Installed in a campervan, yes they are very good, they will keep you as warm as you like. You can run them overnight from a fully charged lesuire battery & they use gas at the rate of around 140grams/hr. 1000grams=1 kg so you can work out from that how long your gas bottle should last, ie around 27hrs continuous running from 3.9kg Calor propane bottle.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.