I have used 2 of these in both my garages. 8kw gives an unbelievable quick heat, and CLEAN / NO smell of diesel since the exhaust has a separate steel-hose going outside of heated area. Remote control works perfect. Step-by-step adjustable from 1-8kw. Muffler is meant to be used outside, since it is not 100% closed (it has a leak-hole for unburnt diesel). If in doubt; just buy it!