Temperature and relative humidity readings#
Regular temperature readings are very useful for understanding where you are wasting energy on heating. Monitoring often indicates that a small change in practice or a small investment in different heating controls will save enough money to be worth the bother. In buildings that are slow to warm up and not used all the time, it’s common to discover a quarter of the heating is wasted, and we have sometimes found much bigger problems, like a church hall that had accidentally been heated 24/7 for years. Monitoring will also help you understand and handle user complaints and know when maintenance is required.
Your heating controls might already log room temperature for you.
Relative humidity readings are also useful if you have any concerns about damp or dryness in your building. That might be because you want to be sure the conditions are right for people, or it might be because you want to safeguard the building or its contents. This is less important than recording temperature because if it’s too damp or too dry for the people in the building, it should be obvious. However, if you are a church with a pipe organ or other sensitive furnishings, or a building with unfrequented spaces that you think might be damp, it’s useful to have a device capable of monitoring relative humidity (RH) so you can use it for this some of the time. It’s difficult to measure relative humidity accurately so you should treat the readings as approximate.
Venues without wifi
There are USB sticks that save the data for you. This one comes with free Windows sofware. There may be cheaper options but we haven’t tried them.
We are only aware of one suitable model, the Thermopro TP357s, but there are probably others. You use an app to retrieve the data over a Bluetooth connection.
The Thermopro is intended to be used for live monitoring of, say, a nursery at home, but it stores some data on the sensor unit itself to cover when the phone is out of range. Thermopro says that if the battery dies, the data collected before that will still be found on the unit if you insert a new battery. You can use the same phone with more than one Thermopro.Since February 2024, the sensor unit allows the data to be exported and emailed to someone. Amazon is out of the old stock but we’re less sure about other vendors. If you want to avoid Amazon, ask the Thermopro chat advisor about your options. We know they’re available on Ali Express, but we aren’t sure where else.
Venues with wifi
You can use the options above, but it is very convenient to have one that can use your building’s wifi to make the data appear on a website. Lascar does one like this, but it’s relatively expensive.
We are always on the look out for new options coming on the market, but they usually assume you want the data instantly, so they either require an electrical socket or assume an additional device that does. This doesn’t work very well in public spaces. They just get unplugged.
Meanwhile, we have electronics volunteers make up suitable monitors from parts. Although there is an option to use them without wifi, it’s more difficult than using the Thermopro, so we now prioritize building for buildings with wifi.
Setting them up with your wifi details is a pain but we now ship them with your wifi details pre-loaded. It costs us about £10 to make and post them out, and at the moment we’re paying around £300 a year for service that gets the data to the internet. We’re OK for now, but we may need to find a way to cover these costs.
Tip
Sometimes commercial options are called “data loggers”. We just say “thermal monitor” because people seem to find this easier to understand.