Water-proofing poised to cut energy use
Scientists at the University of Portsmouth investigating the effects of applying a silicone-based compound to a test house found that in wet conditions the amount of energy needed to heat the house was cut by almost a third
Scientists at the University of Portsmouth investigating the effects of applying a silicone-based compound to a test house found that in wet conditions the amount of energy needed to heat the house was cut by almost a third. This would cut the average heating bill on a semi-detached house with loft insulation and double glazing by over £100 per year.
The project was part of a government competition to find innovative solutions for improving the environmental performance of the UK's housing stock. Housing in the UK accounts for 27 per cent of carbon emissions and more than 80 per cent of the houses we will live in by 2050 have already been built.
The University of Portsmouth collaborated with Safeguard Europe Ltd, a UK-based company specialising in providing damp-proofing and waterproofing solutions for the construction industry. They received £20K funding from the Technology Strategy Board (TSB) to test Safeguard's waterproofing technology.
They built a small scale brick house and used a 40 watt light bulb as the heating source. They controlled the outside temperature and humidity and fixed the internal temperature at 20C. The energy consumption to maintain the internal temperature was measured before and after the application of the water proofing chemicals to the exterior walls of the test house.
With external temperatures of 0 C and 80 per cent humidity, energy consumption reduced by nine per cent. When the external temperature was increased to 10 C energy reduction dropped to five per cent. But a second experiment with 'rain' resulted in a 30 per cent reduction in energy consumption.
Dr Zhongyi Zhang from the University's Department of Mechanical and Design Engineering said: "Moisture increases the thermal conductivity of bricks and mortar. By keeping the brickwork dry we can significantly improve its insulation properties and there will be no cooling effects from water vaporisation. The concept is simple but effective and should work particularly well in the UK climate and north Europe."
Dr Eric Rirsch, Research and Development Manager at Safeguard said:
"It's a low-cost easily-applied system which is non-intrusive and can be carried out with the householder in residence. It doesn't alter the surface appearance so there is no impact on the aesthetics of the building and it can be used to treat a wide range of building materials making it ideal for the average home and for listed buildings and heritage conservation."