Harold, This was my original thread - Thanks for the input. May I explore
your comment further. Are you saying that for the general use of a gas
heater to keep frost at bay in wintertime, and with a thermostatic control
on the heater then Venting for safety reasons should not be a worry -
assuming that i do not stay in the green house with the heater on and the
door shut - of course???

regards Ramon



8-))////////////////////////////you might suffocate if you have the heater
on 24 hours per day and you sleep in the greenhouse........I am still
alive
and never vented when using my propane heater......and, as David Hill
said,
carbon dioxide is a benefit. Large commercial greenhouses owners spend
big
money on a carbon dioxide generating system.

Harold W.