Heated ceiling in a bathroom

Sizing for short use

A bathroom is occupied for a few minutes a day, but at those precise moments the body is undressed and still. Sizing therefore does not follow the logic of a living room: it is not the average power that counts, it is the ability to produce a sensation quickly.

What low inertia changes

A low inertia radiant system reaches its working temperature in a few minutes. That allows an intermittent heating profile: a low setpoint held permanently, with a boost programmed before getting up. A high inertia system does not allow that profile, it has to be left running.

Power per square metre

It is set by the ceiling area available, less the cut-outs for downlights and ventilation. In a small bathroom the area is limited, and that is what constrains, not the technology. The calculation is done at the survey and decides whether a secondary source is still needed.

Felt comfort against air temperature

With a radiant ceiling the sensation comes before the thermometer moves. An occupant judging the result on the thermostat will conclude too soon; one judging by sensation will find the opposite. That is a point to explain at commissioning.

What not to expect

A radiant ceiling does not dry towels. If that function is expected, it still has to be dealt with separately, and it is better said before ordering than left to become a disappointment afterwards.

The case of a very small volume is dealt with on the toilet page, and the temperature readings on the bathroom measurements page.