How well a Ceilingo radiant ceiling actually works

Efficient means three different things

Conversion efficiency, the comfort obtained per watt installed, and the real cost over a season. Those three definitions do not rank systems in the same order, and confusing them explains most of the sterile debates about heating.

Conversion efficiency

An electric emitter turns all the energy it receives into heat. That criterion therefore separates no electric system from another, and putting it forward adds nothing to the comparison.

Comfort per watt

That is where the systems part company. Radiation directed at people produces a sensation of warmth at a lower air temperature, which reduces the output needed for equivalent comfort.

The cost over a season

It depends mainly on two things: how fine the control is and how good the envelope is. An excellent emitter in a poorly insulated home consumes more than an ordinary one in a treated home.

What a closed plenum brings to the calculation

Reflective insulation behind the heated surface sends back into the room the share of radiation that would have gone upwards. That recovery cannot be seen, and yet it shows directly on the bill.

How to measure it at home

By comparing two heating seasons over the same period and with the same habits, corrected for outdoor temperatures. It is the only honest method, and it requires a full year before concluding. The electricity supplier's readings are enough, provided identical periods are compared and the degree days are not forgotten.

The expected consumption is set out on the dedicated page, and the principle on the passive heating page.