I am starting to plan the floor heat layout for my garage addition, and was wondering what everyone recommended for the tube to install the floor temperature sensor in? Can I use a piece of galvanized electrical conduit with a 90 degree bend to come out of the floor? How far into the slab should it go? My floor will be approximately 8 inches thick with the pex tied to rebar that will be on stands about 3 inches from the bottom. Thanks in advance for any advice!
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Radiant heat floor temp sensor tube question
- Thread starter 1233user
- Start date
Highbeam
Well-known member
Don't you have any leftover lengths of PEX? That's what I put in the slab for a temp sensor though I doubt I'll ever use it.
Don't you have any leftover lengths of PEX? That's what I put in the slab for a temp sensor though I doubt I'll ever use it.
I could use Pex, I just didn't know what would be the best. I thought that the metal conduit would transfer the temperature better to the sensor.
KenB
Well-known member
What control would use the floor temperature as input? Just curious.
Ken
Ken
Highbeam
Well-known member
What control would use the floor temperature as input? Just curious.
Ken
There are a couple out there that regulate slab temp or use it in conjunction with the room air temp and outside air temp to predict the needed run time of the heater.
These stats are expensive and in general folks are very happy with just an air temp stat.
I just imagine monitoring room temp is fine until the overhead doors are open and the air temp drops 30 degrees in the room. The air temp stat kicks on the boiler, the doors are shut, and before the running boiler has any impact on air temp the slab is able to reheat the room air and the air temp stat shuts the boiler off. Seems to be a waste.
Since slab temp takes many hours to change and air temp changes in seconds there will be some lag.
So bottom line is adding a scrap piece of pex in the pour as a slab temp sensor sleeve is easy and cheap. Only get one chance and you may want to monitor it for thrills.
anthony666
Well-known member
^^ ditto, a 3/4" conduit elbow fits 1/2" pex .. tape the end that goes in the slab & position it in the middle of the slab away from the feed lines & centered between your runs
Highbeam
Well-known member
The slab sensors I have seen are like a thermocouple bulb attached to two stranded wires. It would be like pushing a rope. As such, the very smooth polymer interior of the pex is about ideal.
tdkkart
Well-known member
I could use Pex, I just didn't know what would be the best. I thought that the metal conduit would transfer the temperature better to the sensor.
If you think metal will be better at transfering heat, why are you using plastic for the hot water??
I ran an extra length of tubing out into the middle of the slab, just in case I decided to use a floor temp sensor. 3 winters later I'm still using the wall mounted air temp thermostat, works just fine.
Thanks for all the replies! How hard is it to slide the temperature sensing bulb through 8 feet of 1/2" pex tubing?
I taped it to a chunk of single conductor wire and slid it in.