I'm also going to use the same principal to cool and heat the chamber, I'm going to have a liquid with a low boiling temperature, like alcohol, sitting in pipes running through the walls of the chamber. Ill then pump out the air around the alcohol, making it boil from low pressure. Ill then pump the alcohol vapor out of the pipes and pressurize it in a jar, recondensing it. I could also do the opposite to heat the chamber. It should make a nice heat pump.