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 Controls 6.53 Mechanical ventilation systems should have all of the following. a. The systems should be subdivided into separate control zones for areas of the building for which any of the following are significantly different. i. Solar exposure. ii. Pattern of use. iii. Type of use. b. For each control zone it should be possible to control all of the following (independent of other control zones). i. Timing ii. Where appropriate, temperature. iii. Where appropriate, ventilation rate. iv. Where appropriate, air recirculation rate. c. Central plant should operate only when the zone systems require it. The default condition should be off. 6.54 System controls should be wired so that when there is no demand for space heating or hot water, the heating appliance, if appropriate, and pump are switched off. 6.55 Central mechanical ventilation systems should have both of the following. a. Time control at room level. b. On/off time control at air handler level. 6.56 Heat exchangers should have both of the following. a. Defrost control to protect the heat exchanger. b. Control to ensure that heat recovery can be stopped, modulated or bypassed during periods when heat recovery is undesirable. Supply temperature control should be provided via a variable set point with outdoor temperature compensation. 6.57 Local and zonal systems should have on/off air flow control at room level. Heat recovery 6.58 Ventilation systems that provide supply and extract ventilation should be fitted with a heat recovery system where technically feasible. Lighting 6.59 Any fixed lighting should achieve levels of illumination appropriate to the activity in the space. Spaces should not be over-illuminated. Lighting should be designed based on CIBSE’s SLL Lighting Handbook or an equivalent design guide. NOTE: For smaller spaces where total lighting power is likely to be low (toilets, store rooms etc.) there is no expectation that lighting calculations should be produced. 52 Approved Document L Volume 2, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N