Over the past 3 years, I have been researching the problem of how to keep people warm in our wide diversity of UK housing without wasting energy and keeping costs manageable. My studies have included conventional central heating, heat pumps and Infrared heating and, most recently, I sampled how warm 77 individuals in 61 different homes felt at particular moments in time over 30 winter days. The current air temperature in the room they were in was also recorded along with their recent activities.

The most striking findings from the studies are:

• there is wide variability in how warm individuals feel on a 7 point scale… even compared to other members of their household
• the current air temperature is not a significant factor (only accounting for 14% of this variance)
• people’s felt warmth varies at different times due to a complex and unpredictable combination of ‘in the moment’ physiological, physical, psychological, behavioural and contextual factors
• the different forms of heat: convection, conduction or radiation matters. Interestingly, 87% of the 71 houses studied had some form of hybrid heating that they used in addition to their main form of heating, e.g. log burners, agas, fan heaters or portable radiators.

Co-incidentally, our community hydro company, Talybont on Usk Energy, has funded an offer of 25 electrically heated throws to elderly members of our small rural community this winter if they are suffering from feeling cold. I have spent the past week delivering throws to folk who have requested them. Anecdotally, in line with my research studies, it’s proving a further example of the fact that warm air doesn’t actually heat us (until it reaches 37 degs!) but is important in reducing how quickly we lose bodily heat. In every home I’ve visited, the air has felt comfortably warm (20 degs plus) thanks to the central heating or heat pump being on but residents still feel uncomfortably chilly in their legs or back or shoulders and are often operating a portable electric bar or fan heater to supplement their central heating.

If people are sitting still for large stretches of time and are also elderly and frail, they can become cold and then need either vigorous exercise or a conductive or radiant heat source to warm their bodies directly. The good news is that electrically heated throws deliver a conductive effect quickly and effectively and do so by consuming only 160w – about 6 times less energy than an electric heater which is attempting to raise the air temperature. The heat level is also under each person’s direct control and studies have shown that people simply feel warmer if they know they are in control of the heat source – hence the temptation to turn up the thermostat even if that isn’t actually necessary or effective in raising their body heat.

Food for thought…

..