Vacuum Pumps

[jvc]

Technicians at home always use vacuum pumps after they have worked on fridges or A/C units.

I have never seen one being used in Thailand. How do they manage without them? Is this bad for the equipment being serviced?

[cali4995]

I've seen/heard a few being used. It's supposed to draw down the system and remove

contaminants , i.e. water, debris etc. Often you can get by without it but this isn't the

optimum technique. I suppose as long as it works in the end, who's the wiser.

[Tywais]

Guess depends on the technician. Everyone that I have used if the freon is completely gone will pump the lines down before charging to remove the air (and that is important). If it is a matter of topping up the gas then the pump isn't normally used. This includes both my house AC and my car AC.

[cali4995]

I've only got experience tinkering with some automotive systems but as Tywais points out,

the principles are the same. unless the system has been "opened" to outside air, only

recharging or adding lubricant it's generally not necessary to vaccuum it down. If, on

the other hand components have been replaced or assembled for the first time then it

would be advisable to do so. I've seen techs use it on home systems so I gather they're at

least as competent if not more so in their use, since ac is used more frequently here.