How does an HVLP spray gun work?

The basic principle of HVLP guns is to “atomize” the paint using air volume rather than pressure, which means that when it meets the air stream, the paint is split into small particles as it is expelled from the nozzle.

All guns come with paint fan formation control, so you can adjust your fan size from small to large.  They also have fluid density controls to adjust the spray from a light mist to a thick mist. Some HVLP guns also feature airflow so that the operator can slightly adjust the pressure and volume from the spray gun.  Most HVLP guns also include a 600cc capacity paint reservoir, an air inlet and a nozzle that helps control the pressure and dispersion of the paint being sprayed.

Operation is simple: when the gun trigger is pulled, the paint is released into the air stream through the nozzle at the desired pressure and spray pattern. The result of a correctly configured HVLP gun is a fast and even coat with very little material waste.

What is the air source for HVLP spray guns?  This mechanism can be of two types:

1. An air compressor capable of producing about 25 psi inlet pressure, which is reduced to 10 PSI or less to propel the paint with less velocity. These are the most common type of HVLP spray guns.
2. Using a turbine system to produce large volumes of air, but at a lower pressure: approximately 6 psi. These types of sprayers are more efficient, and since they do not require a separate purchase of an air compressor, they can mean cost savings. In addition to saving on the compressor the turbine also produces clean warm dry air so that inline filters are not needed.

Turbine HVLP spray guns are rated at over 80% Transfer Efficient whereas compressed air HVLP spray gun are rated at only 65% Transfer Efficiency.  This translates into additional paint savings for the user.  In addition to paint savings, booth filters will also need to be changed far less, thus increasing the savings from turbine HVLP spray guns over compressed air HVLP spray guns.

In conclusion, both compressed air and turbine HVLP spray guns will save you a lot on paint, but only the turbine HVLP spray gun will give you the additional savings in paint along with no need for dryers and filters.