Watt Garage Heater This 6,000-watt garage heater from Heat Storm produces up to 20,000 British thermal units (BTUs), warming up to 1,000 square feet, making it a smart choice for most garages. It’s Wi ...

Whatever option you choose, it's worth noting that upgrading your garage with underfloor radiant heating is not exactly a DIY option, as there tends to be electrical and/or water work involved.