View Full Version : Vacuum pump and moisture

27-04-2017, 09:11 PM
Dear Friends,

I have a question, I was talking with some of my friends inside of domestic forum in case of HVAC systems.

My friends divided in two cases below :

1 - Some of them believe that with vacuum pump we can evacuate small parcel of moisture after a couple of hours that vacuum pump works

2 - Others say with vacuum pump we can't evacuate moisture form inside of system and vacuum pump is not for this job.

Would you also please share your opinion with me ?

Sincerely yours.

27-04-2017, 10:41 PM
Those who believe no.2 do not understand vacuum. With moisture there can be no vacuum.

Vacuum boils moisture in accordance with steam tables.

28-04-2017, 01:39 AM
One important factor is to use the correct size vacuum pump always change the oil in the pump on a regular basis,triple vac as much as possible and remember to always use a torr gauge myself I prefer the old fashioned type I just don't trust the electronic type.

28-04-2017, 04:08 AM
A vac pump is the perfect tool to remove moisture from a system. Although using a vac pump, you can actually freeze the moisture if you vac too fast, then it will not be removed by the pump.
This is where "triple vacuuming" is useful.
To triple vac you evacuate the system, charge system with dry nitrogen, change vac pump oil and repeat. Untill you pull a vacuum under 500microns and does not raise significantly.