Thermodynamic heat pump installation for commercial buildings: CO2 reduction and the tertiary decree
Tertiary scheme: consumption reduction trajectory to be met at the 40, 50 and 60% milestones.
52% average reduction in final heating consumption: this is the gain measured by Kytom across 60 commercial sites fitted with thermodynamic heat pumps between 2018 and 2024. The air-source or ground-source heat pump replaces gas or oil boilers with a field SCOP of 3.8 to 4.2 in the H2 zone, compliant with the NF EN 14825 standard. Each operation runs over 12 weeks, from the thermal audit to BMS commissioning, on average floor areas of 850 m². The emission factor drops from 227 to 79 gCO2 per kWh NCV. The trajectory covers the 2030, 2040 and 2050 regulatory milestones, with 18 to 25% of funding through the BAT-TH-157 Energy Savings Certificates.
The Eco Energie Tertiaire scheme requires buildings over 1,000 m² to reduce final consumption by 40% in 2030, 50% in 2040 and 60% in 2050, relative to a reference year after 2010. Annual reporting has been mandatory since 2022 for tracking heating and cooling consumption.
Heating accounts on average for 47% of an office building’s consumption, which makes the heat pump a priority lever in technical decision-making. Reference ratios structure the decision:
- condensing gas boiler: 95% useful efficiency on GCV;
- modulating air-to-water heat pump in the H2 zone: SCOP 3.8 to 4.2;
- water-to-water heat pump on vertical geothermal probes: SCOP above 4.5 thanks to a stable source at 12 °C;
- French commercial building stock: 990 million m², of which 11% fitted with thermodynamic systems at the end of 2023.
Declared performance is governed by the European standards in force; CE marking and Eurovent certification lock in the catalogue values.
Kytom’s 5-step method scheduled over a 12-week worksite
Kytom structures each heat pump operation according to a sequence proven across 60 commercial sites since 2018 5311 and reference.
- Energy audit: consumption readings over 3 rolling years, dynamic thermal modelling, identification of the declared reference year.
- Sizing: calculation of heat losses using the applicable standard method, simulation of cooling loads, choice between air-to-water, water-to-water geothermal or VRF heat pumps. Oversizing remains capped at 110% of peak power to preserve the SCOP.
- Integration engineering: verification of roof load-bearing capacity (250 to 450 kg per outdoor module), acoustic treatment to comply with the neighbourhood noise order (5 dB(A) daytime emergence, 3 dB(A) at night), reservation of R32 or R454B fluid runs in accordance with the F-Gas regulation revised in 2024.
- Coordinated works: installation over 4 to 8 weeks depending on power, prevention plan compliant with articles R4512-6 to R4512-12 governing interventions by external companies.
- Commissioning: hydraulic balancing, BMS configuration, training of operations technicians.
Measured results across the equipped stock: before / after comparison table
The average reduction in final heating consumption reaches 52% across the 60 commercial sites equipped by Kytom, within a range of 40 to 60% depending on the building envelope and the water loop temperature. A reference case illustrates the economic trajectory: a 4,200 m² head office in Lyon, fitted in 2022 with a 180 kW air-to-water heat pump, lowered its annual energy bill from 38,000 to 17,500 euros. The net return on investment reaches 6.8 years, after deducting CEE subsidies.
| Indicator | Before heat pump (gas) | After heat pump | Variation |
|---|---|---|---|
| Emission factor (gCO2 / kWh NCV) | 227 | 79 | -65% |
| Heating consumption (kWhFE / m².year) | 95 to 130 | 38 to 65 | -50% |
| Operating cost (euros / m².year) | 9 to 14 | 4 to 7 | -55% |
The BAT-TH-157 operation Energy Savings Certificates cover 18 to 25% of the investment cost. The performance contributes to CSRD reporting and to the valuation of environmental operating standards across the commercial building stock.
Technology trade-off: air-source, ground-source or VRF
The choice of technology depends on land availability, the temperature of the existing water loop and the investment budget. The table below summarises the trade-off criteria observed across the commercial building stock.
| Criterion | Air-to-water heat pump | Water-to-water geothermal heat pump | VRF (direct expansion) |
|---|---|---|---|
| Target SCOP | 3.8 to 4.2 | above 4.5 | 3.5 to 4.0 |
| Footprint | roof modules | vertical probes 80 to 150 m | compact outdoor unit |
| Investment (euros / kW) | 900 to 1,400 | 1,800 to 2,600 | 700 to 1,100 |
| Water supply temperature | 35 to 55 °C | 35 to 50 °C | not applicable (R32) |
| CEE BAT-TH-157 eligibility | yes | yes (BAT-TH-113) | yes |
Air-source remains predominant in commercial retrofits for its moderate installation cost and quick fitting. Ground-source is justified on sites with available parking or garden space, and an operating horizon above 25 years. VRF stands out in compartmentalised office floors where zone-by-zone control takes priority over domestic hot water production.
Technical limits: extreme cold, acoustics and high-temperature loop
Four points of vigilance, documented across the Kytom stock, must be factored in from the preliminary design stage.
- Performance in extreme cold: below -7 °C outdoor, the SCOP drops. An electric backup or a relay boiler remains necessary in the H1 zone to cover the coldest 5 to 8% of hours in the year.
- Outdoor unit noise: 52 to 68 dB(A) measured at 1 metre. A prior acoustic study is required in dense urban environments or near the openings of neighbouring offices, to comply with the neighbourhood noise order.
- Refrigerants: the F-Gas regulation revised in 2024 progressively phases out R410A (GWP 2,088) in favour of R32 (GWP 675) or R454B (GWP 466).
- High-temperature loop: connection to an existing 70 °C network reduces the SCOP by 25 to 35%, which justifies either a partial replacement of the emitters or a dedicated high-temperature heat pump.
Annual preventive maintenance requires a budget of 8 to 14 euros per kW installed, included from the operating contract onward.
Regulatory framework and declared performance requirements
Commercial heat pump installation falls within a strict regulatory framework that secures the performance declared to funders and authorities. The measurement of performance coefficients in static mode is regulated, with the seasonal SCOP defined over 4 operating points representative of climate zones H1, H2 and H3. CE marking and Eurovent certification lock in the catalogue values, a condition of eligibility for the CEE BAT-TH-157.
The calculation of heat losses relies on a standardised method, complemented by dynamic thermal simulation for buildings over 1,000 m². The neighbourhood noise order governs acoustic emergences, and the F-Gas regulation revised in 2024 constrains the choice of fluids. On the worksite side, the prevention plan falls under the regulatory articles R4512-6 to R4512-12 applicable to operations carried out by an external company. The certifications held by Kytom finalise the quality assurance framework, required by the majority of commercial clients.
Frequently asked questions
What SCOP should be expected from a commercial heat pump and how is it measured?
The instantaneous COP of a commercial air/water heat pump ranges from 2.8 to 4.8 depending on outdoor temperature and water flow temperature. The relevant regulatory figure remains the SCOP, measured under NF EN 14825 across 4 operating points representative of the climate zone. KYTOM sizes on a target SCOP of at least 3.5 for project validation, with a measured average of 3.8 to 4.2 in the H2 zone.
