Heating calculation for toilet in a basement

[ringer]

I have been asked to install a heater in a currently unheated toilet situated in the basement of a commercial premises. Please check my calculations and assumptions, and give your thoughts on my proposed solution

assumptions:
room size = 1.5m long x 0.85m wide x 3m high
U value = same for walls, floor and ceiling = 1.0 W/m^2 oC
ambient temp 2 oC to be raised to 18 oC so temp diff = 16 oC
air change rate = 2.0
ventilation factor = 0.33 W/m^3 oC

Heat requirement = fabric heat loss + ventilation heat loss

Fabric heat loss (W) = U value (W/m^2 oC) x area (m^2) x temp diff (oC)

W = 1.0 x 16.65 x 16 = 266W

Ventilation heat loss (W) = volume (m^3) x air change rate x temp diff (oC) x vent. factor (W/m^3 oC)

W = 3.825 x 2.0 x 16 x 0.33 = 40W

Heat requirement = 266W + 40W = 306W

So I'm calculating 300W but am considering fitting one 180W tubular heater (electric) and a timer, with the idea being to keep installation and running costs down and just remove the chill from the air. Toilet will be used perhaps twice a day.

running costs = 0.10 £/kWh x 0.180 kW x 8 hrs = £0.144 per day

 

[REDSAW]

so what your saying ?.
a 300mm x 600mm rad?.

 

[tamz]

No. He is saying why spend X amount on a small rad plus fitting when for 14 pence a day, no one will want to hang around in there reading the paper. Personally i think it would be cheaper to forget the heat and just lag the pipes😀

 

[tackleburger]

Bit of a waste of time calculating it out surely small rad TRV set at 2 would be fine, you can tell by looking at the room.

 

[spanner]

If its electirc it shouldn't need piping up just plug in and GO.
Say that was serious workage there, I'm heading your way but to see that illustrated I wish to have a marathon to make sure I got the backup.
Well done it looked illiustrating
But for the room size was the calculations easy or what??