Quite often we are asked “Is radiant heat suitable for rooms with a cathedral (or sloped) ceiling”. The short answer is an unqualified yes!
Everyone is familiar with the concept that “hot air rises”. That’s true. Hot air is lighter than cold air and so it will naturally float to the top.
The key thing to note, from both a comfort and energy efficiency point of view, is that the energy you paid for to heat up all that air rises away from you and the other occupants and objects within the room.
When a room has a high or cathedral ceiling, that effect is only increased. You either have to employ a fan to help push down the hot air (using more energy still to power the fan, only to have it rise back up again), or crank the heat up even further in the hopes that some of the hot air will eventually reach you.
That’s not particularly energy efficient is it?
Radiant Heat is Different
Radiant heat does not heat up the air directly like a hot air system does. Radiant heat warms objects and people directly.
Think of radiant heat like sunlight. It “shines” on all the objects and people it can see. That “shine” is what warms you and the objects within the room. Just like the Sun warms you directly on a clear day.
Directly, instantly and efficiently.
Ceiling height isn’t a factor in how far radiant heat can travel. The Earth, after all, is warmed by the Sun which is some 93 million miles (149 million kilometers) away.
Since radiant heat doesn’t heat the air directly, there’s no hot air rising (and no cold down drafts)in the room, and thus the warmth is evenly distributed throughout the space.
There’s no need for fans and other additional “tricks” to try to coerce the heat to where you are—at the floor level. Radiant heat does its job effectively and efficiently.
As you can see, hot air systems cannot effectively nor efficiently heat a space that has a high or cathedral ceiling. Only radiant heat can do the job.