How to estimate the capacity of a chilled water AHU designed for office comfort
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.
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
If it is working you can find the duty from the flow rate and the delta t
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
Can't give you Rep Marc...must spread it around etc lol..
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
Quote:
Originally Posted by
frank
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
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
Airflow (volume) over the coil, air on temps, air off temps.
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
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
Re: How to estimate the capacity of a chilled water AHU designed for office comfort
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