On Wednesday, January 15, 2020 at 2:21:59 PM UTC, Cynic wrote:
Ask a couple of the heat hire companies for their thoughts on reliability of what's available. I recall some off tune/ badly adjusted portable, direct oil fired blown heater units being dreadfully obnoxious to smell if working in the same space.
Probably better to think about a 50kg bottle of propane and a gas unit.

Thanks for the input Cynic. I have a ready supply of diesel so that would be the preferred power source beside I have memories of bottled gas fired room heaters which had obnoxious (to me) odours.

The present unit is an Andrews model but they are now very expensive. It has given me good service and after 20odd years I now know all its foibles