Which one should you use? That depends on your application. At first glance they seem to operate in a similar manner. But when it comes down to it, one really is better suited than the other, depending on the task it is being asked to perform.
I spoke to a customer last week who was currently using a 1″ Line Vac to transfer pieces of very small OD water drip tubing. He was looking for a way to increase the efficiency of his application, namely decreasing his air consumption while still achieving the same transfer results. His suggestion was to move to an Air Amplifier of similar size, since it has higher air amplification than a similarly sized Line Vac. He mistakenly took this to also imply higher velocity, which is not actually correct.
For moving a material that has any considerable mass to it, i.e. anything heavier than air or steam, a Line Vac is nearly always the best option. While a Line Vac does have a much smaller air amplification ratio than an Air Amplifier, it also has a much higher vacuum level. Thus, it is better able to pull solid materials through than an Air Amplifier would be. It can lift the weight and transfer it over the required distance using a ring of directed nozzles to push the material through.
An Air Amplifier is much better at moving large volumes of air in a short time frame. It is able to quickly entrain the surrounding air and move it through the unit away from the vacuum area. While it is able to move a large volume of air, it would not have the same capacity if moving a material of any considerable mass. It creates its vacuum by using a Coanda profile on the ID of the unit. The Coanda profile helps to accelerate the inlet compressed air which enters the unit through a small ring nozzle. This acceleration is what entrains the ambient air from the rear of the unit, and the combined airflow is then directed towards the outlet of the unit.
Based on the above comaprison, for this customer’s particular request, I suggested he stay with a Line Vac and just move to a smaller size. The small tubing would still fit very well through the ID of a 1/2″ unit, so I recommended a model 6079 Stainless Steel model. This will cut his air consumption approx in half, yet still easily be able to convey the light tubing material over the required distance.