Example= 6' (H) x 5' (W) x 6' (L) =180 / 50 = 3.6 Kw. This is the basic size needed but this needs to be adjusted, ask your self ,is the sauna indoors or out doors, is it very well insulated?. example= if the above sauna is indoors a 3Kw heater will be fine if outdoors with only standard insulation then a 4.5Kw will be better.
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