Good question. You’re pulling 24” Hg of vacuum and then allowing it cool which will increase the vacuum but by how much?
You need the GayLussac Law for the answer.
The expression Gay-Lussac’s law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though it is more usually applied to his law of combining volumes, the first listed here. The first law relates to volumes before and after a chemical reaction while the second concerns the pressure and temperature relationship for a sample of gas often known as Amontons’ Law.
http://en.wikipedia.org/wiki/Gay-Lussac%27s_law#Pressure-temperature_law
Pretty easy to figure out once you know the boiling temperature where you live.
Jack, you should live in Europe, where the Weather Nazi gives you the info according to the Scale of Torricelli. Very important as it will affect fuel consumption of Panzer units transiting the Fulda Gap.