In an increasingly cost-conscious era, driven by environmental awareness, regulations, and overall health and safety, HVLP has fast become the spraying technology of choice in the woodworking industry.

Although HVLP spraying technology has been around since the 1960’s it remains relatively misunderstood by many users. As HVLP sprayers were gaining popularity in the 80’s they were being pitched by many as the ultimate solution to the mess associated with conventional spraying … but how do they really work? What is the difference between turbine-powered and compressor-powered HVLP systems? What should you consider in choosing one or the other? The goal of this article is to go back to the basics and use simple explanations in answering these questions.

There are two types of HVLP spraying technology: compressor-powered and turbine-powered.

What is compressor-powered HVLP?

Compressor-Powered HVLP guns are used with a standard air compressor. The internal diffusers in the gun convert the air from high pressure to low pressure at an approximate rate of 10:1 (the ratio varies from one gun manufacturer to another) thereby reducing the air to compliant levels by HVLP standards of less than 10 PSI. In other words, with inlet air pressure of 100 PSI, the pressure at the air cap would be +/- 10 PSI; with inlet pressure of 80 PSI, the pressure at the air cap would be +/- 8 PSI; and so on.

In order to compensate for the lower air pressure at the air cap, compressor-powered HVLP guns generally demand large amounts of air volume (CFM) from the compressor.  Typically, a range of 8-15 CFM @ 60-90 PSI (this varies from one gun to another) is required to achieve professional fine finishing results. A 5HP (220V) compressor is normally required to maintain that much air volume.  

What is turbine-powered HVLP?

Turbine-Powered HVLP systems are powered by an electric turbine (110V) that supplies a consistent flow of high volume, low-pressure atomizing air.

The turbine draws ambient air through the filters, amplifies the air through a series of stages in the turbine motor and delivers high volume, low-pressure air through the hose to the gun.

Because the turbine is designed to supply high volume, low-pressure air there is no “converting” such as with compressor-powered HVLP guns.  As a result, turbine-powered HVLP is often referred to as “True HVLP”.

Which system is right for you?

To determine which system is better for you, the first question you need to answer is...Does your compressor deliver enough CFM (8-15 CFM @ 60-90 PSI) to power a compressor-powered HVLP gun? Don’t guess on this one – check the spec sheet for your compressor or contact the manufacturer for confirmation of the air output – an under-powered compressor will be the difference between satisfaction and frustration with a compressor-powered gun.

If your compressor delivers enough air volume or you decide to invest in one that will, then you have the choice of either a compressor-powered or a turbine-powered system.  To make the right choice, consider some of the following:

Performance: When used properly, both turbine-powered and compressor-powered systems will provide equally as good a finish with all the benefits that HVLP has to offer - superior quality finish, reduction in overspray, material savings, etc. – and will spray virtually any sprayable coating, from stains to latex paint… even soluble adhesives.

Air Quality: Clean atomizing air is critical to the quality of any sprayed finish. While a good filtration system on your compressor will filter water and other contaminants from your compressed air lines, they can be expensive and a hassle to maintain. Turbine-powered systems eliminate these variables all together. Because the turbine simply amplifies air rather than store it like a compressor, there is no moisture build-up in the air lines. As long as the intake filters are kept clean, the turbine will produce a consistent supply of warm, clean, dry atomizing air at all times.

Portability: Considering the air volume required for compressor-powered HVLP guns, a suitable size air compressor is not normally portable. Turbine-powered systems on the other hand are self-contained, weigh as little as 30 pounds, are easily portable to any job site, and can be used anywhere 110V power is available.

Application Speed: Turbine-powered HVLP systems will meet the demands of a professional finishing shop spraying up to 8 hours per day. For higher-volume applications where spraying is a bottleneck, the inlet pressure on a compressor-powered gun can be increased to increase application speed. The increased inlet pressure may produce more overspray but as long as it is kept below 100 PSI it will still be significantly less than with any conventional high pressure system.

Cost: Both compressor-powered and turbine-powered systems are available in various price ranges and quality. The initial cost of just a compressor-powered HVLP gun is generally less than a turbine-powered system, however the additional expense of suitable size compressor and proper airline maintenance equipment – i.e. in-line filters, coalescent filters, dessicant filters, airline dryers – increases the initial investment considerably. As for operating costs, the long term operating cost of a turbine-powered system is significantly less than that of a compressor.

Contrary to popular belief, HVLP makes professional spray finishing easy. Because the material does not bounce back at you like a conventional gun, you can actually watch the material going on the surface, making it easier to overlap your passes and maintain proper spraying techniques. The end result will be substantial savings in material and operating costs, a cleaner, safer working environment, and a superior quality finish!

In summary, a quality HVLP system, whether turbine-powered or compressor-powered, will contribute significantly to lowering your costs, improving the efficiency of your finishing process and add value to your finished product.