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

O N L I N E V E R S I O N L1(b), L2 6.38 For plants with multiple chillers, a plant seasonal energy efficiency ratio (SEER) should be calculated based on the sum of the energy consumption of all the operating chillers. All the following factors should be included. a. Degree of oversizing of the total installed capacity. b. Sizes of individual chillers. c. EERs of individual chillers in operating conditions. d. Control mode used, e.g. parallel, sequential, dedicated low load unit. e. Load profile of the proposed building. f. Building location (which determines ambient conditions). 6.39 For systems that have the ability to use free cooling or heat recovery, the SEER should be derived for the specific application, including free cooling or heat recovery elements. For variable refrigerant flow (VRF) systems, any calculations must include indoor and outdoor conditions, the power input from controls, and indoor units. 6.40 For absorption chillers used in conjunction with on-site CHP or a district heat network or community heating system, the CO emissions and primary energy should be calculated in the 2 same way as when using CHP for heating. The control system should ensure as far as possible that heat from boilers is not used to supply the absorption chiller. The minimum full load EER of the absorption chillers should be no worse than 0.7. 6.41 For district cooling schemes, the CO and primary energy content of the cooling energy supplied 2 should be calculated. This value should be used to calculate the building emission rate and primary energy rate. Heating and cooling system circulators and water pumps 6.42 On variable volume systems, variable speed glandless circulators should be used. 6.43 If a water pump is used on a closed loop circuit and the motor is rated at more than 750W, then it should be fitted with or controlled by an appropriate variable speed controller on any variable volume system. Heat pumps 6.44 Air-to-air heat pumps with an output of 12kW or less should have either of the following. a. A seasonal coefficient of performance (SCOP) rating for the median temperature range in BS EN 14825 of at least D. b. A coefficient of performance (COP) that is not less than the value in Table 6.8. 49 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N