Hey Farmpham, I'm growing in a garage and winter is coming up. We see snow/ice, though I'm not in Michigan (brrrrr). Lights keep the room hot enough but during dark cycle (daytime hours), temps obviously drop a lot . Rather than run electric heaters, was thinking maybe a propane heater since it will run when I'm not in there . I know the extra co2 is better for lights on cycle. So I'm here asking and brainstorming . Advice?