Individual comfort - keeping you snug and saving energy too.

We are into the season of chilly evenings and this story caught my eye, even though it is from California and is as much about cooling as heating - the 'Personal Comfort System'. When I was working in an open plan office there was always someone complaining they were too hot or too cold. Whether the air circulated through vents in the floor or ceiling, someone would get cold legs or a cold neck. The new system gives you a heated pad for your feet, and in your chair (presumably your back), and cooling fans at strategic places too. You can configure it just how you like it.


This was designed by researchers at the University of California, Berkeley, Centre for the Built Environment (CBE) with funding from the California Energy Commission. The basic PCS sounds pretty straightforward to me but the whole project has $1.6 million to spend so they are also experimenting with gee-whiz interfaces to phone apps, weather forecasts, temperature sensors and so on.

CBE estimates that the system can save 39 percent on gas for heating and  30 percent on electricity for ventilation and air conditioning in typical California commercial office spaces. It uses typically 40W for heating though the maximum power is 160W. 40W for an 8 hour day is only 0.3 kWh: about 4-5p at current domestic electricity prices

You can roll your own basic PCS using snug heated foot warmers and electric blankets or heating pads. The PCS concept is not just for the office - it can apply just as well to an arm chair as a desk chair. You can get pads for pets too, especially loved by cats - search for 'pet heating pads'. Devices are usually rated at 20 - 100 W but will use less then this at lower temperature settings. However, even 100 W for 10 hours is only 1 kWh costing 12-14p. This is a great deal cheaper than heating the whole house.

On the other hand beware USB powered heating gizmos. The USB supplies at most 2.5 W which isn't going to make much difference.   You can even get a heated mouse mat - so how do you keep your other hand warm?

One caveat - when we discussed these types of systems in our Transition Cambridge Energy group meetings it was pointed out that vulnerable people need warmth in the whole house, not just their arm chair. For example, I have an elderly aunt who had an accident at home and was found lying on the floor unconscious 8 hours later. If the house was not warm she could have died of hypothermia.

Personally, my favourite warming technique for the chilly evenings is to snuggle up to my beloved under a blanket on the sofa.