Professor David Johnston (PI), Professor Chris Gorse, Professor Jiamei Deng, Dr David Glew, Dr Adam Hardy

Project description

In winter, dwellings experience a time lag between turning on their central heating system and reaching their desired internal set point temperature. The speed at which the central heating can achieve the occupant’s desired internal set point temperature is determined by many factors including; the thermal efficiency of the building fabric, the responsiveness of the building fabric, the efficiency and capacity of the boiler, the efficiency of the distribution system, the type and position of the heat emitters, the external temperature and, of course, the actual internal set point temperature selected by the occupant.

This project will attempt to characterise building thermal response and quantify the amount of time it takes for dwellings to heat up to the desired internal set point temperature during winter, and thus the amount of time in which they spend in thermal discomfort.  The time taken can be defined as a ‘heat-up time lag’. Characterisation of building thermal response, along with analysis and quantification of the ‘heat-up time lag’, will also enable the identification of those dwellings that are most vulnerable to extreme weather events.

Therefore, this project is important for a number of policy related reasons. For instance, when considering fuel poverty and cold related illnesses in homes; when considering the impact of extreme weather events and future climate scenarios on the housing stock; determining the potential impact on thermal comfort of switching to low temperature heat emitters and technologies such as an air source heat pump, as part of a wider decarbonisation strategy; evaluating the scale of the modelling gap in SAP and RdSAP, which assumes the instantaneous heat-up (no heat-up time lag) of homes; targeting homes for domestic retrofits; evaluating the impact of energy efficiency policy on winter time comfort, and even evaluating the improved thermal comfort resulting from policy that specifies minimum EPC bands.