HVLP stands for high-volume, low pressure. They are more efficient and cause less over spray than standard spray paint guns. If you do a lot of spray finishing, an HVLP spray paint gun can save you money over the long run because you will use less paint. You can use your shop air compressor's powerful air output to run a spray paint gun. A trigger operated spray paint gun takes paint or finish and mixes it with high pressure air. The paint is atomized and sprayed out in a cone shape to produce a neat and controllable pattern. An experienced painter can produce very nice finishes smoothly and with a professional look. HVLP spray guns are widely used in automotive shops to produce factory quality finishes. Most HVLP spray paint guns allow you to change out nozzles for different types of finishes. Examples are lacquer, stains, paint and varnishes. However, thick latex paints are not advisable. (You can't use your HVLP spray paint gun to paint the house.) Most spray guns have a 1 quart cup that attaches below the nozzle and others have a top mounted cup. These are referred to as gravity feed spray paint guns. HVLP spray paint guns require large amounts of air to operate for continuous spraying. The paint gun manufacturer should tell you in the specs how much air is required to operate their gun.
One important thing to be aware of is that HVLP sprayers cause lots of over spray and will make a mess. It is very important to wear paint coveralls, breathing protection and eye protection. Also, masking and wheel covers are important to protect the car you are painting. HVLP spray paint guns are not precision instruments. It is more like a shot gun approach to painting. They are very good at applying a professional finish but they also blow paint everywhere. Body protection is very important when using HVLP sprayers. You can get away with minimal protection when painting a room in your house, but with these tools you need to make sure your whole body is well covered before you begin spraying. Because they out so much and in such fine mist, breathing protection is absolutely mandatory. Tiny droplets of paint will be suspended in the air and you will inhale them without a respirator mask on.