<\/span><\/h2>\nA heat pump is part of a complete heating system. Its environmental result does not come from the outdoor or indoor unit alone.<\/p>\n
The operational chain is:<\/p>\n
Building heat demand \u2192 required flow temperature \u2192 selected heat source \u2192 heat pump performance \u2192 electricity consumption \u2192 electricity emissions \u2192 refrigerant effects \u2192 maintenance and end-of-life treatment<\/strong><\/p>\nA weak link can reduce the performance of the entire system. For example, an efficient heat pump can still consume excessive electricity when it is oversized, operated at an unnecessarily high flow temperature or connected to an unsuitable hydraulic system.<\/p>\n
How to test an environmental claim<\/h3>\n
Use the following process:<\/p>\n
\n- Define the claim.<\/strong>
Identify whether it concerns energy, carbon, noise, refrigerants, cost or grid demand.<\/li>\n- Set the system boundary.<\/strong>
Decide whether the comparison covers the product, the heating system, annual operation or the full lifecycle.<\/li>\n- Use delivered heat as the functional unit.<\/strong>
Compare emissions and energy per kilowatt-hour of useful heat, not per kilowatt-hour of fuel or electricity input.<\/li>\n- Use seasonal performance.<\/strong>
Do not base an annual conclusion on one laboratory COP value.<\/li>\n- Use location-specific inputs.<\/strong>
Apply the local design temperature, electricity-emission factor, planning requirements and noise limits.<\/li>\n- Check installation conditions.<\/strong>
Review sizing, hydraulic balance, emitters, controls, sound propagation and refrigerant handling.<\/li>\n- Verify the result after commissioning.<\/strong>
Compare measured heat output, total electricity input, operating temperatures and backup-heater use.<\/li>\n<\/ol>\n<\/span>Key features of a reliable environmental assessment<\/span><\/h2>\nA defined system boundary<\/h3>\n
Definition.<\/strong> The system boundary identifies which environmental effects are included. A narrow boundary may include only electricity during operation. A lifecycle boundary also includes manufacturing, transport, refrigerant losses, maintenance and end-of-life treatment.<\/p>\nPurpose.<\/strong> It prevents a comparison between unlike measurements. \u201cNo on-site combustion\u201d is not the same as \u201czero lifecycle emissions.\u201d<\/p>\nBenefit.<\/strong> A defined boundary creates transparent and repeatable environmental claims.<\/p>\nPractical application.<\/strong> State whether a carbon figure covers operational electricity only or full lifecycle carbon dioxide equivalent, expressed as CO\u2082e.<\/p>\nSeasonal performance<\/h3>\n
Definition.<\/strong> Seasonal performance describes heat output relative to electricity use over an extended operating period. Common terms include SCOP and seasonal performance factor, known as the Jahresarbeitszahl<\/em> or JAZ in German-speaking markets.<\/p>\nPurpose.<\/strong> It accounts for changing outdoor temperatures, hot-water production, circulation pumps, defrosting and part-load operation.<\/p>\nBenefit.<\/strong> Seasonal data provide a more realistic estimate of annual electricity demand than one COP test point.<\/p>\nPractical application.<\/strong> Request the expected seasonal performance at the building\u2019s actual flow temperature. Define which pumps, controls and backup heaters are included in the calculation boundary.<\/p>\nTemperature lift<\/h3>\n
Definition.<\/strong> Temperature lift is the difference between the heat-source temperature and the required heating-system temperature.<\/p>\nPurpose.<\/strong> It explains why source conditions and flow temperature strongly affect efficiency.<\/p>\nBenefit.<\/strong> Reducing the temperature lift can lower electricity consumption without changing the heat pump.<\/p>\nPractical application.<\/strong> Improve radiator output, hydraulic balance and heating-curve settings before increasing the flow temperature.<\/p>\nElectricity-emission intensity<\/h3>\n
Definition.<\/strong> Electricity-emission intensity describes the greenhouse gas emissions associated with one kilowatt-hour of electricity.<\/p>\nPurpose.<\/strong> It connects heat pump electricity consumption with operational climate impact.<\/p>\nBenefit.<\/strong> It allows consistent comparison between countries, electricity products and operating periods.<\/p>\nPractical application.<\/strong> Divide the relevant electricity-emission factor by the seasonal performance factor to estimate emissions per kilowatt-hour of delivered heat. Add refrigerant and embodied effects when conducting a lifecycle comparison.<\/p>\nRefrigerant impact<\/h3>\n
Definition.<\/strong> Refrigerant impact depends on the refrigerant charge, Global Warming Potential or GWP, leakage, servicing and recovery at end of life.<\/p>\nPurpose.<\/strong> It separates direct refrigerant emissions from indirect electricity-related emissions.<\/p>\nBenefit.<\/strong> It supports lower-GWP product selection without ignoring system efficiency or safety.<\/p>\nPractical application.<\/strong> Review the refrigerant type, total charge, circuit design, service requirements, leak-prevention measures and end-of-life recovery process.<\/p>\nAcoustic impact<\/h3>\n
Definition.<\/strong> Acoustic impact includes the sound emitted by the heat pump and the sound level received at neighbouring or occupied locations.<\/p>\nPurpose.<\/strong> It distinguishes sound power from sound pressure. Sound power is a product characteristic. Sound pressure depends on distance, direction, reflections, barriers and surroundings.<\/p>\nBenefit.<\/strong> Early acoustic planning protects occupants and neighbours and avoids expensive corrective work.<\/p>\nPractical application.<\/strong> Use declared sound-power data in a site-specific sound calculation. Include night operation, reflective walls, corners, elevation and the nearest protected room.<\/p>\nHeat-source and site impact<\/h3>\n
Definition.<\/strong> The heat source may be outdoor air, ground, groundwater, surface water, exhaust air or recoverable waste heat.<\/p>\nPurpose.<\/strong> It identifies source-specific benefits, limitations, pumping energy and approval requirements.<\/p>\nBenefit.<\/strong> It prevents the assumption that one heat source is environmentally superior in every location.<\/p>\nPractical application.<\/strong> Compare seasonal efficiency, construction impact, geology, water protection, land use, noise and permitting before selecting the source.<\/p>\nMeasured system performance<\/h3>\n
Definition.<\/strong> Measured performance compares total delivered heat with total electrical input after the system enters operation.<\/p>\nPurpose.<\/strong> It confirms whether product selection, installation and controls produce the intended result.<\/p>\nBenefit.<\/strong> Monitoring detects excessive flow temperatures, backup-heater use, short cycling and control errors.<\/p>\nPractical application.<\/strong> Record heat-meter and electricity-meter data. Review seasonal performance, compressor starts, heating curves, hot-water temperatures and auxiliary energy.<\/p>\n<\/span>Common heat pump environmental myths: detailed fact check<\/span><\/h2>\nMyth 1: \u201cA heat pump with an efficiency above 100% violates the laws of physics\u201d<\/h3>\n
Verdict:<\/strong> False.<\/p>\nDefinition of the myth.<\/strong> The claim treats the coefficient of performance as if it were the combustion efficiency of a boiler.<\/p>\nPurpose of the correction.<\/strong> A heat pump does not convert electricity directly into all the delivered heat. Electricity operates the compressor and associated components. The system also transfers energy from air, ground or water.<\/p>\nBenefit.<\/strong> Correct interpretation allows heat pumps, boilers and resistance heaters to be compared without confusing different energy processes.<\/p>\nPractical application.<\/strong> A COP of 4 can represent one unit of electricity plus approximately three units of transferred environmental heat, producing four units of useful heat. Energy is conserved because the delivered heat equals the electrical input plus the heat taken from the source. The IEA describes a typical household heat pump COP of around four and notes that output is normally several times the electrical input.<\/p>\nMyth 2: \u201cHeat pumps are not renewable because they use electricity\u201d<\/h3>\n
Verdict:<\/strong> The statement is incomplete.<\/p>\nDefinition of the myth.<\/strong> The claim assumes that any technology using electricity must be classified as non-renewable.<\/p>\nPurpose of the correction.<\/strong> A heat pump combines electrical drive energy with heat taken from an ambient, aerothermal, geothermal or hydrothermal source. These environmental heat sources are recognised within the EU renewable-energy framework.<\/p>\nBenefit.<\/strong> The correction separates the renewable heat source from the electricity used to operate the system.<\/p>\nPractical application.<\/strong> Do not describe every unit of heat as automatically renewable. The calculated renewable contribution depends on applicable methodology and system performance. Electricity-related emissions must still be included in a carbon assessment.<\/p>\nMyth 3: \u201cEvery heat pump is automatically zero-carbon\u201d<\/h3>\n
Verdict:<\/strong> False.<\/p>\nDefinition of the myth.<\/strong> The claim equates the absence of on-site combustion with the absence of all greenhouse gas emissions.<\/p>\nPurpose of the correction.<\/strong> An electric heat pump normally produces no direct combustion emissions at the building. Its full climate impact can still include electricity generation, manufacturing, transport, refrigerant losses, servicing and end-of-life treatment.<\/p>\nBenefit.<\/strong> This distinction prevents unsupported terms such as \u201ccompletely emission-free\u201d or \u201cfully carbon neutral.\u201d<\/p>\nPractical application.<\/strong> Use precise wording:<\/p>\n\n- \u201cNo on-site fuel combustion\u201d<\/li>\n
- \u201cLow operational emissions under the stated electricity and performance assumptions\u201d<\/li>\n
- \u201cReduced lifecycle emissions compared with the defined reference system\u201d<\/li>\n<\/ul>\n
The IEA notes that refrigerant leakage can reduce the climate benefit, while environmental authorities distinguish operational emissions from other lifecycle effects.<\/p>\n
Myth 4: \u201cElectricity from the grid makes a heat pump worse than a gas boiler\u201d<\/h3>\n
Verdict:<\/strong> This is not a valid general rule.<\/p>\n