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  • Radiant heat used to be installed in uninsulated buildings constructed upon an uninsulated concrete slab. These buildings were hard to control because the slab and the earth underneath, with its huge thermal mass would not respond promptly to changes in the buildings need for heat.
  • The engineering literature of the time indicated a need for complex controls that used an outside thermometer and reset controls to get a “jump-start” on changing conditions. But a very important factor was overlooked.
  • Outside air temperature is only one factor in a building’s need for heat. Other factors are equally or more important and these controls do not address them. Radiation from the sun is important as well as radiant losses to the night sky. Wind and internal heat gains are also quite important.
  • It is our opinion, and our experience, that if a building is reasonably well insulated, and if the slab is insulated away from the earth, or if a wooden floor system is used, the problem does not exist to an important degree.
  • Our fellow professionals and competitors are entitled to their opinions and we have ours. These controls may be a poor solution to a problem that no longer exists.