I am also in the Chicago Area, Crystal lake to be specific. I have my
shop half insulated which supprisingly does not make my shop half
warm. But, I and 2 brother-in-laws bought heaters at the big box for
about 100 bucks that hangs on the wall, runs on propane and has a
thermostate and fan, works well in one of their garages, ok in the
other and bad in my shop, but I believe that is because of my
insulation and loft.I bought a 60lb bottle for mine and as I am gone
14 hours a day during the week, I do not keep it on. When the Chicago
cold hits, it can never fully catch up. The air will be comfortable
(to me) at about 45 to 50, but the cast iron on the tools never seem
to get much past the "skin sticking" stage. Someone else on the wreck
from our area told me that we need a 2 pronged approach, a gas/propane
for the air and an infra-red for the tools. I am going to give this a
shot. Lowes has a nice one for about 100 bucks that I am going to
install above my TS and see if it helps.