What’s a good room temperature?

If you are “heating the air”, then you need to think about your target room temperature.

What makes for an acceptable room temperature has crept up over the years. Between 1980 and 2013, it was illegal in the UK to heat public spaces to above 19C unless there was good reason, like that they were used by the very young or older adults. The law was created in response to worries about the UK’s energy supply. The law was much ignored and only ever used by employers to respond to workers who asked them to turn the heating up. The restriction was removed when the crisis was over as part of a drive to remove “red tape”.

Most thermostats and thermostatic radiator valves go to 26C. If you have thermostats that the public can reach, you are likely to find them set that way. The Health and Safety Executive recommends never heating above 24C because this can be dangerous for people with heart conditions. The World Health Organisation and UK policy experts would like to see 18C become the norm for heating as that’s perfect for general health, but a big step down from what many Westerners are now used to. The most believable of the possible UK climate policy models requires average room temperature to be set to 16C.

Think “higher” or “lower”, not numbers

Although policies have to specify numbers, you shouldn’t take the actual numbers on a thermostat too seriously.
Partly this is because they can only measure air temperature - people might need a higher air temperature when the walls are very cold, for instance. Partly it is because it can be hard to find a location for the thermostat that will make it read the same air temperature as the building’s users will experience. The thermostat might do something useful but 19C on the dial could be a different temperature for the people elsewhere in the room. It’s best to set a thermostat to whatever position makes people comfortable on average, in your experience of the space, rather than taking the temperature reading seriously.

Unfortunately, most building users will automatically reset a thermostat so it reads the same as whatever temperature they set the thermostat to at home. Modern thermostats and programmable room thermostats with digital displays usually have an offset feature that can be used to adjust for the difference between what the thermostat reads and what the building users feel. For instance, if the user sets it to 19C, an offset of -3C would use 16C in its control of the room. This can be a very useful feature in community buildings.

Your organisation should have a policy in place setting target temperatures and have the technical or social controls to enforce the policy. Keep in mind that the standards assume space heating. If you are heating the people, you don’t need a target room temperature, and if you are mixing the two approaches, your target temperature can be lower.