pressure & state change

[drkillroy]

An amonia absorbtion refrigeration system uses nitrogen to cause a temperature change in the evaperator. If an amonia gas is trapped in a chamber at normal system pressure, then nitrogen is injected, will there be total pressure decrease within that chamber? External chamber temperature will decrease 60 to 100 degree F temperature range. I don't know if the injection of the nitrogen gas will replace the gas volume that changes into a liquid.
Thanks Dr Killroy