There are several factors to consider when choosing the right vacuum pump system for your lab.
Traditionally, scientists and technicians have mainly used oil-sealed rotary vane vacuum pumps for lab work. However, these pumps come with a few disadvantages, because they:
Require regular oil top-ups
Are expensive to run
Require regular maintenance
Release some oil mist into the immediate atmosphere (even with oil filter hardware)
As a response to these drawbacks, dry (i.e. oil-free) pump systems have emerged as a favorable alternative. However, you will still need to think about your laboratory's needs in order to select the right pump system for you.
Here's a list of factors you should consider when making your decision: