Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings

L1(b), L2 O N L I N E V E R S I O N b. For each control zone and for each terminal unit, it should be possible to control both of the following (independent of other control zones). i. Timing. ii. Temperature. c. If both heating and cooling are provided in the same space, the controls should prevent them operating simultaneously. d. Multiple cooling units should be provided with controls that ensure that the combined plant operates in its most efficient modes. Central plant should operate only when the zone systems require it. The default condition should be off. e. Controls for comfort cooling systems should meet BS EN 15232 Band C. f. Controls should meet the requirements for thermostatic room controls in paragraphs 5.14 to 5.16. Calculating the seasonal energy efficiency ratio 6.36 The value of the seasonal energy efficiency ratio (SEER) and the seasonal coefficient of performance (SCOP) should be determined using BS EN 14825 with average climate data; in conjunction with the Ecodesign Commission Regulation No. 2016/2281. The SEER of the cooling unit is given by equation 6.7. SEER = a(EER ) + b(EER ) + c(EER ) + d(EER ) equation 6.7 100% 75% 50% 25% Where: EER is the EER measured at the load conditions of 100%, 75%, 50% and 25% at the operating x conditions detailed for the part load energy efficiency ratio. a, b, c and d are the load profile weighting factors relevant to the proposed application. The load profile weighting factors can be taken from either of the following. a. Table 6.7, if appropriate. b. A detailed simulation or prediction of the load profile of the building. The calculation should include the desired indoor condition as well as the ambient loads in which the system will work. Table 6.7 S tandard cooling load factors for office accommodation a b c d 0.03 0.33 0.41 0.23 6.37 For cooling units for which there is no part load data, the SEER is the full load EER. For applications where the load profile is not known but there is some data on chiller part load EER, the following apply. a. For chillers where the full and half load (50%) EERs are known: the SEER is the average of the full load and half load EERs. b. For chillers with four points of part load EER: the SEER is calculated using equation 6.7 with each EER weighted equally. c. If the chiller used does not have data for four steps of load: the weights are apportioned appropriately. 48 Approved Document L Volume 2, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N