VAV BOXES WITH PACKAGE UNITS
VAV BOXES WITH PACKAGE UNITS
(OP)
I came across a project where a building was supplied with roof top package unit. Also there were VAV boxes used for different zones. I want to know whether the VAV boxes can be used with Package units or not/. As per my knowledge there will be no Variable Frequency drive in package units...Please Help...





RE: VAV BOXES WITH PACKAGE UNITS
If you do add a VFD to one of these simpler systems, you have to be careful of the means of DX enabling – pressure switches are often used and you might lose cooling (via safety interlock) if the unit modulates to too low a speed. It is likely that your minimum VAV values could not bee too low: maybe 60% of maximum, rather than a typical 25-50%.
For your system, barring any big changes you can probably allow some VAV control (e.g., minimums 60-80% of maximums) but you will have very limited versatility.