Best options for home temperature/humidity monitoring

Continuing the discussion from Thermal Imaging - as a tool for retrofit evaluation:

Some great discussion has been started here by @zapaman and @Peter_Mumford about home environment monitoring with temperature and humidity sensors. @Matt from Carbon Co-op has also been looking at this and I believe is also running some trials in the field with members. This could be a good place to discuss the best approach to monitoring!


I use the inexpensive Xiaomi Temperature and humidity Zigbee sensors with my Smartthings hub.
Also just started using the sonoff zigbee sensor as well, as they are sometimes slightly cheaper.

Could be integrated into the HEMS with a Zigbee dongle


Following on from Oscar’s post, I use the same sensors with a Raspbee dongle running HA.

1 Like

Sorry - where’s an explainer for what HEMS is?:smiley:

1 Like

HEMS - home energy management system that powershaper send out, basically a raspberry pi running home assistant.

Research ??? @matt @lloydham - I have a humidity monitor in my loft which is currently reading 99%. Condensation is all over the surface of my roof liner. Worrying!!! - for any homeowner who had just spent a small fortune insulating!!
Thankfully I received some great advice from within our community and I am tracking the moisture and the airflow.
It turns out we have stack effect !! - the cavity wall between the bathroom and the bedroom which is open from above in the loft. This cavity is full of super heated air which has been clashing with the cold air in the loft. The boiler pipes and radiator pipes reside in this cavity. Today I stuffed it from above with sheepwool insulation, then sealed it at the top with a piece of PIR board and insulating foam.
We have a number of other possible problems too.
A hole through to next doors loft who have a bubbling hot water tank which I am not sure whether it has a cover or not.
A void between the bathroom ceiling and plasterboard in the loft - both ceiling are full of possible air leaks via spot lights, speakers and holes for wires above in the loft
An exposed steel - boxed in with plasterboard in the bedroom below - we’ve pushed as much insulation around this as possible.
My loft has been sent to test me . I am sure of it!! It has made me probably the grumpiest housewife in Manchester this week. I can’t help but feel it has so many problems, that it would be ashame not to get some learning or research done for our members.
I will keep sharing. And anyone who wants to take a look is welcome.
I cannot deny that these problems are worrying, yet as I have started to learn the solutions - it’s fascinating too!
I hope my problems here can help others too x Carla


For those of you not on twitter:
Here is how I routinely track our household temperature together with how our energy use relates to this - giving a fairly rapid analysis of the thermal efficiency we are currently achieving.

I know that @Paul_Hadfield is looking into fitting around 10 humidity and temperature sensors, and is possibly following this thread as well! Just flagging this in case he wants to add his findings into the mix at some point too.

@Peter_Mumford apologies for missing this previously, and I’m sure you’ve since had a full explanation but this is the guide on the PowerShaper microsite- just in case you hadn’t been pointed to this before. Hope it helps, and happy to discuss further or field questions PowerShaper - HEMS User Guide | Carbon Co-op

1 Like

Thanks Polly. Yes, my key requirement is for ten or so inexpensive wired sensors to be sealed under my floorboards and to be functional for several/ many years (preferably for ever after - i.e. without needing batteries to be changed). Both the power supply and their signal outputs could I suppose ideally be carried by the wires - telephone cable? - if such sensors exist and are relatively inexpensive. I never want to have to lift my floorboards again just to get at them. I gather that these sensors need to be linked (by their wires I hope) to a hub/microcontroller of some sort in the room above, and as I have a Home Energy Management System (HEMS) under the Coop’s PowerShaper project it would be ideal if the microcontroller could in turn be wirelessly linked to feed the temperature and humidity data on in turn to that. Any thoughts greatly appreciated. They don’t need fancy cases, as they will never be seen again. I hope too that a switch could be incorporated in the system, so that it will automatically switch on a mains-powered fan to blow warm room air down there below the floor when/if necessary (I am bringing the underfloor space into the thermal envelope of the house, so am planning to close off the air bricks and insulate/air -seal the external perimeter, hence the requirement to monitor the humidity in particular).

1 Like

Hmm, similar problem here but not too bad as far as I can see. I put a load of extra insulation in my roof as I thought it sensible, so we’ve gone up from 3-4 inches by adding an other 200mm. Most of the roof has old (1980s) roofing felt and I’m now seeing some condensation on that. One area where we had an extension built in 2019 has breathable membrane, that’s fine plus area around it.

Worst area seems to be behind our solar panels. Next step - get some monitors up there so I can track temp and humidity on my Homeassistant. Xaiomi and Sonoff seem to be most used. Any recommendations?

@Matt-S and @zapaman will have some ideas on this, no doubt!

Thanks @polly. Yes Xaiomi or Sonoff sensors are very common and affordable.
In terms of just temperature a single EmonTH from OpenEnergyMon plus a daisy chain of multiple DS18B20 temperature sensors might be a good option. The EmonTH could be located somewhere accessible (for changing batteries)) and the DSB18820 probes could be inserted into the sub floor or loft areas where you need multiple temperature readings. These would not give you humidity but at least you would know if the temperature was getting low enough to cause concern about condensation.

1 Like

Thanks so much @zapaman @Paul_Hadfield here’s your starter for ten (sensors) :slight_smile: