Air-Source Heat Pumps (Commercial): Heat pumps for businesses

Why air-source heat pumps are the default first move for most businesses

For the great majority of UK businesses looking to decarbonise heating, an air-source heat pump is the most practical place to start. There are no boreholes, no drilling rigs and no ground works, so the route from a gas or oil boiler to low-carbon heat is the fastest and least disruptive of any option we offer. The units sit in an external louvred compound or on a roof plant deck, draw heat from the outside air, and deliver three to four units of heat for every unit of electricity. For a business that runs on a budget and a timetable, that speed and simplicity matter as much as the technology itself, which is why air-source is the system most of our commercial enquiries end up specifying.

The case is strongest where an ageing gas boiler is nearing the end of its life and the organisation has a net-zero commitment with no obvious funding route. This is precisely the position so many businesses find themselves in, because the headline £7,500 Boiler Upgrade Scheme is domestic-only and does nothing for a commercial building. Air-source heat pumps for businesses are the workhorse answer: they scale from a single small office up to a large mixed-use site through cascaded modular units, they pair well with the lower flow temperatures that lift efficiency, and they keep on-site combustion off the balance sheet for Scope 1 reporting. Get the design right and you replace an unpredictable gas bill with a heating system you can plan around for twenty years.

It helps to be clear about why this matters now. Heat accounts for roughly a third of UK carbon emissions, and for most commercial buildings the gas boiler is the single largest source. An air-source heat pump moves heat rather than burning fuel, delivering an SCOP, the seasonal coefficient of performance measured to BS EN 14825, typically between 3.0 and 4.0, which means three to four units of heat for every unit of electricity. Against a volatile gas market and the Climate Change Levy that loads extra cost onto fossil fuel, that efficiency is what turns a heating system into a budgeting tool. For a facilities, estates or energy manager juggling ageing plant, MEES and EPC pressure, and a board-level net-zero pledge with no funding attached, the air-source route is usually the one that delivers the most decarbonisation for the least disruption in the shortest time.

What a typical install looks like and how we size it

For a commercial air-source project we usually design in the 40 to 500 kW thermal range, built from a single unit up to cascaded banks of 4 to 12 modules, occupying a plant area of roughly 20 to 200 square metres as an external louvred compound or roof plant deck. A system that size delivers in the region of 80,000 to 1,000,000 kWh of heat a year and removes somewhere between 15 and 180 tonnes of CO2 annually. We never size from floor area alone. Sizing is driven by your building's peak heat-loss and its annual heat-demand profile, so we run a proper heat-loss survey and review at least twelve months of gas or oil consumption before we commit to a number. The cardinal rule is to keep the flow temperature low, because every degree of reduced flow temperature lifts the seasonal efficiency, so we design for 45 to 55C wherever the emitters allow it, with selective emitter upgrades rather than a full strip-out where they do not. We specify to BS EN 14825 for SCOP and BS EN 14511 for rated COP so the performance we quote is directly comparable to any other compliant supplier.

Costs, payback and tax relief

A commercial air-source project typically lands between £60,000 and £600,000 depending on the building's peak load, the emitter upgrades required and any electrical supply work, with a simple payback in the region of 8 years and lower-carbon, more predictable heating for the long service life after that. The single biggest financial lever for a business is capital tax relief. Heat pumps qualify as plant and machinery, so a company paying corporation tax can claim full expensing, a 100% first-year deduction with no upper cap that is permanent from April 2026, worth up to 25p of tax saved for every pound spent at the 25% rate. Sole traders and partnerships use the Annual Investment Allowance instead, up to £1m of qualifying spend at 100%. Where the system exports nothing this relief works on the whole installed cost, and our cost guide sets out worked numbers, while the funding page covers the grant routes in full. Always confirm the exact tax treatment with your accountant, as wiring and ancillary works can fall outside full expensing but usually still qualify for AIA.

Funding routes in detail

Because the Boiler Upgrade Scheme does not apply to commercial premises, the funding playbook for a business is different and, frequently, larger. Public-sector bodies, NHS trusts, schools, colleges, universities, local authorities and emergency services should look first at the Public Sector Decarbonisation Scheme administered by Salix for DESNZ, which funds low-carbon heating and demand-reduction measures and meets the cost over and above a like-for-like fossil-fuel replacement, through competitive application windows. Any company paying corporation tax can use full expensing on the capital, and unincorporated businesses use the Annual Investment Allowance. Where an air-source scheme forms part of a wider multi-building or campus project, the Green Heat Network Fund can contribute up to 50% of eligible costs. We map which of these routes you qualify for and build the application around the project rather than treating funding as an afterthought.

Compliance and sector considerations

For systems up to 45 kWth, MCS certification, or a recognised commercial equivalent, is required to access most grant routes, and our engineers work to the MCS 025 installer competency standard. Above 45 kWth we design to CIBSE and BSRIA standards using BS EN 14511 and BS EN 14825 performance ratings. Many commercial air-source installs fall under permitted development, but they are subject to size, siting and noise limits, so a BS 4142 acoustic assessment is commonly required to demonstrate the external unit will not disturb neighbours, and we treat that as standard rather than an extra. Listed buildings and conservation areas need consent. All refrigerant handling is carried out by F-Gas certified engineers under the UK F-Gas Regulation, and we design around the refrigerant phase-down, specifying lower-GWP options such as R32 (A2L) where appropriate. Large heat pumps add meaningful electrical load, so we confirm available supply capacity early, because a DNO supply upgrade can be the longest-lead item in the whole project.

How we approach this kind of project

Our approach is built to remove the two things that have burned commercial buyers before: vague numbers and over-optimistic quotes. We model running cost and carbon from your own half-hourly meter data and at least twelve months of consumption, at current and forecast prices, and we share the full model so you can stress-test it or get a second opinion. We size for self-consumption and a low flow temperature, survey your emitters and pipework first so you do not pay for a strip-out you do not need, and check the plant compound, siting and acoustics before we quote rather than on the day. Where a DNO supply upgrade is needed we submit the G99 grid application early to start the clock. You receive a fixed-price proposal and an insurance-backed warranty, and the performance figures are quoted to BS EN 14825 so they stand up against any compliant rival.

The running-cost question deserves a straight answer, because it is the one most businesses ask first. Electricity currently costs roughly three to four times the unit price of gas, so a heat pump only wins on running cost if the SCOP and the tariff are right. A unit delivering an SCOP of 3.5 produces 3.5 units of heat per unit of electricity, which offsets most of that unit-price gap, and the biggest lever on SCOP is flow temperature, which is exactly why we design for 45 to 55C wherever the emitters allow. With a sensible electricity tariff and a low flow temperature, well-designed commercial air-source systems are at or below gas running cost today, and the gap improves further as gas carbon levies rise and the electricity grid continues to decarbonise. We never quote a running-cost figure from an estimate; it comes from your actual consumption, so you can see the maths rather than take it on trust. We would rather lose a job to honest numbers than win it on a figure we cannot stand behind.

Disruption is the other recurring worry, and air-source is the gentlest option here. Because the new plant is largely pre-assembled, an air-source retrofit is typically four to twelve weeks on site once the design and any DNO supply work are agreed, and the live boiler cutover is usually a matter of hours rather than days. We plan the changeover around your operating calendar, normally spring or autumn rather than a peak-heat week, and for phased designs the existing boiler can be kept running as backup through commissioning, so you are never without heat. With routine annual or six-monthly servicing covering the refrigerant circuit, electrical checks, controls and a performance review against design, plus remote monitoring to flag any underperformance early, a commercial air-source heat pump has a service life of around 15 to 20 years.

An illustrative example

As an illustrative composite based on a typical commercial air-source project, a 70-bed care home running a pair of ageing gas boilers nearing failure, with a year-round heating and hot-water demand and rising bills, installed a 180 kW cascaded air-source system of six modular units with selective emitter upgrades and the existing boiler retained for peak backup. It delivered around 360,000 kWh of heat a year at an SCOP near 3.6, cut on-site combustion by roughly 85% and saved in the region of 55 tonnes of CO2 a year, with a payback close to 7.5 years. The work was scheduled in autumn around the operating calendar with the old boilers kept live through commissioning, and full expensing delivered first-year tax relief. The figures are illustrative and depend on your building, emitters, tariff and consumption.

If your building runs year-round or you want to compare the long-term economics, see commercial ground-source heat pumps, or for a lower-capital stepping stone read about a hybrid boiler-replacement retrofit. When you are ready, request a feasibility study from your consumption data, work through the cost guide and funding routes, or read the heat pump FAQs first.