EN 15316-4-2-2017 pdf download.Energy performance of buildings – Method for calculation of system energy requirements and system efficiencies – Part 4-2: Space heating generation systems, heat pump systems, Module M3-8-2, M8-8-2.
Qhw;grn;in is the ambient heat energy used as heat source of the heat pump;
fgrn;jux;I.rvJ is the recovered fraction of heat energy from the auxiliaries (if not included in the
COP);
is the auxiliary energy input to operate the generation subsystem.
In case of electrically-driven heat pumps, the term EHWgrIIn is the electrical energy input necessary for the heat pump system to cover the energy requirement of the distribution subsystem. It comprises the electrical energy input to the heat pump system and possibly installed back-up heaters.
According to the EN 14511 series, EHW;nin also includes the fractions of the auxiliary energies included in the COP, i.e. the energy for control and safety devices during operation, the proportional energy input for pumps and fans to ensure the transport of the heat transfer media inside the unit as well as eventually energy for defrost operation and additional heating devices for the oil supply of the compressor.
Thus, WHW;g.IUX only comprises the fractions not included in the COP standard testing. fgrniisd describes the fraction of auxiliary energy, which is recovered as thermal energy. e.g. for pumps where a fraction of the auxiliary energy is directly transferred to the heat transfer medium as thermal energy. This fraction is already contained in the COP according to the EN 14511 series for electrically-driven heat pumps, SOfnux;Id = 0.
— For total heat losses Q4w;genIs(ot, the heat losses of the heat pump over the envelope are neglected unless heat loss values of the heat pump are known, e.g. given in a national Annex. For systems with integrated or external heating buffer or DHW hot water storage, generation subsystem losses in form of storage heat losses and losses of the connecting circulation pipes to the storage are considered.
In case of the combustion engine-driven and absorption heat pumps:
— EHWgrnin describes the driving energy input to cover the heat requirement of the distribution subsystem for heating and domestic hot water. For combustion engine-driven heat pumps, this driving energy is fuel, e.g. as diesel or natural gas. For thermally-driven absorption heat pumps, fuel-driven burners, but also solar energy or waste heat can be the driving energy input.
— Qiiw:en;out the heat energy output of the generation equals the heat requirement of the distribution subsystem and contains all fractions of heat recovered from the engine or the flue gas of the engine, i.e. recovered heat from the engine in entirely considered within the system boundary of the generation subsystem.
— fgn;aox.Is;rvd gives the fraction of the auxiliary energy recovered as thermal energy and depends on the test method. The fractionf .1.,.vd = 0, if the recovered heat is already included in the COP.
Auxiliary energy is energy needed to operate the generation subsystem, e.g. the source pump or the control system of the generator.
For electrically-driven heat pumps thermal capacity and COP in this standard are calculated on the basis of results from product testing, according to the EN 14511 series, only the auxiliary energy not included in the test results, e.g. the power to overcome the external pressure drop and the power in stand-by operation, shall be considered in WHw;rn;aux.
For combustion- engine driven heat pump, the electrical energy necessary to operate the heat pump is not measured according to EN 12309-2. considers this energy use as a percentage of the energy input at full load” with the electrical energy necessary to operate the heat pump is measured according to EN 12309-4.
Auxiliary energy is accounted to the generation subsystem as long as no transport energy is transferred to the distribution subsystem. That means, in general the circulation pump is accounted to the distribution subsystem, unless a hydraulic decoupling exist. For a hydraulic decoupling between the generation and various distribution subsystems. e.g. by a heating buffer or domestic hot water storage in parallel configuration, the primary pump is accounted to the generation subsystem, as well.
In this case, the power to overcome the external pressure drop has to be taken into account. If no primary pump is considered, since there is no hydraulic decoupling between the generation and distribution subsystem, the COP-values have to be corrected for the internal pressure drop, which is included in the COP-values by the standard testing.
5.7 Recoverable, recovered and unrecoverable heat losses
The calculated losses are not necessarily lost. Parts of the losses are recoverable, and parts of these recoverable losses are actually recovered. The recovered losses are determined by the location of the generator and the utilization factor (gain/loss ratio, see EN ISO 13790).
Recoverable heat losses QK;,trbI are e.g. heat losses through the envelope of a generation subsystem, e.g. in form of storage losses when the storage is installed in the heated space. For a generation subsystem installed outside the heated space, however, the heat losses through the envelope of the generator are not recoverable.
Flue gas losses of fuel engine-driven heat pumps are considered not recoverable, since all recovered flue gas losses inside the generation subsystem limits are contained in the heat output QHW:In:DUt
Neglecting the thermal losses if below a certain percentage of the heating or cooling demand, can be introduce at a national level.
Neglecting the recovered and recoverable losses from auxiliary energy demand if below a certain percentage of the heating or cooling demand, can be introduce at a national level.
5.8 Calculation by zones.EN 15316-4-2-2017 pdf download.