There are a number of heat pump types which may or may not have relevant Ecodesign data & declarations, or accredited EN14825 or EN16147 data. Generally speaking, the standard guidance applies to these systems with additional information provided as follows.
Air to air heat pumps heat air rather than wet heating system emitters such as radiators and underfloor heating. These systems usually source their heat from external air and do not provide DHW, However, if an air-to-air heat pump is providing DHW, then it is entered separately in the water heating section as an air-to-water heat pump.
DEAP can accept Ecodesign based or HARP based data for these devices and applies an efficiency adjustment factor of 1.
EAHPs are considered as a mechanical extract ventilation and heat pump unit in DEAP. Where an EAHP is in scope of Ecodesign Regulations for heat pumps, follow the guidance here. The flow rate for the EAHP is entered in the DEAP ventilation section as detailed here in the ventilation section.
For EAHP units not in scope of Ecodesign/Labelling directives, please contact the BER helpdesk for guidance.
Double duct air conditioners and heat recovery systems incorporating heat pump functionality (referred to hereafter as double duct air conditioners) include both “passive” heat recovery, through a heat exchanger and “active” heat recovery, through a heat pump. This type of appliance is accounted for in DEAP as follows. The double duct air conditioner is broken down into its mechanical ventilation heat recovery (MVHR) and heat pump components:
Table 4.24 – Test Conditions
| Extract air inlet dry bulb (wet bulb) Temperature (°C) | Outdoor air inlet dry bulb (wet bulb) Temperature (°C) |
|---|---|
| 20 (12) | 7 (6) |
| 20 (12) | 2 (1) |
| 20 (12) | -7 (-8) |
The performance of the heat pump from EN 13141-7 must exclude heat recovery performance. Where the performance of the unit combines the heat recovery and heat pump performance, the heat pump performance must be separated based on the following methodology for each of the test points.
Output of heat pump = 1.2 x air flow rate (l/s) x (air temp off – air temp on),
where:
Air temp on = % x (extract air temp – outside air temp) + outside air temp
A similar type of appliance, including only “active” heat recovery mode (through a heat pump), is defined as “Exhaust Air to Air heat pump”. This type of heat pump can be entered in DEAP using the Heat Pump Calculator 2020.
Thermodynamic solar/heat pump systems are treated the same as air/water heat pumps but use a flat plate solar collector (usually unglazed) instead of an outdoor fan as a means of collecting heat. These systems are treated as follows in DEAP:
The DEAP methodology allows for heat pumps in group heating schemes by determining the proportion of the total group scheme occupied by the dwelling being assessed. As detailed elsewhere, where a heat pump is present, the group heating heat pump calculator and methodology should be completed.
The following heat pumps are catered for in the Heat Pump Calculator 2020:
Note on multiple heat pumps: When there are two or more identical heat pumps serving a single dwelling, both heating the same circuit in parallel1, they may be entered in DEAP as one heat pump with equivalent heat output. To account for the equivalent heat output, the capacities (Pdh) at each test point needs to be multiplied by the number of heat pumps. The declared COP for each test point applies as it is (this must not be multiplied). Multiple heat pumps may not be entered as a single heat pump in any of the following cases:
In these cases, they need to be entered according to the 2020 DEAP heat pump methodology and calculator.
1 - Heat pumps in parallel have common outlet and inlet temperatures, as shown in the diagram: (Image needed)
The following steps are used for the treatment of EAHPs in DEAP calculation procedure for heat pumps that are not compliant with the Ecodesign and Energy Labelling Directives when applying an “uplift” to the Seasonal Performance Factor (i.e. heat pumps installed prior to September 2015 and without:
1.DEAP Ventilation Section:
Select the “Exhaust air heat pump” option. Provided the inlet air vents in the living spaces are each less than 3500 mm2, a nil entry can be made in respect of this aspect of ventilation.
Apply a specific fan power (SFP) of 0.26 W/l/s as default. This is a weighted figure based on a zero figure during the heating season and a figure of 0.8 W/l/s for summertime operation. For seasonal fan power, use an alternative figure as per the SAP PCDB as referenced under Section b) above.
2. DEAP Hot Water Section:
As per heat pump tool Select a heat storage tank with a standing loss that reflects the insulation specification of this component of the system. Where the EAHP is being cited as the main domestic hot water heating source, and is equipped with a direct auxiliary heating element, then the procedure set out in DEAP Appendix G (Equation G1) assuming a 50:50 allocation between the heat pump and direct electricity must be applied to the determination of efficiency.
3. DEAP Energy Requirements Section:
The efficiency (CoP or seasonal performance factor, SPF) to be used is either the default figure offered by DEAP Table 4a, or the average of the CoPs determined by independent testing to the European Standard EN 14511-2 by an accredited laboratory, for the three sets of conditions shown in the following table, i.e. the average of the efficiencies at:
Image needed
4. System design info: System sizing check:
It is also recommended that a design heat loss and heat demand calculation be carried out for the dwelling based on a standard indoor – outdoor temperature difference, plus domestic hot water demand, with a check against the rated output of the EAHP under such conditions. It may in this context be appropriate to provide for a suitable plant capacity margin to enable heating up from cold following an extended period of absence.
5. Renewables Compliance
When using DEAP to evaluate a dwelling's compliance with the renewables requirement described under TGD L, the same method as outlined above is used with an alteration to the SPF in step (3). The three test points which should be used for renewables compliance checking for an Exhaust Air Heat Pump are A2/W35; A7/W35 and A7/W45.
The COPs from EN14511 at these test points are averaged to obtain the SPF when evaluating the renewables compliance of the dwelling. This SPF is in turn entered in DEAP to check if renewables compliance as per TGD L is achieved following steps 1-4 above. Where the BER Assessor carries out the renewables compliance check (for example on a new dwelling) they should inform their client regarding the result of the compliance check, and retain records relating to the compliance check with the assessment records. The BER is published using the SPF from step (3) above including the A20/W45 test point rather than the A2/W35 test point.