Contact Bigleo. He has a great setup I think.
Bubbles, I'll chime in since Waxman has volunteered me
First, my systems have some controls to them as I have floor heat & de-icing (which are not the same). I suspect you are talking about de-icing.
For de-icing, my controls measure the temperature on the return manifold to get a sense of the slab temp. It modulate the circulation pump to make sure I don't crack the slab (so it brings up the slab temp slowly) and maintains it. Now you can do this yourself by bring it up slowly over a day, but without the controls, you'll be switching the circulation pump on and off (instead of modulating) at a hysteresis set in your thermostat. Not as efficient, but not terrible either.
I also use a infrared thermostat gun to measure the individual return legs of the floor heat and control the flow through them to balance out all the loops. This helps to avoid hot or cold spots. I also use the infrared gun to spot check the floor and make adjustments as required. I also added a circulation pump for one long loop I could never get up to temp. It's good now.
To be more efficient I use to change the floor temp daily (up when it's cold, down when it warms up). In my case I found that micromanaging the floor temp created problems as it just takes too long to get the floor temp back up when it gets cold. For example, if the cold snap was sooner and colder than expected, I couldn't get the temp back up to where I needed it to be until it warmed up. So now I just set it and leave it unless there is an expected warm up that's more than a few days.
Hope this helps. Big
