Posted: 07/02/2014 at 14:09
This is for a g/h that is 6'x8'. I only had it installed in the Autumn and it has not been that cold yet, but I have a min and max thermometer (Amazon) which tells me how cold it gets at night and so far it has not dropped below 0, next year I think I will get some insulation on for the winter as well as the heater.
Hope this helps
If you have any more queries, I'm going out at 4.30 and will be seeing the electrician who installed it.