Hello,

I have a cottage in Canada that is 800sqft well seal building. My suggestion to you is take about 10 gallons of RV low temp antifreeze and set up a system that you can replace the water with the RV antifreeze. To put any heat system in a building that is not well sealed is not a wise move ... and easly corrected with a couple of dozen tubes of clear caulking and a source of smoke and a flash light on a windy night and you should be able to seal up the building.

For a report I found useful was " LABORATORY TEST REPORT for Fujitsu 12RLS and Mitsubishi FE12NA Mini-Split Heat Pumps by Jon Winkler... Google it!

In my situation with an adv. Temp of 32°F I used 5 Kwh per day 150 Kwh per month which added $18 US to my building to keep it at 50°F.