When the temp gets really cold, I put 2 heaters in truck on 2 different circuits and also put a blanket over the truckmount.
One way to know if the heaters on different circuits is to plug in both heater and set them on high. Little heater on high draw about 12 amps so a 15 or 20 amp circuit...
if the majority of your puchases are in the last quarter of the year, you will have to depreciate it using the mid month convention.
A way to avoid this is to section 179 the amount you want to depreciate.