W4LP8 – The effect of internal wall insulation in solid wall dwellings on energy demand, thermal comfort and overheating

18th October 2015 Vicki Tink

The effect of internal wall insulation in solid wall dwellings on energy demand, thermal comfort and overheating

Vicki Tink, Loughborough University

Approximately 30% of the UK’s housing stock is comprised of older, solid wall buildings. These buildings have high heat loss, can be uncomfortable for occupants throughout the winter and require an above-average amount of energy to heat. Solid wall buildings can be made more energy efficient and winter thermal comfort can be improved by the installation of internal wall insulation (IWI). However, there are concerns that internal wall insulation could lead to overheating in the summer.

Through the course of this doctoral research Vicki had sole access to a unique facility comprised of a matched pair of solid wall semi-detached houses. The houses were characterised and monitored with both in their uninsulated state, then the left house of the pair was retrofitted with internal wall insulation and the process was repeated. Characterisation was a series of tests consisting of a co-heating test, U-value measurements, airtightness tests and an infra-red camera survey. Monitoring was the measurement of internal and external air temperatures, thermal comfort parameters (air temperature, mean radiant temperature, air speed, humidity), wall surface temperatures, gas and electricity consumption over periods of three weeks in winter and summer. The test schedule can be seen below:

The outcomes of this research will be empirical evidence into the debate over whether IWI is an appropriate retrofit strategy to reduce national building energy consumption and provide dwellings that are comfortable year-round.