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How do commercial heat pumps work? The simple UK guide to lower bills & carbon (2025)

How do commercial heat pumps work? (UK guide for commercial building owners)

Commercial heat pumps move heat from the air, ground, water, or waste-heat into your building using a refrigeration cycle (evaporator → compressor → condenser → expansion valve). They don’t burn fuel; they concentrate low‑grade heat and deliver usable hot water for space heating and DHW—often at 2–4+ units of heat for every 1 unit of electricity (COP). This makes them a strong route to electrify heating in offices, schools, warehouses, hotels, and healthcare sites.

  • Best efficiency at lower flow temperatures (think 45–55 °C where possible).
  • Choose the right source: air (fast install), ground (stable, efficient), water (high performance), or waste‑heat (top value if available).
  • Integrate with BMS, thermal storage and smart tariffs to shave running costs.
  • A good design can beat gas on cost per kWh of heat, depending on your COP and tariffs.

Last updated: 8 September 2025

Table of contents

What is a commercial heat pump?

A commercial heat pump is a low‑carbon heating system that uses electricity to move heat from a source (outdoor air, the ground, a water body, or waste‑heat) into your building. It can heat radiators, fan coils, AHUs, underfloor circuits and make domestic hot water (DHW). Many units are reversible, so they can cool in summer and heat in winter.

How do commercial heat pumps work step-by-step?

Think of it like a fridge run in reverse:

  1. Evaporator – The refrigerant absorbs low‑grade heat from air/ground/water and boils.
  2. Compressor – An electric motor compresses the vapour, raising the temperature.
  3. Condenser – The hot refrigerant rejects heat into your water or air loop (this is the useful heat).
  4. Expansion valve – Pressure drops; the refrigerant cools and returns to the evaporator.
  5. Control system – The BMS optimises flow temperatures, staging and defrost cycles for best COP/SCOP.

Because the system moves heat rather than making it, you can see COP 2–4+ depending on source and flow temperature.

Benefits of commercial heat pumps (10 quick wins)

  1. Lower energy use per kWh of heat vs direct electric or older systems.
  2. Lower carbon today (with the greener UK grid) and future‑proofed for tomorrow.
  3. Heating & cooling from one system (reversible) for year‑round comfort.
  4. Stable running costs with smart controls, weather compensation and thermal storage.
  5. Works with hydronic emitters (fan coils, UFH, LTHW) at efficient low flow temps.
  6. Scalable arrays (cascade/N+1) for redundancy in larger buildings.
  7. Lower on‑site emissions (no flues, fewer combustion safety risks).
  8. Great for refurb when paired with fabric upgrades and emitter right‑sizing.
  9. Supports ESG goals and helps with EPC/MEES pressures in commercial property.
  10. Advanced controls (BMS integration, demand response, off‑peak optimisation) for better SCOP.

What are the main types (air, ground, water, high-temp)?

Use this at‑a‑glance guide to pick the right source for your site.

Heat source type Typical flow temps (°C) Indicative COP range* Where it shines Watch‑outs
Air‑source (ASHP) 40–60 (some to 70) 2.0–3.5 Quick to deploy, rooftops/plant yards, retrofits COP varies in cold weather; plan defrost and acoustics
Ground‑source (GSHP) 45–65 2.8–4.2 High efficiency, stable all year, boreholes/loops Higher capex; needs ground space or drilling
Water‑source (WSHP) 45–65 3.0–4.5 Rivers, lakes, aquifers, ambient loops; campuses Permits, filtration, environmental constraints
High‑temperature / Waste‑heat 60–90+ 2.0–3.0 Legacy emitters, DHW, process loads, data‑centre heat Efficiency drops at higher temps; source availability

*Real COP depends on design, source temperature, and your required flow temperature. Good system design is key.

How to integrate with existing heating, DHW and BMS

  • Emitters: For best efficiency, design for low‑temperature emitters (larger radiators, fan coils, UFH, AHUs).
  • Hydraulics: Use buffer/thermal stores for stable operation and DHW recovery.
  • Controls: Connect to BMS for weather compensation, setpoint resets, staging and load shifting.
  • Legionella strategy: For DHW, allow pasteurisation cycles or a dedicated high‑temp stage where needed.
  • Chilled water: Reversible units can feed CHW loops for cooling; WSHP/loops can offer simultaneous heat & cool.

How to choose: air vs ground vs water (decision guide)

  • Limited space, fast deployment? Start with ASHP on roof or yard.
  • Land or drilling access? GSHP offers strong, stable efficiency.
  • Near a water body or network? Consider WSHP or ambient loop.
  • Old high‑temp radiators/DHW at 70–80 °C? Look at high‑temp or hybrid strategies while you plan emitter upgrades.
  • Noise or planning sensitivity? GSHP/WSHP are often quieter on site.
  • Grid capacity tight? Add thermal storage and smart controls to shave peaks.

How to work out running costs vs a gas boiler

A simple way to compare:

Cost per kWh of heat (heat pump) = Electricity unit price ÷ COP
Example: If electricity is £0.22/kWh and your seasonal COP is 3.0, your cost per kWh of delivered heat ≈ £0.073.

Cost per kWh of heat (gas boiler) = Gas price ÷ Boiler efficiency
Example: If gas is £0.08/kWh and a 90% efficient boiler, cost per kWh of heat ≈ £0.089.

Your numbers will vary—flow temperature, controls, and source make a big difference. We can model this for your building and tariff mix.

Top Tips for design, installation and maintenance

  1. Start with the fabric. Lower heat loss = lower flow temps = higher COP.
  2. Size for reality. Use measured loads where possible; consider cascade arrays and N+1.
  3. Design for 45–55 °C flow where the building allows; only push higher when needed.
  4. Right emitters. Upsize or switch to fan coils/UFH for low‑temp comfort.
  5. Balance & hydraulics. Add a buffer and correct hydraulic separation to stop short‑cycling.
  6. Smart controls. Weather compensation, night set‑back, and demand response improve SCOP.
  7. Plan defrost. For ASHP, design air paths and drainage; protect winter COP.
  8. Water quality. Treat closed loops; follow good water chemistry to protect plates and pumps.
  9. Commissioning matters. Log setpoints, curves, and SCOP; hand over with training.
  10. Annual servicing. Clean coils/filters, check refrigerant, test safety and update BMS strategies.

FAQs

What is COP vs SCOP?
COP is instant efficiency (heat out / electric in). SCOP is the seasonal version across a year’s weather.

Can heat pumps work below 0 °C?
Yes. COP drops in very cold weather, but good design and defrost control keep performance strong.

Do I need new radiators?
Not always. If you can run at lower flow temps, existing emitters may be fine; some will need up‑sizing.

Can a heat pump make hot water?
Yes. Many systems produce DHW. For higher temperatures, use high‑temp units, a booster stage, or pasteurisation cycles.

How long do they last?
Commonly 15–20 years with proper maintenance.

Is a hybrid (boiler + heat pump) worth it?
For some sites, yes – especially where peaks or legacy high temps exist. It can be a step‑by‑step path to full electrification.

  • High‑temperature units (70–90 °C+) are maturing, helping legacy radiator systems and DHW without major emitter swaps.
  • R290 (propane) and low‑GWP refrigerants are seeing wider use for better efficiency and sustainability.
  • Waste‑heat recovery from data centres, supermarkets, and industry is growing—turning “throw‑away” heat into building heating.
  • Thermal storage + smart tariffs let sites charge heat when power is cheap/green and discharge at peak times.
  • Networked ambient loops (5th‑gen district energy) enable buildings to share heat and cool across a campus or town centre.
  • Demand‑side response (DSR) opens new revenue by flexing heat load to support the grid.

Mini case story

City centre office, 6,500 m²
The client had two old gas boilers and rising energy costs. After a heat‑loss check and emitter survey, we installed a roof‑mounted ASHP array with buffer storage and BMS weather compensation. Flow temperature was set to 50–55 °C for most of the season. Result: stable comfort, strong seasonal COP, and a clear cut in gas use. The team now monitors SCOP and setpoints monthly for continuous improvement.

Conclusion

Commercial heat pumps offer a clear, practical route to electrify heating in commercial buildings. They move heat rather than burn fuel, deliver heating, cooling and DHW from one system, and perform best at lower flow temperatures with smart controls and thermal storage. With the right source (air, ground, water or waste‑heat) and a solid design, many sites achieve seasonal COPs of 2–4+, cut carbon, and stabilise running costs.

If you’re unsure which option fits your building, book a quick feasibility chat. We’ll review your loads, tariffs, emitters and plant space, then map a phased plan—often starting with a hybrid step and moving to full electrification when it makes sense.

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