I started my shop a little over two years ago. I had it mostly completed by June or so of last year, but was busy and just didn't the heating system completed. All last winter I used a space heater, burning through I don't know how many tanks of propane. All the time, the on-demand water heater and the manifold was installed on the wall. All I needed to do was put up the thermostats and control box, then fill the system with water. I swore I would get it done this past summer.
Suddenly I realized it was October and getting colder and my shop was getting a bit cool during the night so first thing in the morning I was wearing a jacket. I kicked myself in the behind and a week ago took the time to get things put up. It took all of about 90 minutes to install the thermostats. Then last Friday I started filling the system with water. I have a single zone, with four loops of tubing, and it took me about 3 hours to get it all filled using just at 14 gallons of water. I used distilled though not sure I needed to. I did not put in any antifreeze as I don't intend on letting the place freeze. I may change that at some point, but for now it is just clean H2O.
I fired up the water heater on Saturday afternoon and thought it would take 4-5 days to get the floor warmed up. I went out on Sunday morning to check it and wonderfully the place was a nice 68 degrees or so. I had to turn down the thermostat because it was actually too warm. I fought the cold all last winter, making trips to the propane depot half a dozen times with 4 - 6 bottles, endured the smell of the burned propane, all because I didn't take the 5 hours to get the system finished. I ask myself at times, How dumb are you to not just get it done?
I can now say that it is incredible to have radiant heating up and running. Had to have the overhead door open for about 90 minutes loading some cabinets into a trailer and when I closed the door, the shop still felt nice and warm.
If anyone ever is considering radiant heat, don't think, just do it.