A recent article in Fluid Power Journal provides a useful look at when an air compressor pump, combined with a venturi, is the best way to create a vacuum, and when an ordinary vacuum pump might be more efficient.

Both achieve approximately the same effect, but in many cases people specify a vacuum pump because they feel they do not have sufficient compressed air to work with a venturi.

The article asserts that this is often not true – and that substantial efficiency gains may be made by using air compressor pumps and venturis, rather than an always-on electric or hydraulic vacuum pump.

For example, the journal gives the situation of a vacuum-lifting application where suction is needed for three seconds in every 15.

A 0.25hp vacuum pump will typically run continuously throughout each 15-second cycle, whereas with a venturi, only three seconds of suction is needed, with a valve shutting off the compressed air for the remaining period.

This means a 0.9hp venturi would only use 0.18hp of compressed air, on average, for one fifth of the 15-second cycle.

As a result, the air compressor solution can be substantially more efficient than using an electric vacuum pump, particularly in such instances where the need for suction is periodic and not constant.

Fluid Power Journal