Where to put the monitor#
If you move a thermal monitor or other measuring device around your building, it’s easy to lose track of which readings are for which location. You can use this template to help you remember.
Ideally, you will get one or two weeks of data when it is relatively cold out in each of your big spaces, representative smaller spaces, and anywhere else that you think might be different or have a problem. Even better is a week or two in each season since that helps identify problems with solar gain or poor heating control. The more varied your diary and your user groups, the longer you need. It’s useful to just keep a monitor on permanently so you can spot suspicious changes from what’s normal quickly, but we aren’t really set up for that. Smart meters are better designed for this, they just won’t tell you where the waste is.
When you decide where to put the thermal monitor or data logger, it should be:
somewhere representative of what people will feel
not in a corner or anywhere else with poor airflow
not in direct sun or influenced by a heating source like a radiator
not very close to a very cold wall (for instance, external stone walls) or on a windowsill
not on a hot thing (like some light fittings)
preferably not close enough to an actual person to be influenced by their body heat
not where it will be hit by footballs, thrown around by children, and so on
if it relies on the wifi network, where the signal is strong enough
These are the same rules as for thermostats, and sometimes next to the thermostat is a good choice, although some of them can be very badly sited!
Wifi strength
If you aren’t sure whether the wifi is a problem, try the monitor right next to the router. Then you’ll be sure the signal is strong. If it’s working there, then the problem is likely to be the signal strength where you want to place it. The monitor flashes 10 times in a row when it makes a successful connection, but it can be hard to see this on some monitors.
In many spaces, you have to compromise on the location. That’s OK! Temperature and RH never tell the full story about thermal comfort in a space. You’ll still get to understand whether the heating is on at the right times and have an idea about warmer and colder that you can tally against your own experience of the building.
Blutak and adhesives
Blutak can mark many surfaces and tape can leave permanent marks on stonework. It’s not a good look.
In some spaces you may need to be inventive. You could:
hang it from a pillar by tying string around the sensor as if you were wrapping a gift and then using another piece of string to hang it - making a cradle so it won’t fall and hit anyone
balance it on a crossbeam above the centre of the space
tape or tie it under a piano or church altar
place it in a church pulpit - although sometimes they are terribly cold and draughty compared to where the congregation sits
In spaces without pillars where all the furniture moves, you just have to do what you can - sometimes a windowsill is the only option and you just have to keep its placement in mind. Air temperature is never the full story on thermal comfort anyway.
Tip
It can be hard to remember where you put the sensor unit - one easy way is to take a picture on your phone that shows the surrounding context. Then if you forget, you’ll know exactly where to look. We sometimes are able to loan groups a large set. In this case you’ll need to take pictures of each location and write down which number is in which one.