manufacturer's guidelines, applicable industry standards, and regulations. So, heat pumps do not require specialist installers.

It is widely acknowledged that more installers of heat pumps and other low carbon technologies will need to be trained to meet the growing demands created by switching from fossil fuel powered systems. They are likely to come from the 100,000 or more existing gas installers who will retrain as demand for the installation of low carbon technologies increases.

Manufacturers of innovative low carbon technologies, such as ambient heat networks and hot water heat pumps, often design their systems to be pre-plumbed and pre-wired to optimise the speed and quality of installation. For example, both the Edel hot water heat pump and The Zeroth in the apartment unit are integrated within water cylinders in the factory and arrive on site where they can be installed by a certified plumber or electrician.

Heat pumps can't supply mechanical cooling

How a heat pump works is often quoted as being 'like a refrigerator in reverse'. Therefore, it is not difficult to see that reversing the air source heat pump operation would provide low carbon comfort cooling in the summer.

As the effects of climate change increasingly impact our lives and overheating becomes a greater issue, switching to low carbon cooling technologies will address housing’s increased cooling demand in a way that fossil fuel heating systems are incapable of delivering.


If you would like more information about any of the heat pump 'myths' we have covered in this blog or how Dimplex heat pumps and range of low carbon HVAC solutions could help with your project, please contact one of our HVAC specialists.