We’ve built an entire house in a lab to dispel common energy efficiency myths
EconoTimes, March 19, 2016. Image credit: University of Salford Press Office
A common piece of advice is to turn your thermostat to 21°C to ensure an energy efficient and comfortable home. However, work by my colleagues and I found older thermostats can easily vary by up to 2°C, meaning we could actually be heating our homes to anything between 19°C and 23°C. If we consider the Energy Savings Trust’s advice that reducing home temperature by 1°C could save 10% on heating bills, then this discrepancy has implications.
To investigate these gaps, paradoxes and myths, colleagues and I established the Salford Energy House. Essentially it’s an entire terraced house, built from brick to traditional British housing standards, but constructed within a climate controlled chamber. This allows us to manipulate the weather to be anything from -12ºC to +30ºC or as rainy and windy as we like.
Given we know exactly how the house was built, how it is “used” (by our researchers), and the “weather” it is exposed to, we can get a very good idea of how efficient it is. When we add curtains, better thermostats or other improvements, we can compare results with those from the original, unimproved house and try to find the difference. Our tests are extensive, detailed and give us data that would be impossible in the field – no actual homeowner would want nearly 300 sensors attached to their house.
And what did we find? We added living room thermostats and thermostatic radiator valves and established energy savings of over 40% when compared to a property with no controls. We identified that curtains reduce heat transfer through the windows by about 30% when closed. When we retrofitted the whole house with floor insulation, solid wall insulation, loft insulation and new glazing, the annual heating costs were reduced by a huge 63%.