Conservation of fuel and power: Approved Document L, Volume 1 — Dwellings

O N L I N E V E R S I O N L1(b), L2 6.35 Programmable room thermostats with an override feature should be provided for all direct electric zones of the electric underfloor heating system. Thermostats should have air and floor temperature sensing capabilities which may be used individually or in combination. Heat pump heating systems NOTE: For heat pumps that provide comfort cooling, guidance is also given in paragraphs 6.49 to 6.53. 6.36 Electrically driven air-to-air heat pumps with an output of 12kW or less should follow the Ecodesign Commission Regulation No. 2016/2281 for air heating products, cooling products, high temperature process chillers and fan coil units. 6.37 For other types of heat pump, not defined in paragraph 6.36, the coefficient of performance should be both of the following. a. For space heating, a minimum of 3.0. b. For heating domestic hot water, a minimum of 2.0. 6.38 The heat pump unit should include controls for all of the following, in addition to meeting the general requirements for heating and hot water systems in Section 5. a. To control water pump operation (internal and external, as appropriate). b. To control either of the following. i. For wet systems, water temperature. ii. For air systems, air temperature. c. For air-to-water and air-to-air units, to control outdoor fan operation. d. For air-to-water and air-to-air systems, to provide a defrost control for the external air-side heat exchanger. e. For air-to-air systems, to control secondary heating (if fitted). f. To protect against water flow failure. g. To protect against high water temperature. h. To protect against high refrigerant pressure. i. For air-to-water and air-to-air units, to protect against air flow failure. 6.39 The heat pump should have external controls that include both of the following. a. Weather compensation or internal temperature control. b. Timer or programmer for space heating. 6.40 For heat pump installations in which there are other heat sources available to the same building, each of these heat sources should be appropriately incorporated into a singular control system. 6.41 Heat pumps should be located and installed subject to the manufacturer’s guidance. In regard to air source heat pumps, this includes the consideration of factors that may adversely affect their performance, e.g. the avoidance of cold exhaust air recirculation and the removal of condensation from the outdoor coil during a defrost cycle. 6.42 Heat pumps should not be sited adjacent to sleeping areas, nor should they be located on materials that can readily transmit vibrations. Additionally, the location of external fans and heat pump compressors should be appropriately selected to minimise disturbance to neighbours, while remaining in compliance with planning requirements. Building Regulations 2010 Approved Document L Volume 1, 2021 edition 47 O N L I N E V E R S I O N