I do add a little heat to my coops (well, only my main coop so far, as my bantam coop hasn't seen a winter yet). I like the radiator looking contained oil units. That unit you linked looks very iffy to me safety-wise. Other safe options I've read about here on BYC are the sweeter heater and other flat panel heater types. I'm not sure yet what I'll use in my small coop. I have used a little clay pot "heater" in a tiny, temp. coop I built, and it worked great.