For small to mid sized shops, I'd stick a Honeywell TrueSteam on any HVAC in a room over 1,500 sq. ft. Going on the heavy duty size of residential has worked out great for us and it's a fraction of the cost of industrial. Stick to quality brands like Honeywell and stick to a steam version over evaporative for better efficiency and less water usage. These units easily attach directly to the duct work, but you do need to be handy in order to wire a Honeywell thermostat that runs this and the HVAC. The correct settings will turn the HVAC fan on when there is a call for humidification. Plumb your R/O system directly into it for fewer headaches. We clean our units at the beginning and end of the seasons and have had no issues for many years. I cannot say if there's more advanced units that have come out in the last 4 years or so as I have not researched it since puchasing these units.