1.1 Scope
Air to air heat pumps are products that are specifically designed to transfer heat from the air in one space to the air within another space by means of a refrigeration cycle.
‘Split’ type heat pumps have separate heat collection and rejection units for each space known as ‘outdoor’ and ‘indoor’ units. The ’outdoor’ and ‘indoor’ units are specifically designed to be connected together during installation by refrigerant pipework to form a single functional system.
Variable Refrigerant Flow (VRF) heat pumps are systems specifically designed to automatically adjust the flow of refrigerant to each ‘indoor’ unit so that the heat delivered is matched to its demand. In particular, one of the ‘indoor’ units of a VRF system could be an air curtain.
1.2 Definitions
Air to Air Heat Pumps, Split, Multi-Split and VRF use an electrically operated refrigeration system to transfer heat from air outside a building to the air inside it. They can be used to provide space heating in a wide range of buildings, and some products also are able to provide cooling by reversing the refrigeration flows around the product (these products are also known as reversible ‘air-cooled’ air conditioning units).
Split, multi-split and VRF heat pumps are available with a wide range of efficiencies. The Energy Technology List (ETL) Scheme aims to encourage the purchase of higher efficiency products.
The ETL Scheme covers three categories of products:
1. Single split (non-VRF) heat pumps that consist of one ‘outdoor’ unit and one ‘indoor’ unit.
2. Multi-split (non-VRF) heat pumps that consist of one ‘outdoor’ unit connected to two or more ‘indoor’ units using either individual refrigerant circuits (with the indoor units individually controlled) or using a common refrigerant circuit with the indoor units controlled as one.
3. VRF heat pumps that consist of one ‘outdoor’ unit connected to one or more ‘indoor’ units using a common refrigerant circuit with the indoor units individually controlled.
A heat pump driven air curtain unit for VRF heat pumps may replace one or more ‘indoor’ heat pump units within an ETL eligible VRF heat pump.
Systems with cascade refrigerant/other-medium (e.g. water) heat distribution shall be tested using same methodology as other VRF systems, taking into account all additional energy used in supplementary medium loops, such as circulation pumps’ consumption. The supplementary energy consumption shall be measured at the relevant part load conditions for the unit defined in BS EN 14825:2018; and included in the effective power input that is used to calculate SCOPon (for heating efficiency), and SEERon (for cooling efficiency).
1.3 Requirements
1.3.1 Eligibility requirements
Eligible air to air heat pumps, split, multi-split and VRF shall comply with the requirements as set out below. The individual products do not need to be named on the ETL.
To be eligible, products shall:
- Consist of an ‘outdoor’ unit and one or more ‘indoor’ units that are:
- Factory–built sub-assemblies.
- Supplied as a matched set of units.
- Designed to be connected together during installation.
- Incorporate an electrically driven refrigeration system that uses a refrigerant which has a Global Warming Potential (GWP) of ≤ 750.
- Be designed for, and include fittings for, permanent installation.
- Have an appropriate Conformity Assessment mark.
To be eligible, heat pump driven air curtain ‘indoor’ units for multi-split heat pump products shall also:
- Be specifically designed to be fitted above a doorway or similar opening.
- Be designed to use electrical air heaters (where fitted) only during defrosting or heat pump failure.
1.3.2 Performance requirements
Eligible products must meet the performance criteria set out in Table 1.1 for:
- Seasonal Space Heating Energy Efficiency (ηs,h) as defined by Ecodesign Commission Regulation (EU) 2016/2281.
- Seasonal Space Cooling Energy Efficiency (ηs,c) as defined by Ecodesign Commission Regulation (EU) 2016/2281.
Products with a rated cooling capacity less than, or equal to, (≤) 12kW shall meet the performance criteria set out in Table 1.1 for:
- Seasonal Coefficient of Performance (SCOP) as defined by Ecodesign Commission Regulation (EU) 206/2012, across the range of connected capacities.
- Seasonal Energy Efficiency Ratio (SEER) as defined by Ecodesign Commission Regulation (EU) 206/2012 across the range of connected capacities.
Table 1.1 Performance requirements for air to air heat pumps, split, multi-split and VRF
|
Rated Cooling Capacity |
>12 kW |
≤12 kW |
|||
|
Product Category |
Heating mode (ηs,h) |
Cooling mode (ηs,c) |
Heating mode (SCOP) |
Cooling mode (SEER) |
|
| 1 | Single split (non-VRF) heat pumps | ≥157% | ≥230% | ||
| 2 | Multi-split (non-VRF) heat pumps | ≥185% | ≥270% | 4.30 | 6.60 |
| 3 | VRF heat pumps | ≥161% | ≥250% | ||
“≥” means “greater than or equal to”
In addition, eligible heat pump driven air curtain ‘indoor’ units for multi-split heat pump products shall have an outlet air velocity uniformity (uACU), as defined in Section 5.4.4 of BS ISO 27327-1: 2009, greater than or equal to 70% over the range of doorway/opening heights that they are designed to be fitted above.
1.3.3 Information requirements
Supplier shall report the following parameters for each model, which will be published on the ETL Product Search:
- Whether the model has ‘smart features’. Specifically, this includes the capability to provide information on whether the products are ‘smart ready’ without the replacement or addition of any hardware, which includes the following one or more options:
- Demand Side Response Ready
- Date Collection Ready, which includes:
- Storing data on the heat pump or a remote device.
- The ability to store data for each calendar year as a value per day, per month or per year.
- The following real time value parameters: electricity energy consumption (kWh); heat delivered (kWh); energy efficiency performance; operating times (days, hrs); number of on/off cycles.
- The SCOP and SEER for products with an efficiency performance presented in: ηs,h & ηs,c
- The ηs,h & ηs,c for products with an efficiency performance presented in: SCOP and SEER.
1.4 Measurement and Calculations
1.4.1 Energy efficiency metrics
Seasonal energy efficiency metrics are used, and should be measured for the ‘Average’ heating season, as defined in Ecodesign Commission Regulation (EU) 813/2013 and the harmonised standard BS EN 14825:2018.
Seasonal Coefficient Of Performance (SCOP) – overall coefficient of performance of a heat pump using electricity, representative of the heating season, calculated as the reference annual heating demand divided by annual energy consumption for heating, as defined by BS EN 14825:2018.
Seasonal Energy Efficiency Ratio (SEER) – ratio of the total cooling capacity to the effective power input of the unit, as defined by BS EN 14825:2018.
Seasonal Space Heating Energy Efficiency (ηs,h) – ratio between the space heating demand for reference heating season, supplied by a space heater and the annual primary energy consumption required to meet this demand, as defined by BS EN 14825:2018.
Seasonal Space Cooling Energy Efficiency (ηs,c) – ratio between the space cooling demand for reference cooling season supplied and annual primary energy consumption required to meet that demand, as defined by BS EN 14825:2018.
In case of any changes regarding the value of CC in relevant regulations or test reporting procedures, performance indicators will be calculated using following equations:
(1) ηs,h= SCOP/CC -F1
(2) ηs,c= SEER/CC -F1
Primary energy consumption for electricity usage is obtained using Conversion Coefficient (CC), known also as Primary Energy Factor, equal to 2.5, as defined by BS EN 14825:2018.
Correction factor (F1) is a correction that accounts for a negative contribution to the seasonal space heating energy efficiency of heaters due to adjusted contributions of temperature controls, equal to 3 % (BS EN 14825:2018).
Reference heating season, also called climate - set of operating conditions describing per bin the combination of outdoor temperatures and the number of hours these temperatures occur for heating for which the unit is declared fit for purpose. There are three reference heating seasons: “A” average, “C” colder and “W” warmer. UK is located in two reference zones: A and W, but for the ETL purposes “A” for average is to be used.
Outlet air velocity uniformity (uACU) - a percentage calculated from the average air curtain core velocity and velocity’s standard deviation, as defined by BS EN 27327-1:2009
1.4.2 Test Requirements
No additional testing requirements beyond the measurement standard below.
1.4.3 Measurement standards
Performance data for units with cooling capacity greater than 12 kW, and all non-VRF products should be obtained in accordance with requirements of Commission Regulation (EU) No 2016/2281 Annex III, and the harmonised standard BS EN 14825:2018.
Table 1.2 Measurement conditions for air to air split, multi-split and VRF heat pumps >12kW
|
|
Product Category |
Heating mode (ηs,h) |
Cooling mode (ηs,c) |
|
1. |
Single split (non VRF) heat pumps |
Commission Regulation (EU) No 2016/2281 Annex III, tables 21, 26, average climate conditions Rated Capacity (kW): Commission Regulation (EU) No 2016/2281 Annex III, Table 16 |
Commission Regulation (EU) No 2016/2281 Annex III, tables 21, 27, average climate conditions, Rated Capacity (kW): Commission Regulation (EU) No 2016/2281 Annex III, Table 16 |
|
2. |
Multi-split (non VRF) heat pumps |
Commission Regulation (EU) No 2016/2281 Annex III, tables 21, 26, average climate conditions Rated Capacity (kW): Commission Regulation (EU) No 2016/2281 Annex III, Table 16 |
Commission Regulation (EU) No 2016/2281 Annex III, tables 21, 27, average climate conditions Rated Capacity (kW): Commission Regulation (EU) No 2016/2281 Annex III, Table 16 |
|
3. |
VRF heat pumps |
Commission Regulation (EU) No 2016/2281 Annex III, tables 21, 26, average climate conditions Rated Capacity (kW): Commission Regulation (EU) No 2016/2281 Annex III, Table 16 |
Commission Regulation (EU) No 2016/2281 Annex III, tables 21, 27, average climate conditions Rated Capacity (kW): Commission Regulation (EU) No 2016/2281 Annex III, Table 16 |
Performance data for non-VRF products with a cooling capacity less than or equal to 12kW should be determined following the requirements of Commission Regulation (EU) No 206/2012 Annex II, and the harmonised standard BS EN 14825:2018.
Table 1.3 Measurement conditions for air to air heat pumps split, multi-split and VRF <12kW
|
|
Product Category |
Heating mode (SCOP) |
Cooling mode (SEER) |
|
1. |
Single, Multi-Split and VRF heat pumps |
Commission Regulation (EU) No 206/2012 Annex II, tables 1, 2, 3, average climate conditions | Commission Regulation (EU) No 206/2012 Annex II, tables 1, 2, 3 |
Please note that performance data obtained in accordance with the procedures and standard and conditions laid down in BS EN 14825:2016 will be accepted as an alternative to testing in accordance with BS EN 14825: 2018 until further notice.
1.4.3.1 Calculated results
Where results are determined by calculation then this should be on the basis of design and/or extrapolation from other combinations of indoor and outdoor units. In this case, details of such calculations and/or extrapolations, and of tests to verify the accuracy of the calculations undertaken (including details of the mathematical model for calculating performance of such combinations, and of measurements taken to verify this model) shall be made available. Tests undertaken to verify the accuracy of the calculations must be carried out in accordance with the test procedures described above.
1.4.4 Rounding
For the avoidance of doubt test data should be presented to zero decimal places for percentage points in ηs,h and ηs,c values and to 2 decimal places for SEER and SCOP indicators. As an example, a 20kW air source, single split (non-VRF) heat pump product with a heating mode ηs,h of 156.4% would be deemed to be a fail.
1.5 Verification for ETL Listing
Any of the following testing routes may be used to demonstrate the conformity of products against the requirements:
- In-house testing – Self-certified
- In-house testing – Self-tested and verified or cross-checked by an independent body
- Witnessed testing
- Independent testing
- Representative testing (see clause 1.5.1)
Further information regarding the first three routes can be found in the ETL Testing Framework.
1.5.1 Representative Testing
Where applications are being made for a range of products that are variants of the same basic design, test data may be submitted for a representative model, provided that all variants, i.e. models, share the following characteristic features:
- Use the same refrigerant
- Have the same compressor type (i.e. manufacturer, line of models), which should imply:
○ same method of compression (e.g. reciprocating or scroll) and
○ same type of enclosure (e.g. hermetic or semi-hermetic)
- Use the same defrosting method (e.g. hot gas defrost)
- Fit within the same product category (i.e. are all low-temperature air to water heat pumps, or are all non-low-temperature air to water heat pumps.
The representative models may be selected by dividing the range of products into groups of models with similar design characteristics. The performance of each model shall be predicted using a validated mathematical model. At least one model in each group shall be tested for validation purposes. A report documenting performed model calculations, showing all significant calculation steps, shall be submitted with the application.
It should be noted that:
- If a manufacturer voluntarily removes the representative model from the ETL then other products linked with that representative model may or may not be permitted to remain on the ETL.
- If any product submitted under these representative model rules is later found not to meet the performance criteria when independently tested, then all products based on the same representative model will be removed from the ETL.
1.6 Conformity testing
Products listed on the ETL may be subject to the scheme’s conformity testing programme in order to ensure listed models continue to meet the ETL requirements.
1.7 Review
1.7.1 Indicative review date
The next technical review is scheduled for 2025-26.
1.7.2 Illustrative future direction of the requirements
Future changes to the specification may include:
- Increasing the performance thresholds for ηsh, ηsc and/or SCOP, SEER.
- Updating the product eligibility and functionality requirements as per market demand and any UK or EU regulatory changes.
- The possibility of ‘smart features’ becoming an eligibility requirement for listed Air-to-air heat pumps.
- The possibility of updating the product eligibility requirements to encompass embodied lifetime carbon of heat pumps. Introducing a maximum value (measured in tonnes/ CO2) for the lifetime carbon of a heat pump.