Commercial heat pumps in detail Your guide to specifying and installing commercial air source heat pumps

What space is available for housing ASHPs?

When installing external heat pumps, it’s important to consider space requirements, clearances, and local planning regulations, as well as factors like weight, particularly for rooftop installations. The position should ensure sufficient airflow to prevent short-circuiting or freezing, maintaining efficiency. Additionally, the distance from existing heating plant connections and distribution pipework affects heat loss, requiring better insulation for longer distances. Extra clearance may be needed for multiple units and/or buffer tank.

What are the site noise requirements?

To minimise noise from heat pumps, it’s important to follow local noise regulations and consider installation locations, avoiding areas near windows, gardens, or living spaces. Heat pumps can be equipped with quiet modes, programmable schedules, and advanced controls that adjust fan and compressor speeds to reduce noise, especially during off-peak hours. Noise can be further minimised with acoustic surrounds, silencers, anti-vibration feet, and flexible hoses.

Further reading:

• Why do you need a buffer tank when installing a commercial air source heat pump?

In a new build:

• The UK government has ruled that gas boilers will be banned in all new homes built after 2025, as part of the Future Homes Standard, designed to tackle climate change, it requires new builds to have low carbon systems like heat pumps and aims to reduce carbon emissions by 75-80% compared to current standards. Starting in 2021, all new build homes are expected to achieve a 31% reduction in carbon emissions. From 2025, it will be mandatory to fit low carbon heating systems in new buildings, making homes more energy-efficient with solutions such as insulation and heat pumps. This ruling is part of the government’s ten-point initiative to help the UK reach its target of net zero carbon emissions by 2050.

In plant room replacements there may be more reasons to install a commercial air source heat pump:

• To qualify for the government schemes that require low carbon technology

Schemes such as the public sector decarbonisation scheme require your client’s project to install low carbon heat systems such as air source heat pumps in order to achieve the sustainability requirements and be awarded funding. Air source heat pumps are an effective low carbon heating solution for large projects.

• To meet business carbon targets

Using heat transfer principles, air source heat pumps are carbon neutral which means they do not produce any greenhouse gas emissions. For businesses looking to improve their carbon footprint or meet ambitious carbon targets, heat pumps can help them by reducing the carbon emissions generated from their heating and hot water.

• To be as green as possible and/or reduce reliance on gas-powered technologies

If you’re concerned about your operation’s carbon footprint and want to adopt low or zero carbon heating, installing a heat pump could meet your sustainability goals.

• To save money

When simply comparing the unit cost, electricity is currently 3-4 times more than the cost of gas, however this doesn’t factor in the costs of installation, maintenance, lifespan and most importantly, energy efficiency which in turn influences running costs. Heat pumps generally have lower running costs than gas boilers because of their higher energy efficiency. As heat pumps are effectively extracting ‘free energy’ this can create very high efficiencies as the energy extracted is greater than the energy used to drive the heat pump. This means the running cost of the heat pump is considerably less than a gas boiler. So whilst the initial setup costs of a heat pump might be more significant than that of a gas boiler, in the long-term, heat pumps could provide a more efficient and cost-effective heating solution.

• To change from oil or LPG to electric

If you’re replacing an oil or LPG system and aiming to cut running costs, a heat pump delivers more heat per unit of electricity than conventional oil/LPG boilers.

• To future-proof a building

With the UK targeting net zero emissions by 2050 and tighter energy-efficiency regulations imminent, a heat pump ensures long-term compliance and resilience to evolving energy requirements.

Further reading:

• What are the options when a heat pump might not suit retrofit specification?

• Customer case study - a cascade of Tyneham 290HT commercial heat pumps at Cambridge primary school

• What radiators are currently available?

Heat pumps run more efficiently at lower flow temperatures so need more radiator surface area. Existing radiators may need upsizing or replacement.

• Does the property have other systems in place to increase its efficiency e.g. LED lighting, insulation, double glazing, etc.?

Installing an ASHP should not be the only consideration when trying to decarbonise the property. The fabrication considerably impacts its efficiency and can influence the effectiveness of the overall heating system, for example, is the insulation of the building adequate?

• Have you completed an inventory of the existing devices?

Before selecting the type of heat pump that will be installed in the property, an inventory of existing devices should be performed. This inventory will include the number of radiators and the number of appliances running on the same fuse as the heat pump. It is important to take these devices into consideration as they will influence the input into the property and the supply demand.

• What is the fuse size of the property?

The fuse size should also be considered – if the fuse voltage is not high enough to accommodate installing a heat pump alongside all of the other devices running on the same fuse, then either the heat pump or the fuse size of the property will have to be reconsidered.

• Have you completed a load survey and calculated the maximum demand of the property?

A load survey determines the highest current your property could draw if every circuit ran at once. You should carry this out before choosing your heat pump size. If the survey shows demand above your consumer unit’s capacity, you’ll need to apply to the Distribution Network Operator (DNO) for a supply upgrade or look at reducing your electrical loads. With those figures in hand, you (or your installer) can finalise the design, arrange any necessary supply work and install the heat pump so that your electrical system meets safety and performance requirements.

• What is the incoming electrical supply and spare capacity of the property?

When planning to install an ASHP or any significant electrical appliance, it’s crucial to ensure that the existing electrical supply can handle the additional load. Spare capacity is the amount of additional electrical load that the current electrical system can support without requiring upgrades. It is important to know whether the building’s electrical system has enough spare capacity to accommodate the ASHP. What are the actual operating temperatures of the current system? We are often told its 80/60 or 82/71 but if you can check the radiator temperature if surveyed in the heating season, they are often much lower than you think.

• Understanding operational costs

Compare existing operating costs (e.g. for gas or oil heating) with the projected running costs of a heat pump to work out potential savings of switching to a heat pump. Ensuring you have accurately calculated the heat demand of the building is therefore essential for reliably working out the potential cost savings.

Further reading:

• Customer case study: a hyrbid heat pump system for Stansfield Business Park

What type of refrigerant does the commercial ASHP use?

Heat pumps are based on tried and tested technology, but the refrigerant used in many older models (and even some still being marketed today) have a high Global Warming Potential (GWP). Refrigerants with a high GWP contain extremely potent greenhouse gases, that warm the planet. The use of natural refrigerants such as R290 (Propane) and R744 (CO2) are becoming increasingly popular because they have low GWP and ODP when compared to manufactured refrigerants such as R407c, R410a and even R32. Natural refrigerants also have much higher heat transfer efficiency and are cheaper to replace and maintain than other refrigerants.

This is why Hamworthy Heating offer a range of commercial air source heat pumps:

• Tyneham 290HT - available in outputs of 15-65kW

• Tyneham CO2 & CO2Q - available in outputs of 65-130kW

• Tyneham - available in outputs of 14-70kW

Will you need to maintain services or need high turndown?

Turndown ratio refers to the ability of a heating system to operate efficiently at lower capacities. A high turndown ratio allows a system to reduce its output significantly without shutting down completely. This capability is important for maintaining energy efficiency and comfort when the full capacity of the system is not needed. All Tyenham heat pumps turn down to 50% of the rated output.

Will you need multiple units?

Heat pump cascade systems combine several units to meet varying heat demands. They work together during peak demand and operate individually at lower loads, improving efficiency by reducing unnecessary energy use.

Could you consider a hybrid system to meet peak loads in the winter?

In some buildings, the cost of installing and running a heat pump may be higher than a high-efficiency gas boiler due to the higher electricity costs or insufficient thermal energy for the heat pump. Additionally, buildings with high heat demand or limited funding for grid connection may not be suitable for standalone heat pumps. In these cases, a hybrid or bivalent system combining heat pumps with gas boilers can help, especially during cold weather.

Further reading:

• Why the right refrigerant is important when selecting a heat pump

• Why might you consider a cascade for your next heat pump project?

• What are the options when a heat pump might not suit retrofit specifications?

• Customer case study: Grantham health centre install hybrid heating system

In a single-phase supply:

There are two conductors, one live wire and one neutral wire. Single-phase power is commonly used in residential settings and for smaller commercial applications. Single-phase power is relatively simple and easy to install, making it suitable for domestic use. Single-phase ASHPs can be powered by a standard 230 volt outlet.

In a three-phase supply:

There are four conductors, three live (hot) wires and one neutral wire. These three live wires are typically referred to as phase wires. Three-phase power is commonly used in industrial and commercial settings, where higher power demands are required. It’s used to power heavy-duty appliances. Three-phase power is more efficient for transmitting large amounts of electrical power over long distances and is preferred in commercial or industrial applications due to its ability to provide a constant and balanced power supply. The phase supply of the building needs to be three-phase for ASHPs that require more than 230 volts. If you are considering installing an ASHP it is important to get the property assessed so the right ASHP can be recommended and to identify if you have the correct power supply. If your ASHP recommendation requires a three-phase power supply, it is necessary to check with the local utility company to see if it is available.

Funding for low-carbon heat solutions in commercial buildings can be limited, but where it exists, it makes installing heat pumps more feasible. Government-backed grants, such as the Public Sector Decarbonisation Scheme (PSDS), enable you to consider heat pumps for your projects. Other public sector schemes include the Green Heat Network Fund and the Social Housing Decarbonisation Fund.

Have you contacted the Distribution Network Operator (DNO)?

As the deployment of low carbon technologies increases, it is important that network operators are aware of the number and location of energy assets within their network. DNO notification allows operators to record installation numbers of low carbon technologies, which is critical for maintaining safe and efficient operation of the electricity network. Each time a heat pump is installed on a premises, the relevant DNO must be informed. All Tyneham R290 Heat Pumps are registered on the ENA, (Energy Networks Association).

What is the supply capacity of the project?

In order to install an ASHP, the property must have a large enough supply capacity to accommodate it. Authorised Supply Capacity (ASC) is the amount of agreed electricity from the grid that is reserved for your use at any time. It is measured in kVA.

Are there any load-limiting devices at the property?

Load limiting devices limit the demand (i.e., the amount of current drawn) by a premises. It is the responsibility of the installer to ensure that the maximum demand(s) stated are correct, factoring in the effects of any load limiting devices. Load limiting devices must also have a ‘fail safe’ i.e., when not operating, or due to failure, it must not result in the limitations of the connection being exceeded. This is important when calculating the maximum demand.

Further reading:

• Considerations for commercial air source heat pump selection, specification and design

Hamworthy heat pumps for commercial buildings

We have led the way in commercial heating by ensuring our heating products are at the forefront of technology, quality and design by delivering both high efficiency and low running costs. In 2022 we launched our first commercial air source heat pump and we have have taken the next step forward by introducing our Tyneham natural refrigerant commercial air source heat pumps.

You can explore our range of low carbon, commercial air source heat pumps here:

• Tyneham 290HT

• Tyneham

• Tyneham CO2 & CO2Q