What’s the purpose of a fan schedule? If a fan is attached to a VFD, should the schedule show the full range (min-max) airflows which the fan can deliver? Along these lines, what’s the point of a schedule for registers, vents, etc.? - Jinx
A fan schedule lists the type and performance specification of the fans required for a project. A vendor and model number for the fan is usualy included, but not always. It’s used to make sure the proper fans are installed. Electrical data is usually included so the electrical contractor can coordinate.
In my experience, a fan that is to be used with a VFD is usually spec’ed at it’s maximum airflow/pressure. You could show the full range if you wanted to. Depends on what the application is, I suppose.
Register, vent, diffuser, expansion tank, pump, etc. schedules are all used to list the type and details of the equipment to be installed. It’s common to create a schedule and put in on a few pages of the plans rather than to have this information placed throughout the plans.
My method is to put only the max capacities on the fan schedule. The full range would go into the sequence of control specification. I do this to prevent errors in duplicating information in more than one place in the specifications
ScoobyTX, P.E.
I couldn’t think of a specific example, but I suppose there could be applications where part load conditions could be important enough to specify. I.e., you want to be sure fan curve and the system curve are at specific values over the entire operating range. I’ve never seen it though. Max capacity is good enough for HVAC.
That’s a good point. I think that anyone who develops plans for projects really should see a few through all the way to completion. One of the first things that you learn is that the guy in the field with the hammer is working off an incomplete set of drawings (that is, if he works for the mechanical subcontractor, he doesn’t have the civil or electrical drawings) that have probably been reduce to half size, has never seen the specifications, and wasn’t involved in the submittal process. Sometimes it’s better than that, but at the very least he has seen the drawings. Making sure your drawings are as complete and clear as possible is perhaps the greatest thing you can do to make the construction as smooth as possible.
I was only briefly in the field and it’s been a while but I remember the the EE’s really need the information on the schedules to calculate how much juice that they needed to supply. It was always the sparkies that were bugging me to finish the schedules.
Haj
I can’t think of an example either- and I’ve spec’d quite a few VFDs for several different types of fans.
On second thought, I can think of a few ways to screw up the design of the control system that would cause problems- most having to do with a poor choice of contol input.