heating with a pressure cooker ?
 

I have a 6 by 12 foot unheated greenhouse attached to the southwest side of the house. We heat our house with solar and wood. I was thinking that when I empty ashes and coals I could put them in an old pressure cooker. It should seal tight enough to keep any further combustion from happening and any carbon monoxide or other combustion fumes from bothering the plants. Any comments or ideas ?

Without further combustion, the heat content of the embers is probably a lot smaller than you think! You also would have to let the pressure bleed out or it might fail (explode). I bet filling it with hot water (heat at your fireplace/stove) would be safer and more effective.

Aluminum is a good conductor of energy be it heat or electricity.
It wont stay warm long.
Carbon monoxide rapidly oxidizes to carbon dioxide which plants live off of.
It wont hurt the plants but it might hurt you if there isn't an air exchange.

A big old cast iron container would work better, but even then it wont last long.

I have no idea it wont hurt anything give it a try and test with a thermometer it wont cost anything.

We used to set out coal and ash bucket on the porch I dont remember how long it stayed hot.
Remember aluminum melts at around 1200 degrees.

Like was said above it might build up pressure.


Worth

I was thinking of a pressure cooker with the rocking weight for pressure control but a cast iron Dutch oven should seal tight enough. I knew there was a better idea on how to do it. Sometimes there are live coals in the ash bucket 24 hours later. It is covered with a loose lid so wind doesn't blow ashes/coals out.