On a sunny spring day you can feel comfortable outside in a t-shirt and shorts even if the air is only 60ºF (15ºC). This is because we are feeling the radiant warmth of the sun. This radiant heat allows us to be comfortable at lower temperatures. The same is true in a radiant home. With the warmth of the infrared “shining” on us from the floor, the same comfort can be achieved with the thermostat set a couple of degrees lower than you would need in a home heated with forced air. Interestingly, when outside on that same mild spring day we may be comfortable until the wind picks up. Even though the air temperature has not changed, air moving rapidly across our skin causes evaporative cooling. Paradoxically, blowing hot air from a duct can cause you to set the thermostat to a slightly higher temperature to maintain the same comfort achieved in a radiant home at a lower set point.
