under floor hydronic heat

nbmech

Hello,
I would like to add some extra heat to the rooms over a crawl space approx 500square feet. The bedrooms and hallway(350SF) are hardwood and the laundry and 1/2 bath (150SF)are tile. The thermostat is in a hallway and is set at 70F.
The crawlspace walls are insulated. The rooms off of the hall are usually 65-67 when the hall is 70. The wood floors are 62-65 and the tile is COLD.
I have baseboard heat with the water set at 180F.

I would like to add a zone to heat the floors from below. I understand if I attach the PEX to the underside of the floor I will need to cool the water to 120ish with a mixing valve so I dont damage the wood floor.

I am thinking of running the PEX on the bottom of the floor joist so I dont have to fight looping it around and wont have to add a mixing valve and hopefully I can keep the temp at 180 with no damage to the floors.
Any ideas??
Thanks

beenthere

Won't get much heat that way. And will end up drying out the joist, and probably warping them. Along with spending a lot more money on heating then you need to.