Wondering about overhead radiant tube heaters. I will need to heat a garage roughly 900 sq feet with 11' ceilings. I'm looking at a 10' ng radiant tube, the input btu is 40k and the output is 31540. Does that sound like pretty poor efficiency? I can't find output numbers from any other manufacturers to compare to. Is a 10' tube long enough? I'm in British Columbia and we see maybe -20c but mostly around -10c for most of the winter. Garage will be well insulated. Thanks
