What do you mean by "Low Intensity Infrared garage heaters"? 'You mean the
electric powered ones or...?
I used a pair of nat. gas powered infrared units in the pumphouse of a car wash I once owned. They worked like a charm. 'Thermostats worked completely independent of any outside power source. IOW, even if all the power in town was knocked out
for days - the pumphouse stayed warm as toast regardless. ('Only needed ONE to heat the area, but, I installed TWO in case the thermostat on one of 'em
died...or one of the units itself died. That way the pumphouse would
still be heated.)
They looked a lot like these:
http://www.northerntool.com/shop/to...ci_sku=17353&gclid=CPX8msnckcICFQWTfgodCFQAYQ
Propane units are avail. too...
(Edit: Now that I think about it, I believe mine
were "Mr. Heater" units.)