Fan Static Pressure

[lumbee]

NEW HVAC DESIGNER WITH A LOT OF QUESTIONS

Don't manufacturers rate fans according to static pressure instead of total pressure?

Also to get the system static pressure don't you calculate the total pressure for the supply and return and subtract the velocity pressure at the fan outlet?

What are the key items(equipment schedules,codes etc.) that need to be on the hvac plan?

Robby Locklear
Email: robb1@bellsouth.net

 

[ChasBean1]

1. Yes. But trying not to add confusion, it's "total static pressure." Simply put, it's the difference between fan outlet and fan inlet pressures, with no account for velocity.

2. Too complex. "Total system static" probably refers to the pressure loss from all inline components at design maximum flow. It also could mean the pressure in the duct at the sensor's location that will be needed to control fan speed to maintain design flow.

3. Schedules indicating all key design parameters. Drawings of the system showing duct sizes and locations superimposed on a basic archtectural drawing, coordinated with a ceiling plan. Dampers, terminal boxes, humidifiers, filters, control devices, etc. Not codes. The drawings should account for the code requirements and you (the designer) are responsible for meeting them.

Hopefully you have some guidance (?)