concrete floor
the pex is inside the 3 inch's of concrete 5000 ft of it me and the wife installed. it is back breaking work. the owb runs about 180 but the floor water mixes to what the computer tells to based on outdoor temp. the only problem so far is the floor gets heat up and the thermal mass stays hot for a while so the owb does not fire for a long time and has gone out. I've up the house and garage temp to help to keep the stove going. i know when it gets cold this will not be a problem then just on the 30 degree days it will go three hour before she fire again. i also had to cut back on the forced induction it was forcing the fire a the way to the back of the stove. changing the induction seamed to fix all my flame out problems. it stays burning now at idle for a long time now.