as its starting to get colder ,i've found a redundant elec' wall heater from my old kitchen i'd like to mount it to the underside of the rafters but wonder if it can operate in this position, it has a 2 position heat setting & a 5 position adjuster inc' a frost setting there are no information labels on it ,its 1140x440x 50mm & has a short [160mm] sealed copper tube on the back,which i presume is a sensor ,theres no moving parts so i guess its a convection model,is it safe being upside down?