zoneing a slab

Couderay

You could go under the drain keeping it several inches away from the sides and bottom of the drain. Have done it a few times by using two layers of 1" armaflex allowing for movement and or distortion.Armaflex works good when you want to keep heat away from areas not to be heated and when a monolithic pour can't be done.

Randy-Lee Braman

zones in a poured slab

Looked at a job today.100'x 50' Pole building.The plan is to pour a 8" thick slab which they would like to have three zones of radiant at different temps.The only way
i could figure to do this would to have each zone section
isolated by a insulation barrier in the slab,other wise heat would just migrate threw the sections,am i correct?
any ideas.
Randy-Lee

AL_29

heat tranfer minimal

Your heat transfer will be minimal. I have had great luck with individual manifolds and running 3/4 or 1" pex under the isultarp to my manifold locations. Just try to keep the t-stats near the middle of the zone. With a slab that thick you need to make sure the tube is only 3-4" below grade. Otherwise the heat will take weeks to get to the surface, and weeks to cool down. Making it scorching in the areas when we have a fluke warm up in the middle of winter. Don't forget outdoor reset. Honeywell makes a new controll for pumps and outdoor reset around 300 bucks. Just put one in on a 17 zone system. It working great.

Unknown

be aware there is no fast temperature change on a slab that thick. they might get 3 temps, but those temps will never change quickly.

heat migration would only be a concern on a very small zone.

Randy-Lee Braman

insul tarp

Al,
Are you useing rigid foam insulation under that insultarp or just the tarp.This system will have one small zone and then two larger zones.it will require at least 4 remote manifolds not only because of the size but they also plan
a 10" deep x 8" wide drain running the 100" length that i have to get around.
Thanks,
Randy-Lee