Green Building Forum - Temperature sensor probes Mon, 17 Aug 2026 02:50:10 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38867#Comment_38867 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38867#Comment_38867 Thu, 20 Nov 2008 17:14:00 +0000 tony
The house will have a basement -- it is very easy to build in probes/thermocouples but quite difficult to retro fit them.]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38872#Comment_38872 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38872#Comment_38872 Thu, 20 Nov 2008 18:29:10 +0000 CWatters Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38878#Comment_38878 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38878#Comment_38878 Thu, 20 Nov 2008 19:45:20 +0000 Ed Davies Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38977#Comment_38977 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38977#Comment_38977 Sat, 22 Nov 2008 12:08:01 +0000 CWatters Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38979#Comment_38979 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38979#Comment_38979 Sat, 22 Nov 2008 12:19:53 +0000 djh Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38993#Comment_38993 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38993#Comment_38993 Sat, 22 Nov 2008 17:18:28 +0000 JackyR Posted By: CWattersSeems to work for heatsinks in electronics.
Not sure what you're saying works, but two possible contexts:
1) system maintains constant temperature difference between two points, power varies (any thermostatically controlled system, eg hotplate, heater when room at steady state);
2) system maintains constant power, temp diff varies (eg electronics, heater applied to slab which hasn't yet reached steady state).

To evaluate insulative properties, identify one quantity to be constant and then measure the other...]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38998#Comment_38998 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=38998#Comment_38998 Sat, 22 Nov 2008 18:00:13 +0000 Timber
They can be used to directly work out the thermal conductivity of a material, and the heat flow as well as temerature.

We use them at work for some of out 'reasearch' projects. I will find the specs and exactly what they do if you are interested.

Timber]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39013#Comment_39013 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39013#Comment_39013 Sat, 22 Nov 2008 21:40:23 +0000 Ed Davies Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39015#Comment_39015 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39015#Comment_39015 Sat, 22 Nov 2008 22:09:42 +0000 Timber
I didn't realise they were that much though. Still, if you are sticking them into a new build and plan to do some serious research, they may be worth it depending on how much extra info can be extrapolated.]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39019#Comment_39019 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39019#Comment_39019 Sat, 22 Nov 2008 23:54:23 +0000 Mike George
If Q = UA delta T

Heat loss [kWh] = u-value x temp difference between probes.

Therefore you need to be able to measure the energy used in the test to be able to calculet the u-value and hence the R-value]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39031#Comment_39031 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39031#Comment_39031 Sun, 23 Nov 2008 11:22:12 +0000 CWatters
I accept there is an issue of how you best model insulation so that the results are representative of the real world walls and roofs (Hot box, in-sutu etc) but I feel the situation for a floor slab should be much simpler and give results close to what you get in the lab. You have a known tickness of insulation with known thermal resistance. You can measure the temperature either side of the _insulation_ (just the insulation). Then work the numbers. Do this near the center of the floor and at a few places around the edge and it should be possible to calculate the power loss.

To improve accuracy you could even insert the probes a known depth into the insulation.]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39066#Comment_39066 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39066#Comment_39066 Sun, 23 Nov 2008 17:46:31 +0000 JackyR Posted By: CWattersI think you should try to install them in pairs either side of the insulation so the thermal resistance between them is known. Would help settle the issue of how much power is flowing through the floor.

Posted By: Ed DaviesCWatters, as the multifoil discussion has already pointed out, knowing the temperature on each side of or even inside layers of insulation doesn't actually help much with knowing the rate of heat flow.


Aaah, CWatters, you mean "either side of the insulation because the thermal resistance between them is already known". Some of us read that as "so that resistance between them can be found". *light dawns*]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39067#Comment_39067 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39067#Comment_39067 Sun, 23 Nov 2008 17:53:26 +0000 CWatters Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39070#Comment_39070 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39070#Comment_39070 Sun, 23 Nov 2008 18:09:46 +0000 Mike George
In the case of floors, the P/A method of calculating u-values based on 'known' steady state conductivities is also questioned by some [a minority including me] Once again using the said conductivities [of say PUR] as a basis for calculating energy use is not going to establish whether it is better to put the PUR in or not.]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39074#Comment_39074 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39074#Comment_39074 Sun, 23 Nov 2008 18:42:02 +0000 CWatters Posted By: Mike GeorgeThe point is though that it is the thermal resistance is what is questioned [at least in the case of multifoil] Using the hot box derived value does little to settle the argument..

Yes all of my commens above were with a floor in mind. Im assuming Tony would be using a rigid insulation like Celotex. I have more confidence that the figures quoted for solid insulation materials could be applied to the situation found under a concrete basement slab.

In the case of floors, the P/A method of calculating u-values based on 'known' steady state conductivities is also questioned by some .


That's kind of why it would be nice to have the temperature gradient at several different places on a floor, unfortunately the fact that it's a basement probably means we would see a much more uniform loss distribution. The standard P/A calulation wouldn't apply to basement floor.

Once again using the said conductivities [of say PUR] as a basis for calculating energy use is not going to establish whether it is better to put the PUR in or not.


No that wasn't my intention really (I assumed tony wouldn't be happy to insulate one half only) but it would just be interesting though to get a feel for the scale of losses through the floor. Almost a shame it's a basement.]]> Temperature sensor probes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39090#Comment_39090 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2976&Focus=39090#Comment_39090 Sun, 23 Nov 2008 20:53:55 +0000 JackyR