[Rhodes22-list] Speaking of Winter - Heating Question

[Brad Haslett]

I'm hoping some of you cold weather types have already done the math on
this.  I need to add some type of supplemental heat to the hangar.  It
doesn't need to be toasty warm, just warm enough to not see your breath
(like this morning).  Most of my hangar neighbors have large heat pumps, but
then they own their hangar, I rent so a permanent installation is not an
option.  The obvious choices are a portable kerosene or propane heater.  Has
anyone done the homework and determined which is most efficient at todays
prices?  Natural gas is not available external storage of propane probably
isn't an option either.  Either way I'll be lugging fuel supplies, bottles
or cans.  240 volt electricity is available and I currently don't pay the
electric bill.  That of course would change if I started spinning the meter
off the wall. Who has done the homework assignment on this and has figured
out which is the cheapest?  We're talking about 4000 sq. feet of well
insulated space with a 20 ft ceiling.  Ideas?

Brad