Coil Flow and Pressure Drop

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Hi everyone,

I am looking for confirmation I understand what eQUEST is doing with inputs
for VAV boxes with HW reheat coils.

On the water side for each. reheat coil, I know design flow, design delta
T, design heat gain and design pressure drop.

Based on the below inputs, I am assuming eQUEST will calculate the design
flow ~ 1.9 GPM; [9,625 Btu/hr / 500 / 10 degF = 1.9 GPM].

[image: Inline image 5]

On the air side, I also know the design flow and delta T. For this
example, it is 270 CFM and 25 degF:

[image: Inline image 4]

Will eQUEST use the max airflow (270 CFM) and subsequently calculate the
max heat gain across the coil (~7,290 Btu/hr); [1.08 * 270 CFM * 25 degF =
7,290 Btu/hr].

If so, does eQUEST adjust the HW flow rate through coil to match this heat
gain (~1.46 GPM); [7,290 Btu/hr / 500 / 10 degF = 1.46 GPM]

Am I correct in how eQUEST is using these inputs?

Also. how does eQUEST calculate the PD through the coils, both on the
water-side and air-side?

Thanks
Darryl

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400