Most but not all appliances can be converted from natural gas to propane.
Can you convert a natural gas wall heater to propane.
The biggest sticking point is that natural gas is kept at a lower pressure and some appliances can t handle the higher pressure of propane even with adjustments.
I have no idea if this is safe first of all or how to begin to go about it.
A lot of grills are already ready for a propane conversion.
People i have talked to say it is easy to convert to propane which would be much easier i think than running gas lines to the greenhouse.
They either come with the hose assembly required or you are able to order it through the manufacturer.
Most space heaters are no longer convertible you must by the unit on the gas that you are using at your home.
I have a vent free natural gas heater made by procom.
Step 1 remove old hose.
Using the wrench remove the hose from your natural gas source and make sure that it is capped or shut off.
You can convert some appliances but others are designed to burn only natural gas.