Industrial heat pumps: process heat and high temperature

What counts as a process or high-temperature heat pump

A building-heating heat pump delivers water at flow temperatures suited to radiators, fan coils or hot-water cylinders. A high-temperature heat pump delivers heat at a higher temperature, aimed at processes such as washing, pasteurising, drying, cleaning and some heat used in manufacturing. A process heat pump is one built into an industrial heat system, often alongside other plant, and often a one-off design rather than a catalogue product.

The physics sets the limit. The higher the temperature a heat pump must deliver, and the larger the gap between its heat source and its output, the more work the compressor does and the lower the efficiency (COP). That is why process heat pumps are most attractive where the temperature lift is modest, for example upgrading waste heat at moderate temperature to a somewhat higher process temperature, and are harder to justify where the process needs very high temperature or direct steam. If you need heat above the range the heat pump can reach, the pump may only pre-heat, with other plant finishing the job.

High-temperature heat pumps above 100 °C

The International Energy Agency’s Heat Pump Technology Collaboration Programme (Annex 58) describes high-temperature heat pumps as emerging as a key technology for decarbonising industrial process heat, and its first task gives an overview of high-temperature heat pump technologies supplying temperatures above 100 °C. Models, refrigerants and achievable temperatures in this range are specialised and vary by manufacturer, so treat any supplier’s stated delivery temperature as something to verify against the process requirement. We have not verified which heat pump products can deliver steam or serve a given food-and-drink or drying process; ask for evidence on a comparable site.

Where the heat comes from

A heat pump moves heat; it does not make it. Its source decides both efficiency and feasibility. Typical sources for industrial sites include:

• Waste heat. Warm exhaust air, cooling-water loops, refrigeration condenser heat, compressed-air systems and process effluent. A steady source at a higher temperature than outdoor air gives a smaller temperature lift and a better efficiency than drawing from the air.
• Ambient air. Simple to access but coldest when heat demand is highest, as with any air-source heat pump.
• Ground or water. River, canal, mine-water or borehole sources at a stable temperature, subject to permissions and water-quality checks. See ground-source.

The match between source and demand in time also matters. If the waste heat is produced on a different schedule from when the process needs heat, thermal storage may be needed, which adds cost.

Refrigerants: R290 and R744 in general terms

Refrigerant choice shapes what a heat pump can do and how it must be installed and maintained. Two natural refrigerants are common in this market:

• R290 (propane). An efficient refrigerant with low global warming potential, but flammable (safety class A3), so plant rooms and outdoor siting need to follow the relevant safety standards, with limits on charge size and ventilation.
• R744 (carbon dioxide). Not flammable and low in global warming potential. It operates at high pressure and is well suited to producing high-temperature water, particularly where the source is cool and the output hot, though system design is specialised.

Synthetic refrigerants such as R32 are also used in building-scale units. UK F-Gas regulation applies to the handling of fluorinated refrigerants by suitably qualified people, and phase-down rules affect which fluids are available over time. This guide does not hold any such qualification; ask any supplier which refrigerant is proposed, why, and what the safety case is.

Cost and funding status

One published installer guide (Fuse Energy, updated 8 July 2026) gives high-temperature industrial heat pumps a planning band of £150,000 to £500,000 or more, covering the unit, controls, buffer vessels and the electrical and building-management integration. Process integration, heat-source works and storage can add to it, and the figure is a guide for scale only. See the cost guide.

On funding, the position is mostly closed:

• The Industrial Energy Transformation Fund (IETF) closed in July 2025. GOV.UK says it will not be extended, the planned second competition window of Phase 3 did not take place and no successor fund is planned.
• The Public Sector Decarbonisation Scheme was a public-sector scheme; its Phase 4 closed to new applications in November 2024 and no further phase has been announced.
• The Boiler Upgrade Scheme applies up to 45 kW thermal for a single heat pump (70 kW thermal for a multi-unit system, 300 kW thermal for a shared ground loop), which still excludes most industrial plant.

Capital allowances may apply but depend on classification; heating plant can be special-rate expenditure, and process plant may be classed differently. Ask your accountant. Check grants and funding and gov.uk for any new programme.

Who it suits, and who it does not

Process heat pumps tend to fit sites that have:

• Large, steady heat demand at a moderate process temperature.
• A usable source of waste heat or a stable water source close to the demand.
• Electricity at a price, or from on-site sources, that makes the energy-cost arithmetic work. At DESNZ Q1 2026 average medium-business prices of 25.0p per kWh electricity and 4.55p per kWh gas, a heat pump must reach a SCOP of about 4.8 to match an 88% efficient gas boiler on energy cost alone, and that is harder at high delivery temperatures.
• An electrical supply with headroom, or the means to reinforce it.

They fit poorly where the process needs very high temperature, where demand is short and intermittent, or where no heat source is within reach. A feasibility study by an independent engineer is a sensible first step for any industrial scheme. For smaller combined heating and hot-water duties on a building, a hybrid arrangement may be simpler.