Radiant heat is like the sun's heat. It travels through the air until it finds an object (did you ever notice how hot the pavement gets in mid summer?). Typical heating systems rely on “convection”. Convention simply means that the heated air will rise, and the cooler air will fall (unless it's forced warm air, which is driven by a blower). Have you ever put on clothes that seemed to be cold? How about crawled into a bed that seemed rather chilly under the covers? That's what happens with convectiveheating- the air is warm, not the surrounding objects in your home. With “warm air”, your skin is tricked into thinking that the living environment is comfortable, until your skin has to give up its heat to another object! This subject becomes physiological as well: Have you ever stood next to a glass window or door and felt the cool air against your skin? Next time this happens, find a thermometer and go back to that window. Unless you have a literal draft of air coming in through the jams, you won't see the thermometer go down! That's because your body is giving its heat over to the glass, and therefore cooling off our skin! Remember, our skin is a breathing organism. That's why it's possible to feel comfortable with radiant heat at 68 F, yet feel cold and clammy with a convective heat source at the same room temperature.

As mentioned above, lower boiler temperatures equates to lower fuel bills. I'll have to get a bit technical to explain. For example, the average heating system is designed to circulate water between 180 F to 200 F. A properly designed radiant heating system will operate at around 130 F (actually, this can vary quite a bit depending on the flooring material used and where the heating tubing is placed). A commonly accepted rule of thumb is to figure 1% fuel savings for every 3 F you can lower the system temperature. [Example- a conventional system's 190 F vs. a radiant system's 130 F would be 20% more efficient (190-130=60. 60/3=20%)]. Hold on, it gets ever better! Most radiant heating contractors will figure into their quotes a control device called an outdoor reset. Don't skimp- this thing is for real. During the course of the heating season it will monitor the outside air temperature and adjust the boiler water temperature accordingly. Virtually all conventional systems have a basic boiler “aquastat”. The aquastat has a “high limit” that tells the burner to shut off when it reaches that pre-set limit point. Conversely, the outdoor reset control only squeezes out of the boiler what it needs to heat the house. The only time it won't be all that beneficial are the days that are “design conditions” (explained later). Here in Central New York to be specific, we heat about 7 to 9 months out of the year. How many of those days do you think we're at 0 F outdoors? Perhaps a better question would be, "How many hours?”. Most heating pros realize that we are at design conditions about 1% of the heating season. That means 99% of the heating season the conventional heating system is oversized!