While a 1500W (115v) heater won't heat an entire 2 car garage, it will still help. I have a portable A/C that has a heat pump setting for winter heat and it can normally make the garage comfortable enough to not need a jacket but when it is really cold or I have had the heat off for a few days, I use a 1500W IR heater to give it a boost and heat things up more quickly. I have it over the where I stand when working at my bench and it makes a huge difference by creating a nice zone of comfort until the A/C - Heater can catch up.