Hey gang. I have a tandem 3-car attached garage (right hand side is 2x as deep as the main garage and the main area is approx 18x18) for a total of approx 525 sq ft with 11' ceilings. The garage is sheetrocked and I am assuming it is insulated but I am not the original builder - but logic says it should be. Concrete slab floor and foam panel insulated door with the Master Bdrm overhead. I plan to do most of my composites construction in the tandem right side and "stage/prep" my work on portable benches on the left hand side so I can still park my wife's car inside at night. Here in south Denver, we get winters where the temps can get as low as 35F and as high as 95F in the garage, but those are few and far between. Typically, garage temps will vary between 50F-85F, but that's still outside the range I want or can tolerate with composites. So I am looking for efficient ways to bring the temps up quite a bit and down a few degrees when necessary. I suspect my heating months will range from Sept-May and my cooling months from July-Aug only (not uncommon to see 30F-40F swings overnight here, even in the summer) So....any recommendations would be helpful, but I am thinking of a portable swamp cooler like this one. I am wondering if this might create more humidity than I want. It's already very dry here in Denver, with RH between 40-68%, but not sure what these units will do to that. Also not a clear spec on what type of temps drop I should expect with this unit. Anyone know how to calculate that? For heating, I am trying to avoid anything with an open flame, but I also don't want something with a fan blowing dust around. Thinking about an electric infrared radiant tube heater like this one. Figured I could install 2 or 3 on their own switches so I can heat the garage quickly but maintain only the areas I am working in. My main concern with these is how "localized" the heat might be and if I would end up creating "hot spots". Oh, and one last thing....I would like to do this in a "non-permanent" installation. With the exception of some 240VAC power I plan to install anyway, I really don't want to start piping gas and venting through the walls. OK. Let 'er rip! Am I on the right track? Any specific experience with these types of units? Thanks!