Refrigerant GWP in Heat Pumps

Refrigerant GWP is the global warming potential of the working fluid inside a heat pump. It compares the warming effect of a refrigerant released into the atmosphere with the warming effect of carbon dioxide. The standard comparison normally covers 100 years and uses carbon dioxide as the reference value of 1.

GWP does not operate the heat pump or determine its efficiency. It measures the potential direct climate impact of refrigerant emissions. To use GWP, identify the refrigerant, confirm the refrigerant charge, apply the relevant GWP value, and convert any released quantity into carbon dioxide equivalent, or CO₂e.

The GWP value must not be assessed alone. A responsible heat-pump decision also considers refrigerant charge, leakage prevention, seasonal efficiency, safety, operating temperature, installation conditions, maintenance and end-of-life recovery.

What Is Refrigerant GWP?

Refrigerant GWP describes the potential warming effect of a refrigerant after it enters the atmosphere. It is a property of the refrigerant, not a performance rating for the heat pump. A higher number indicates a greater warming effect per kilogram released.

The term usually means GWP100. This value compares the accumulated warming effect over 100 years. CO₂ has a GWP of 1, which creates a common reference for different greenhouse gases.

Refrigerant GWP calculation

The basic calculation is:

Potential direct climate impact in kg CO₂e = refrigerant emitted in kg × GWP100

For tonnes of CO₂e:

Potential direct climate impact in t CO₂e = refrigerant emitted in kg × GWP100 ÷ 1,000

The calculation uses the amount actually emitted. A separate full-charge calculation can show the maximum direct climate exposure if the entire refrigerant charge were released. The European Commission also uses refrigerant mass multiplied by GWP to calculate tonnes of CO₂ equivalent.

Practical calculation example

Consider a heat pump containing 2 kg of R410A.

• R410A GWP under Regulation (EU) 2024/573: 2,088
• Refrigerant charge: 2 kg
• Full-charge climate exposure: 2 × 2,088 = 4,176 kg CO₂e
• Result: 4.176 tonnes CO₂e

Now consider a hypothetical system with the same 2 kg charge of R290 propane.

• R290 GWP under the same EU regulatory framework: 0.02
• Refrigerant charge: 2 kg
• Full-charge climate exposure: 2 × 0.02 = 0.04 kg CO₂e

These figures assume a complete release. They do not represent normal operation. Refrigerant should remain inside the sealed refrigeration circuit throughout the equipment’s operating life. The comparison only demonstrates how strongly the refrigerant type changes the potential direct climate impact.

GWP values can differ between sources

A refrigerant can have different published GWP values because scientific assessment reports and legal frameworks may use different datasets or calculation methods. The German Environment Agency publishes separate columns for IPCC assessment reports and Regulation (EU) 2024/573. For regulatory decisions, use the GWP value required by the applicable legislation rather than combining figures from different sources.

Core Purpose of Refrigerant GWP

The core purpose of GWP is to place different refrigerants on a common climate-impact scale. This supports comparison, regulation, equipment specification and emissions reporting.

Climate-impact comparison

Definition: GWP compares the warming effect of one refrigerant with CO₂.

Purpose: It allows very different gases to be assessed using the same reference.

Benefit: A planner can distinguish between a refrigerant with a low direct climate impact and one that could cause substantial CO₂e emissions after leakage.

Example: One kilogram of R410A represents 2,088 kg CO₂e under the current EU regulatory value. One kilogram of R290 represents 0.02 kg CO₂e.

Carbon dioxide equivalent calculation

Definition: CO₂e converts the climate effect of different greenhouse gases into a common unit.

Purpose: It makes refrigerant emissions compatible with carbon inventories and environmental reporting.

Benefit: Building owners can include refrigerant losses in organisational or property-level emissions records.

Example: A loss of 0.2 kg of R410A represents 417.6 kg CO₂e.

Regulatory classification

Definition: Refrigerant regulations use GWP thresholds to control gases and equipment.

Purpose: Legislators use these thresholds to reduce emissions from high-GWP fluorinated greenhouse gases.

Benefit: Manufacturers, planners and buyers can identify which technologies may face market restrictions during an asset’s expected lifetime.

Example: Current EU rules introduce several heat-pump restrictions at GWP thresholds of 150 and 750, depending on equipment type, capacity and date.

Equipment and portfolio planning

Definition: GWP becomes a procurement and asset-risk indicator when combined with refrigerant charge and regulatory timing.

Purpose: It helps buyers look beyond the purchase date and consider the full service life.

Benefit: Housing companies, hotel operators and commercial property owners can reduce exposure to changing refrigerant availability, servicing requirements and replacement pressure.

Example: A heat pump installed shortly before a future product restriction may still be legally operable, but its refrigerant could create longer-term service and supply concerns.

Why Refrigerant GWP Is Needed

Heat pumps can reduce heating-related emissions by transferring heat instead of producing all useful heat directly from fuel or electricity. However, every vapour-compression heat pump contains a refrigerant circuit. Leakage, poor servicing or incomplete end-of-life recovery can release part of that refrigerant.

GWP is needed because a small mass of high-GWP refrigerant can represent a large quantity of CO₂e. Without a standard measure, buyers could not compare the direct climate risks of R290, R32, R410A and other refrigerants.

The direct-emissions problem

The refrigerant is not normally consumed during heat-pump operation. It circulates between the compressor, heat exchangers, expansion device and connecting pipework. Direct emissions occur when refrigerant escapes during operation, servicing, repair, decommissioning or disposal.

The size of the direct impact depends on three main variables:

1. The refrigerant GWP.
2. The refrigerant charge.
3. The quantity released during the system life.

A low leakage rate remains important even with a low-GWP refrigerant. Preventing emissions also protects system performance, reliability and maintenance costs.

The regulatory problem

The EU is progressively reducing the amount of hydrofluorocarbons placed on the market. The current HFC quota schedule reduces the permitted quantity over time and reaches zero in 2050. EU rules also require measures such as qualified servicing personnel, leak checks for relevant equipment, refrigerant recovery and responsible end-of-life treatment.

Germany, Austria and Italy, including South Tyrol, operate within the EU F-gas framework. National authorities remain responsible for enforcement, certification procedures and penalties. Switzerland is outside the EU framework and applies separate refrigerant rules under its Chemical Risk Reduction Ordinance.

The business problem

A heat pump can remain in use for many years. A decision based only on today’s purchase price can overlook future refrigerant restrictions, servicing capability and component replacement.

Refrigerant GWP therefore supports several business decisions:

• Technical specifications for new developments.
• Environmental requirements in public and private tenders.
• Carbon-risk assessment for property portfolios.
• Maintenance and spare-parts planning.
• ESG and sustainability reporting.
• End-of-life recovery contracts.
• Replacement planning for older equipment.
• Avoidance of unsupported environmental claims.

The environmental-claims problem

“Environmentally friendly refrigerant” is too broad to be a reliable technical claim. A low GWP describes one environmental characteristic. It does not prove high energy efficiency, safe installation, low noise, low material impact or responsible disposal.

A credible claim identifies the exact refrigerant, GWP source, charge, equipment efficiency and lifecycle controls. It also states the assessment boundary. This prevents GWP from being used as a substitute for complete environmental performance.

Refrigerant GWP Regulation in the EU and DACH Region

European Union

Regulation (EU) 2024/573 entered into force on 11 March 2024. It covers fluorinated greenhouse-gas containment, use, recovery, certification, product restrictions, HFC quotas, labelling and reporting.

Selected heat-pump milestones under the current EU framework include:

The exact legal result depends on equipment construction, rated capacity, application, placing-on-the-market date and safety conditions. Annex IV of the regulation and applicable implementing measures remain the controlling legal sources.

A product prohibition normally concerns equipment being placed on the market. It does not automatically make every existing installation illegal. Existing systems can, however, be affected by separate servicing rules, refrigerant availability, technician requirements and recovery obligations. The German Environment Agency notes that tighter HFC quantity limits can reduce the availability of non-recycled or non-reclaimed gases for future maintenance and repair.

Switzerland

Switzerland regulates refrigerants through Annex 2.10 of the Chemical Risk Reduction Ordinance, known as ORRChem or ChemRRV. The framework addresses ozone-depleting refrigerants and refrigerants with strong climate effects. It also contains market restrictions for certain stationary heat-pump and refrigeration systems.

Swiss obligations can include:

• Restrictions based on refrigerant characteristics and equipment design.
• State-of-the-art requirements.
• Leakage checks.
• Maintenance records.
• Notification requirements.
• Rules for handling and servicing refrigerants.

FOEN states that stationary systems containing more than 3 kg of refrigerant are subject to the relevant reporting procedure. Switzerland has also published changes to Annex 2.10 that apply from 1 January 2027.

Key Features of Refrigerant GWP

Detailed Explanation of Refrigerant GWP Features

Relative climate-impact value

• Definition: GWP is a comparison factor. CO₂ is assigned a value of 1.
• Purpose: It creates one scale for gases with different atmospheric behaviour.
• Benefit: Refrigerant options can be compared without using different units.
• Example: R744 is CO₂ itself and has a GWP of 1. R32 has an EU regulatory GWP of 675.

Defined assessment period

• Definition: GWP normally uses a 100-year assessment period.
• Purpose: The time horizon captures both warming strength and atmospheric persistence.
• Benefit: Comparable assessments use the same reference period.
• Example: A product specification should state “GWP100” rather than only “GWP” when the source is not otherwise clear.

Dependence on refrigerant mass

• Definition: GWP describes impact per unit of mass. Total CO₂e depends on the quantity released.
• Purpose: It connects refrigerant properties with real equipment design and leakage.
• Benefit: A buyer can compare both the refrigerant type and the charge required by the system.
• Example: A system containing 1 kg of a refrigerant has half the full-charge CO₂e exposure of an otherwise identical system containing 2 kg of the same refrigerant.

Dependence on leakage

• Definition: Refrigerant inside an intact circuit has not yet become a direct atmospheric emission.
• Purpose: Leakage calculations distinguish installed refrigerant inventory from actual emissions.
• Benefit: Maintenance records can reflect real additions, losses and recovered quantities.
• Example: A 5% loss from a 2 kg R410A charge equals 0.1 kg released, or 208.8 kg CO₂e.

Pure refrigerants and refrigerant blends

• Definition: A pure refrigerant contains one principal substance. A blend combines several components.
• Purpose: Blends can provide selected pressure, temperature and performance characteristics.
• Benefit: Manufacturers can optimise a refrigeration cycle for a defined application.
• Example: R410A is a blend of HFC-32 and HFC-125. Its EU regulatory GWP is 2,088.

Blend handling must follow the equipment manufacturer’s instructions. Some blends have temperature glide or composition-related servicing requirements. A refrigerant must not be treated as interchangeable with another refrigerant solely because the pressure or GWP appears similar.

Direct and indirect climate impacts

• Definition: Direct emissions come from released refrigerant. Indirect emissions are mainly associated with the energy used to operate the heat pump.
• Purpose: The distinction prevents a refrigerant metric from being mistaken for a whole-system metric.
• Benefit: Decision-makers can reduce both leakage-related and energy-related emissions.
• Example: A low-GWP heat pump with poor seasonal efficiency can use more electricity than a well-designed alternative. GWP alone cannot show the better lifecycle result.

The Total Equivalent Warming Impact, or TEWI, combines estimated refrigerant emissions with energy-related CO₂ emissions. A broader lifecycle assessment can also include manufacturing, materials and end-of-life effects.

Separation from refrigerant safety

• Definition: Refrigerant safety classifications consider toxicity and flammability. GWP does not.
• Purpose: Safety classification identifies engineering controls needed for installation and operation.
• Benefit: Low climate impact can be achieved without ignoring occupants, installers or emergency responders.
• Example: R290 has a very low GWP but requires controls appropriate to a flammable hydrocarbon refrigerant.

ISO 817 provides a refrigerant designation and safety-classification system based on toxicity and flammability data. The European Commission also states that no single refrigerant is suitable for every application because thermodynamic properties, safety and location differ.

Dependence on the selected GWP source

• Definition: A GWP value is linked to a named scientific or regulatory source.
• Purpose: The source defines which value must be used in a calculation.
• Benefit: Compliance documents, tenders and carbon reports remain internally consistent.
• Example: The German Environment Agency lists R290 as 3.3 under the IPCC Fourth Assessment Report column and 0.02 under the Regulation (EU) 2024/573 column. The applicable regulatory column should be used for an EU F-gas compliance calculation.

Types of Heat-Pump Refrigerants by GWP

Natural or non-fluorinated refrigerants

Definition: Natural refrigerants are an industry group that includes substances such as hydrocarbons, carbon dioxide and ammonia.

Purpose: They provide alternatives to fluorinated refrigerants with high GWP.

Benefits: Their regulatory GWP values are generally very low. They can reduce the direct climate exposure of a refrigerant charge.

Examples: R290 propane, R744 carbon dioxide and R717 ammonia.

The term “natural” does not remove the need for engineered safety controls. Propane is flammable. Ammonia requires toxicity controls. Carbon dioxide systems operate with specialised pressure and cycle requirements.

Hydrofluorocarbons

Definition: HFCs are synthetic fluorinated gases containing hydrogen, fluorine and carbon.

Purpose: They replaced many ozone-depleting refrigerants in refrigeration and heat-pump applications.

Benefits: HFCs enabled established system architectures and broad service experience.

Examples: R32 and R134a. R410A and R407C are blends containing HFC components.

Many HFCs have medium or high GWP. They are therefore affected by the EU HFC quota reduction and by equipment-specific market restrictions.

Hydrofluoroolefins and HFO-containing blends

Definition: HFOs are unsaturated fluorinated substances. They can be used alone or blended with HFCs.

Purpose: They support lower-GWP synthetic refrigerant options.

Benefits: Some HFOs and HFO-containing blends have substantially lower GWP than legacy HFC refrigerants.

Examples: R1234ze(E), R454B, R454C and R452B.

A lower-GWP blend can still be a fluorinated greenhouse gas within the scope of F-gas rules. Its long-term regulatory position depends on the exact substance, equipment category and prohibition wording.

Common refrigerant GWP comparison

The following values use the GWP100 figures applicable under Regulation (EU) 2024/573, as compiled by the German Environment Agency in March 2026.

GWP values are not product-efficiency ratings. The table also does not establish that one refrigerant is suitable for every building or system architecture.

GWP threshold language

Terms such as “low GWP” and “high GWP” do not have one universal boundary for every purpose. EU legislation uses specific limits such as 150 and 750 for defined equipment categories. These are legal trigger values, not universal environmental grades.

A clear specification should therefore state the actual number:

• Better: “Refrigerant GWP100: 0.02 under Regulation (EU) 2024/573.”
• Less precise: “Uses an eco-friendly refrigerant.”

Refrigerant GWP Use Cases

Residential new construction

Definition: A new residential project selects the heat pump before construction or major building-services installation.

Purpose: The planner can coordinate refrigerant technology, equipment location, heating-load calculation and low-temperature emitters.

Benefit: Regulatory and safety requirements can be included before structural or landscape decisions become fixed.

Example: An outdoor monoblock heat pump can be assessed for refrigerant GWP, boundary clearances, sound, flow temperature and hydraulic integration as one design package.

Residential renovation

Definition: A renovation replaces an existing boiler or older heat pump while retaining some existing building systems.

Purpose: The refrigerant decision must be combined with radiator temperatures, insulation level and available outdoor or plant-room space.

Benefit: The project avoids choosing a refrigerant only by GWP while overlooking whether the heat pump can deliver the required seasonal performance.

Example: A low-GWP heat pump may be suitable, but the designer must still verify output and efficiency at the required winter flow temperature.

Apartment buildings and housing portfolios

Definition: One owner operates multiple dwellings or several heat-generating assets.

Purpose: A portfolio assessment standardises GWP, charge, maintenance and replacement data.

Benefit: The owner can identify which systems carry the greatest direct-emissions and servicing exposure.

Example: A housing company can record refrigerant type, charge, installation year, leakage history and planned replacement date in its asset database.

Hotels and buildings with high hot-water demand

Definition: These buildings require frequent or continuous domestic hot-water production.

Purpose: Refrigerant selection must support the necessary temperature range and operating profile.

Benefit: The operator can compare direct refrigerant impact without compromising hot-water capacity or efficiency.

Example: A hotel project may compare R290 and R744-based solutions, but the final decision must include output, temperature lift, space, noise, hydraulics and service capability.

Commercial and industrial heat pumps

Definition: Larger heat pumps serve process heat, district energy, commercial hot water or industrial heating.

Purpose: GWP assessment supports refrigerant inventory management and large-system environmental planning.

Benefit: Low-GWP refrigerants can substantially reduce full-charge CO₂e exposure where refrigerant charges are large.

Example: An industrial project may evaluate ammonia, carbon dioxide, hydrocarbons or lower-GWP synthetic options according to process temperature, safety zoning and operator competence.

Public and private procurement

Definition: A tender defines minimum technical and environmental requirements before suppliers submit offers.

Purpose: A GWP requirement prevents vague refrigerant claims.

Benefit: All bidders provide comparable data.

Example tender fields include:

• Refrigerant designation.
• Refrigerant family.
• GWP100 and named source.
• Factory refrigerant charge.
• Full-charge t CO₂e.
• Safety classification.
• Seasonal efficiency.
• Installation requirements.
• Leak-prevention measures.
• Recovery and end-of-life procedure.

Maintenance and replacement planning

Definition: Existing equipment is assessed during servicing or before major repair.

Purpose: The assessment determines whether continued operation, repair or replacement is the better lifecycle decision.

Benefit: The owner avoids emergency decisions after refrigerant loss or compressor failure.

Example: An older R410A heat pump may remain operational, but its charge, condition, repair cost, energy performance and expected refrigerant availability should be assessed together.

Benefits of a Low-GWP Refrigerant Strategy

Lower potential direct emissions

A lower GWP reduces the CO₂e impact of each kilogram released. This benefit applies during accidental leakage, servicing losses and incomplete end-of-life recovery.

The best result combines:

• Low refrigerant GWP.
• Low refrigerant charge.
• Leak-tight equipment.
• Correct installation.
• Professional maintenance.
• High recovery rates.

Greater regulatory resilience

Equipment using a refrigerant below an upcoming GWP threshold may face fewer direct conflicts with that specific threshold. Non-fluorinated alternatives are also outside product prohibitions written specifically around fluorinated greenhouse-gas content.

Regulatory resilience is not the same as permanent exemption. Safety rules, product standards, building regulations and future environmental requirements continue to apply.

Reduced refrigerant supply exposure

The EU HFC quota reduces the amount of HFC refrigerant that can be placed on the market. Systems that depend on higher-GWP HFCs can therefore create greater long-term supply and servicing concerns.

A lower-exposure strategy can support:

• More predictable maintenance planning.
• Reduced dependence on high-GWP virgin refrigerant.
• Easier portfolio transition.
• Better alignment with future procurement policies.

More transparent carbon reporting

GWP allows direct refrigerant emissions to be reported in CO₂e. This gives property owners a repeatable method for recording losses and refrigerant additions.

Useful records include:

• Opening refrigerant inventory.
• Refrigerant added during service.
• Refrigerant recovered.
• Refrigerant sent for recycling or reclamation.
• Unexplained losses.
• Calculated CO₂e emissions.

Stronger environmental product positioning

A stated GWP value is more credible than a general “green refrigerant” statement. It allows customers and project teams to verify the claim against an official source.

A complete product position should combine:

• Refrigerant GWP.
• Refrigerant charge.
• Seasonal efficiency.
• Applicable safety concept.
• Expected service life.
• Repairability.
• Responsible end-of-life recovery.

Better long-term asset decisions

Heat-pump procurement affects operating costs and maintenance for many years. GWP information helps owners consider changes that may occur after installation.

This supports better decisions about:

• New equipment.
• Major repair.
• Refrigerant-circuit replacement.
• Portfolio standardisation.
• Planned obsolescence risk.
• Decommissioning.

How to Select a Heat Pump Using Refrigerant GWP

There is no universally best refrigerant for every heat pump. Location, output, heat source, temperature requirement, system architecture, safety and efficiency all affect suitability. The European Commission specifically notes that refrigerant alternatives must be assessed by equipment category and, in some cases, by geographical location.

Step-by-step GWP assessment

Step 1: Identify the exact refrigerant

Use the full refrigerant designation from the technical datasheet or nameplate. Do not rely on terms such as “low-GWP refrigerant” without a refrigerant number.

Examples include:

• R290.
• R32.
• R454C.
• R407C.
• R410A.

Step 2: Record the factory refrigerant charge

Find the charge in kilograms. For field-connected systems, include any additional charge required for installed pipe length.

The refrigerant charge determines the full-charge climate exposure. Two products using the same refrigerant can have different CO₂e values because their charges differ.

Step 3: Confirm the applicable GWP value

Use the value required in the project jurisdiction and for the intended calculation. Record the source and assessment period.

For EU compliance, identify the value used under Regulation (EU) 2024/573. For Switzerland, follow the applicable ORRChem definitions and FOEN guidance.

Step 4: Calculate full-charge CO₂e

Use:

Charge in kg × GWP ÷ 1,000 = full-charge tonnes CO₂e

This is a potential exposure value. It is not an assumption that the entire charge will leak.

Step 5: Estimate lifecycle refrigerant emissions

Consider:

• Manufacturing and factory charging losses where data are available.
• Expected operational leakage.
• Service losses.
• Refrigerant added after repairs.
• Refrigerant recovered at end of life.
• Unrecovered remaining charge.

Use documented project assumptions rather than a generic percentage where reliable service records are available.

Step 6: Check market restrictions

Verify:

• Equipment category.
• Rated capacity.
• Self-contained or split construction.
• Refrigerant GWP.
• Intended placing-on-the-market date.
• Safety exceptions.
• National enforcement requirements.

A model that is available today may not be the correct choice for a project delivered after a future restriction date.

Step 7: Evaluate refrigerant safety

Check the applicable refrigerant safety classification and product installation instructions. Assess occupied spaces, outdoor placement, ventilation, ignition sources, service access and minimum clearances.

GWP cannot replace this safety assessment. ISO 817 classifies refrigerants using toxicity and flammability criteria.

Step 8: Compare real operating efficiency

Review efficiency at the project’s design conditions, not only at a favourable standard point.

Assess:

• COP at relevant source and flow temperatures.
• SCOP for the applicable climate.
• Expected seasonal performance factor.
• Auxiliary energy.
• Defrost operation.
• Domestic hot-water efficiency.
• Backup-heater use.
• Part-load behaviour.

Step 9: Review service capability

Confirm that trained personnel, suitable tools and replacement components are available in the region. Refrigerant recovery and handling must follow applicable legal and technical requirements.

The EU framework requires qualified personnel for relevant maintenance and servicing activities and requires recovery at end of life.

Step 10: Plan end-of-life recovery

The project specification should identify who is responsible for refrigerant recovery when the system is replaced. The recovered fluid should be reused, recycled, reclaimed or destroyed through an authorised route as applicable.

Heat-pump selection checklist

Selection red flags

Treat the following statements cautiously:

• “GWP does not matter because heat pumps never leak.”
• “The lowest-GWP refrigerant is automatically the best product.”
• “A low GWP proves low electricity consumption.”
• “All natural refrigerants are risk-free.”
• “Any refrigerant can replace an older refrigerant.”
• “An existing system becomes illegal as soon as a new-product ban begins.”
• “A GWP value is valid without naming its source.”
• “Refrigerant charge does not matter when GWP is low.”

Refrigerant GWP Comparisons

GWP compared with other heat-pump metrics

GWP versus CO₂e

GWP is a factor. CO₂e is the result after applying that factor to a mass.

• GWP: R32 = 675.
• Mass released: 1.5 kg.
• CO₂e: 1.5 × 675 = 1,012.5 kg CO₂e.

This distinction is important in specifications. A product should not list “675 kg CO₂e” unless the corresponding released mass is also defined.

GWP versus refrigerant charge

A low refrigerant charge reduces the quantity that could be released. A low GWP reduces the warming effect of each released kilogram.

The strongest direct-emissions strategy normally combines both:

Low GWP × low charge × low leakage × high recovery

A product with a low charge of a high-GWP refrigerant can still have a substantial full-charge CO₂e value. A product with a low-GWP refrigerant still requires leak-tight construction and correct service.

GWP versus heat-pump efficiency

GWP and efficiency answer different questions.

• GWP asks: What is the potential impact if refrigerant is emitted?
• COP asks: How efficiently does the heat pump operate at one condition?
• SCOP asks: How efficiently does it perform across a standard season?
• Seasonal performance factor asks: How efficiently does the installed system perform over time?

A complete environmental comparison uses both direct and indirect emissions. ASHRAE recommends lifecycle methods that consider efficiency, direct emissions, indirect emissions, safety and end-of-life effects together.

GWP versus ODP

Global warming potential and ozone depletion potential are separate environmental properties.

• GWP concerns climate warming.
• ODP concerns damage to the stratospheric ozone layer.

A refrigerant can have zero ODP and still have a high GWP. The replacement of ozone-depleting refrigerants therefore did not remove the need to address the climate effects of HFCs.

R290 versus R32 versus R410A

R32 has substantially lower GWP than R410A, but it remains above the GWP 150 threshold used in several future EU equipment restrictions. R290 has a far lower direct climate impact, but its flammability requires a product and installation specifically engineered for propane.

Monoblock versus split heat pumps

A self-contained or monoblock heat pump has a factory-completed refrigerant circuit. No gas-containing parts are connected at the installation site. A split heat pump has indoor and outdoor units connected by refrigerant pipework during installation.

The architecture affects installation and regulatory classification, but it does not determine GWP. Either architecture can use different refrigerants.

A monoblock design may keep the refrigerant circuit outside occupied space, depending on the product. This can support some safety concepts, but it does not remove the need to follow clearances, siting instructions and local requirements.

Natural versus synthetic refrigerants

Natural and synthetic refrigerants should not be compared only by name.

Integration of Refrigerant GWP with Other Heat-Pump Systems

Refrigerant selection is one part of heat-pump system design. The best environmental outcome comes from integrating the refrigerant circuit with the building, heat source, hydraulic system, controls and service strategy.

Building heating-load calculation

Definition: The heating-load calculation establishes the output required at the local design temperature.

Purpose: It prevents oversizing and undersizing.

Benefit: Correct sizing supports efficient operation, stable cycling and suitable refrigerant-charge selection.

Example: A well-insulated house may require a smaller heat pump and potentially less refrigerant than an oversized design.

Heating emitters and flow temperature

Definition: Emitters include underfloor heating, fan coils and radiators.

Purpose: They transfer heat from the water circuit to the building.

Benefit: Adequately sized emitters can operate at lower flow temperatures, reducing the temperature lift required from the heat pump.

Example: Enlarging selected radiators can improve seasonal performance without changing refrigerant GWP.

This illustrates an important boundary: refrigerant GWP affects direct emissions. Flow temperature and system design mainly affect electricity consumption and indirect emissions.

Domestic hot-water production

Definition: The heat pump transfers heat to a cylinder, fresh-water module or other hot-water system.

Purpose: It supplies hygienic and reliable domestic hot water.

Benefit: Correct storage volume, temperature strategy and control reduce unnecessary high-temperature operation.

Example: A system may use scheduled hot-water charging rather than maintaining the maximum temperature continuously.

Hydraulic storage and distribution

Definition: The hydraulic system includes pumps, valves, pipework, buffer storage and heating circuits.

Purpose: It delivers heat at the required flow and temperature.

Benefit: Good hydraulic design reduces cycling, auxiliary electricity and avoidable temperature peaks.

Example: A correctly designed volume and control strategy can stabilise operation without using an oversized buffer tank.

Building and energy-management controls

Definition: Controls coordinate heat generation, room demand, hot water and other energy systems.

Purpose: They operate the heat pump according to real demand.

Benefit: Better control can reduce energy use while maintaining comfort.

Example: Weather-compensated control adjusts flow temperature as outdoor conditions change. GWP remains unchanged, but total lifecycle emissions can fall through lower electricity consumption.

Photovoltaics and flexible electricity use

Definition: A photovoltaic system produces electricity at the building.

Purpose: Heat-pump controls can shift suitable loads toward periods of local generation or favourable grid conditions.

Benefit: Self-consumption and operating-cost performance can improve.

Example: The heat pump can charge domestic hot water or use building thermal mass during periods of available photovoltaic output, subject to comfort and efficiency limits.

PV integration does not change refrigerant GWP. It affects the energy-related side of total climate performance.

Monitoring and maintenance

Definition: Monitoring identifies faults, unusual operating patterns and performance changes.

Purpose: It supports early intervention.

Benefit: Problems can be corrected before they cause prolonged inefficiency or refrigerant-circuit damage.

Example: Persistent pressure or temperature abnormalities can trigger a technical inspection rather than allowing degraded operation to continue.

Responsible refrigerant management also includes commissioning, leak prevention, record keeping, recovery, recycling, reclamation and safe disposal.

Carbon and ESG systems

Definition: Building owners use carbon-management systems to track operational and direct emissions.

Purpose: Refrigerant records add direct emissions to the wider building inventory.

Benefit: Environmental reporting becomes more complete and auditable.

Example: A property portfolio can calculate annual refrigerant CO₂e from documented service additions rather than estimating all emissions from equipment age.

Procurement and BIM integration

Definition: Procurement systems and building information models store technical product data.

Purpose: Refrigerant information remains available after the original project team leaves.

Benefit: Operators can retrieve the refrigerant type, charge, GWP and service requirements during maintenance or replacement.

Recommended data fields include:

• Refrigerant designation.
• GWP100.
• GWP source.
• Factory charge.
• Installed charge.
• Full-charge t CO₂e.
• Safety classification.
• Installation restrictions.
• Commissioning date.
• Service history.
• Recovery instructions.

Refrigerant GWP and iDM Energiesysteme GmbH

For an iDM Energiesysteme project, refrigerant GWP should be used as one criterion within a complete heat-pump assessment. A low GWP is valuable, but the building still needs the correct heat output, operating temperature, heat source, hydraulic system and control strategy.

A strong environmental specification combines:

1. A refrigerant with an appropriate and documented GWP.
2. A refrigerant charge suited to the product design.
3. High seasonal heat-pump efficiency.
4. Correct sizing for the building.
5. Low and stable system temperatures where practicable.
6. Intelligent energy management.
7. Professional installation and commissioning.
8. Leak prevention and qualified service.
9. Responsible refrigerant recovery at end of life.

This system-level approach creates a more credible product position than promoting one refrigerant value in isolation. It addresses both direct refrigerant emissions and indirect energy-related emissions.

For homeowners, the result is a clearer purchasing decision. For planners, it creates a defensible technical specification. For housing companies and commercial operators, it supports long-term compliance, maintenance and carbon management.

Refrigerant GWP Decision Framework

Use the following order when comparing heat pumps:

1. Confirm the building requirement.
   Calculate the heating load, hot-water demand and required flow temperature.
2. Identify suitable heat-pump architectures.
   Compare heat source, output, monoblock or split construction, space and sound requirements.
3. Record refrigerant data.
   Identify the refrigerant, GWP source and installed charge.
4. Calculate full-charge CO₂e.
   Use charge × GWP ÷ 1,000.
5. Check current and future legal requirements.
   Consider the expected product delivery date and service life.
6. Verify the safety concept.
   Follow refrigerant classification, product instructions and local installation rules.
7. Compare seasonal efficiency.
   Use project-relevant source and flow temperatures.
8. Review service and recovery.
   Confirm technician availability, maintenance requirements and end-of-life responsibility.
9. Assess lifecycle performance.
   Consider both direct and energy-related emissions.
10. Document the decision.
    Keep the technical evidence with the building and asset records.

Refrigerant GWP measures the potential climate effect of a heat-pump refrigerant relative to CO₂. It converts refrigerant emissions into CO₂e and supports comparison, regulation, procurement and carbon reporting.

A lower GWP reduces the direct climate impact of each kilogram released. It does not independently prove that a heat pump is efficient, safe or suitable for a building. The complete decision must include refrigerant charge, leakage prevention, legal status, seasonal efficiency, required temperatures, installation conditions, service capability and end-of-life recovery.

For iDM Energiesysteme GmbH, refrigerant GWP fits within a wider heat-pump environment strategy. The strongest position combines responsible refrigerant technology with efficient system design, intelligent control, professional installation and lifecycle service.

Frequently Asked Questions About Refrigerant GWP

What does GWP mean on a heat pump?

GWP means global warming potential. It shows the potential warming effect of the heat pump’s refrigerant compared with CO₂, normally over 100 years. It does not show the heat pump’s energy efficiency.

What is considered a good refrigerant GWP?

A lower value generally indicates a lower direct warming effect per kilogram released. There is no universal “good” boundary for every application. EU equipment restrictions commonly use thresholds such as 150 and 750, but these limits depend on equipment type, capacity, date and safety conditions.

Does a GWP of 1 mean no climate impact?

No. A GWP of 1 means that one kilogram has the reference warming effect of one kilogram of CO₂ over the specified time horizon. R744 is CO₂ and therefore has a GWP of 1.

Can refrigerant GWP be zero?

Some refrigerants have a regulatory GWP listed as zero. R717 ammonia is one example in the current EU regulatory table. A zero GWP does not mean that the complete heat-pump system has zero environmental impact.

Does low GWP reduce heat-pump electricity use?

Not directly. GWP measures potential direct refrigerant impact. Electricity use depends on heat-pump design, source temperature, flow temperature, controls, building load and installation quality.

Is R290 always better than R32?

R290 has a much lower GWP. However, the correct selection also depends on product architecture, flammability controls, site conditions, output, efficiency and service support. R290 is not an automatic replacement for R32 in equipment designed for another refrigerant.

Is R32 a low-GWP refrigerant?

R32 has a GWP of 675 under the current EU regulatory value. This is much lower than R410A at 2,088 but higher than the GWP 150 threshold used in several future EU product restrictions. It is best described precisely as lower-GWP than R410A, rather than universally “low GWP.”

Is R410A being banned?

EU rules progressively restrict new equipment containing higher-GWP F-gases. The applicable date depends on equipment construction and capacity. Existing R410A equipment is not automatically made illegal by a prohibition on placing new products on the market, but servicing and refrigerant-supply conditions can become more restrictive.

Does a heat pump release refrigerant during normal operation?

A correctly functioning heat pump circulates refrigerant inside a closed circuit. Refrigerant release is not an intended part of operation. Emissions can occur through faults, leakage, service work or poor end-of-life handling.

Is refrigerant charge as important as GWP?

Yes. Total potential direct impact depends on both. A high-GWP refrigerant with a small charge and the same refrigerant with a large charge have different full-charge CO₂e values.

How do I calculate the CO₂e of a heat pump?

Multiply the refrigerant charge in kilograms by the GWP. Divide by 1,000 to express the result in tonnes.

For example:

1.8 kg R32 × 675 ÷ 1,000 = 1.215 t CO₂e

This represents the full-charge climate exposure, not an assumption of actual leakage.

Which GWP value should be used?

Use the value specified by the relevant regulation, reporting standard or contract. State the GWP source and time horizon. Do not combine an IPCC value for one refrigerant with an EU regulatory value for another without explaining the difference.

Can an old heat pump be filled with a lower-GWP refrigerant?

Not automatically. Refrigerants have different pressure, temperature, lubricant, material and safety characteristics. A refrigerant change requires manufacturer approval, an engineered conversion procedure and legal compliance. An unofficial substitution can create safety, reliability and warranty problems.