Supplimental electric radiant heat question

Brad White_9

One thing common to all floor radiation is the conductance to the space (where you want the useful heat) versus conductance to the ground or where you otherwise do not want heat. For the radiant heat to work properly, you have to have at least twice if not several times the resistance downward as you do between the radiant mat (or tubing, whatever) and the floor surface. Otherwise you will be driving the heat to the greater, colder mass. Until that mass is warmer than the room to the degree that you need heat, you get, forgive the Yiddish, bupkes in the room.

As for control, the heat is essentially switched. To have any control in a given space you need a switch (thermostat). By the term "slave unit" am I to assume that one must be in operation so that the other will work? (Series control?) I would not find that acceptable if I lived there. Go parallel and enjoy independent control.

rdwj

Supplimental electric radiant heat

I'm planning on installing radiant heat under the tile in my basement - I'm remodeling it. I have two issues that confuse me.

Many manufacturers recommend using an insulated backer over the concrete floor. Is that the same as standard underlayment or is it something different?
I want to hit two rooms - a 30 sq foot bathroom and a 100 - 120 sq foot bar area, but I want to control both rooms with one thermostat. There rooms are separated by a 6' storage area. Is there a way to do that without slave units?

rdwj

"By the term "slave unit" am I to assume that one must be in operation so that the other will work?"

It's a master / linked set-up separates the area into zones with a linked unit responsible for heating each zone

All power modules are "linked" with a master thermostat that controls temperature settings / programming for the entire floor.

The setup I was considering can be found here:
http://www.aubetech.com/products/produitsMaster.php

Brad White_9

I see

what is meant is that it is just one large zone.

The term master-slave can be ambiguous.

"If you want separate temperature control, then you need separate temperature control", simple as that. I know of no other principle which will give separate positive control.

(The term "negative control" for comparison would be analagous to a TRV on a radiator. It cannot call for heat, just deny it. It is slaved or secondary to another control which says, "I need heat" whereupon the slave zone says, "well, maybe I do not need as much". Hope that makes sense!