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Cofreth
28-01-2014, 04:04 PM
I have a very old model AHU manufactured by YORK Borg Warner. The name plate of the AHU is missing too.

Is there a general rule of thumb to estimate the cooling capacity by the surface area of the chilled water coil?

Or by blower motor horsepower etc?

Thank you for any input.

frank
28-01-2014, 06:02 PM
If it is working you can find the duty from the flow rate and the delta t

marc5180
28-01-2014, 09:04 PM
Q = m x Cp x p x DT

frank
28-01-2014, 09:16 PM
Can't give you Rep Marc...must spread it around etc lol..

marc5180
28-01-2014, 09:46 PM
Thanks anyway Frank:)

Cofreth
29-01-2014, 02:58 PM
If it is working you can find the duty from the flow rate and the delta t

Chilled water flow rate or Air flow? Delta T of air or water? Tq

frank
29-01-2014, 07:18 PM
Airflow (volume) over the coil, air on temps, air off temps.

Magoo
30-01-2014, 02:41 AM
Delta T DB will give sensible heat capacity, Delta h will give total heat, probably the water test would be easier
Q= water flow rate x DT x 4.2kj/Kg ' C

moideen
30-01-2014, 06:48 AM
for example:

Air quantity =370CFM
Temperature of air entering the coil DB = 78F
" WB = 67F
Temperature of air leaving the coil DB = 59F
" WB = 57F
Enthalpy of air at 67F WB = 31.62 BTU/lb
Enthalpy of air at 57F WB = 24.48 BTU/lb
enthalpy deference = 7.14BTU/lb
capacity = 4.5*370*7.14= 11888 BTU/lb