All central vacuum systems are rated for a number of “users”. Dental vacuum manufacturers all agree that a “user” equates to a single open HVE valve. Generally, this means an active operative dentist = 1 user and an active hygienist = ½ user (as a hygienist is normally only using the saliva ejector).
With 2 HVEs and 3 SEs, you'll have 3 1/2 "users"
Note that if you also use any of the plethora of other items on the market which attach to your vacuum, these will impact your user levels as well. Such things as the wide range of aerosol reducing devices, the various isolation devices that attach to vacuum, or a scavenger for your nitrous analgesia system will all impact your vacuum. To determine if any of these count as a “user” or not, just consider what it is attached to. If attached to a saliva ejector valve, it likely only counts as ½ user, if it attaches to a HVE valve, it counts as one full user. If it is self-contained, then it will not count as a user at all.
If you have additions to your vacuum system for the various aerosol reduction devices (although, see my previous post on that topic), you may need to re-evaluate your vacuum system as you may need more users than ever. Such additions are taxing central vacuum's capabilities more than ever. We help subscribers decide if an equipment purchase is warranted or not, and what may best fit their needs.