Method to determine if an isolated Unit Ventilator is receiving enough gpm

[Quest73]

Question:

How do you determine if an isolated (read: furthest) unit ventilator is receiving enough GPM from a pump? Background Discussion: During a pump house relocation a new pump and (4) Unit ventilators are re-routed and re-circuited however the one unit ventilator was forgotten back at its original location. New piping was added to capture it at its old location but the distance to make-up from the feed pump house was increased substantially.

Specifics:
Unit Ventilators: 1-3; single row/(750cfm)(125 OA) Total Capacity 32,800 BTUH/Sensible BTUH 20,960/GPM: 6.68/Fluid Coil PD in ft h20: 9.08
Unit Ventilator: 4; single row/(750cfm)(250 OA) Total Capacity 36,302 BTUH/Sensible BTUH 23,385/GPM: 2.9/Fluid Coil PD in ft h20: 11.03
Forgotten Ventilator - unknown but comparable to 1-3 above {all connections are 1 1/2"}

Pump Frame mounted end suction pump / 583 GPM/85 ft of head/1760 rpm/20 HP - suction line 4" / discharge 3"

Thinking: scale distance of piping and measure against ft of head on pump for gpm?

 

[EnergyProfessional]

put in pressure taps and measure pressure drop. From the manufacturer you can find out what flowrate you have with the pressure drop.
you also need to know what your target flowrate is. a unitheater ca be operated in all kinds of flow, it just depends what heat output you need or it was designed for.

What is the dT and EWT for those? It seems a lot of flow and pressure drop for such small heat output.

anyway, all a function of the unit, so the manufacturer is needed.