ᐅ Which bathroom radiator should I choose, and what wattage is needed?

I want to renovate my bathroom, but I am completely unsure which heated towel rail to buy. My bathroom is about 10 m² (108 sq ft) in size, with insulated exterior walls and a new window. The heating system is a gas condensing boiler. How many watts should I choose at minimum? When searching online, the information is very confusing... Thank you

steelers77 schrieb:
How many watts do I need at a minimum?

The required power depends on the room heat load. The output ratings of the radiators are provided by the manufacturer for defined conditions (flow temperature, return temperature, RT) under standard conditions, e.g., DIN EN 442. If these conditions deviate, a correction is necessary. The required mass flow must correspond to the needed output.

Best regards

Since I was in the same (emergency) situation as steelers77 until recently, here’s my two cents:

There is a simple rule of thumb to calculate the required heating capacity for a room. It goes like this:

Room size x heating power = heating load (i.e., how many watts you need).

Heating power for new buildings: 100 watts per m² (10.8 watts per ft²)
Heating power for old buildings (not insulated): 150 watts per m² (14 watts per ft²)

So, if it’s a new building and a 10 m² (108 ft²) bathroom, it looks like this:
10 m² (108 ft²) x 100 watts/m² (10.8 watts/ft²) = 1000 watts

Your bathroom radiator should therefore have at least 1000 watts of heating capacity.