A field study of thermal comfort in low-income dwellings in England before and after energy efficient refurbishment

Abstract

This study investigates the effect of England's Warm Front energy efficient refurbishment scheme on winter thermal comfort in low-income dwellings. The analysis is based on an extensive survey of some 2500 dwellings selected from five major urban areas in England over the winters of 2001/02 and 2002/03. The surveys were carried out either before or after the introduction of retrofit insulation and energy efficient heating system. Self-reported thermal comfort (measured on a seven-point scale) and indoor temperature in the living room and in the main bedroom were recorded twice daily at 8 a.m. and 7 p.m. over 11 consecutive days. Results show that Warm Front was effective in increasing the mean indoor temperature from 17.1 °C to 19.0 °C leading to an increase in the proportion of households feeling thermally ‘comfortable’ or warmer from 36.4% to 78.7%. Warm Front also led to a slight increase in the whole house neutral temperature, i.e. the temperature at which most residents feel thermal neutrality, from 18.9 °C to 19.1 °C mainly from reduced clothing level associated with greater energy efficiency. Predicted Mean Vote, which is the standard thermal comfort model in ISO Standard 7730 predicted a higher neutral temperature of 20.4 °C compared to 18.9 °C found to be ideal among the average Warm Front households.