Has anyone used a catalytic heater to heat a tortoise "barn"? I will be heating a 8 foot w x 10 foot l x6 foot h building. That should require 2,500 btu heater. I have found some 3,000 btu heaters. I am still researching and figuring out lp gas consumtion to figure costs vs electric heat. Any info you know would be appreciated. Thank You.