Sizing of AHU Cooling Coil

I hope this is some help - you have supplied no criteria for the coil - The fan and cooling are designed to meet a load - you seem to have the equipment before you have a known application.

1) AHU capacity:- 12525CFM@125mmWG &

2) Cooling capacity is 58TR.(chilled water system)

if cooling coil velocity is 500fpm.

weather coil should be of 4 row or 6 row?.

THE COOLING COIL HAS RELATION SHIP TO AIRVELOCITY SO THAT THERE IS NO CONDENSATE CARRY OVER AND THE RELATION SHIP IS A SIMPLE CALCULATION.

CFM=12525 AND FACE AREA OF COIL IS CFM/VELOCITY= 12525/500= 25 SQFEET

HENCE THE SIZE CAN BE 5FEET*5FEET = SQUARE COIL( hEIGHT *LENGTH)

2.5FEET* 10FEET = RECTANGULAR COIL ( hEIGHT *LENGTH)

aS REGARDS CAPACITY USE THE FOLLOWING FORMULA

CAPACITY= 1.08*DELTA T(F)* CFM

NOW TR=58 SO IN BTU/H= 58*12000= 696000

SO 696000/12525CFM*1.08=DELTA T (F) =51.4

SO ITS RECOMENDED TO USE 6 OR EVEN 8 ROW COIL TO ACHIEVE THIS LOAD REQUIREMNT

HOPE THE ABOVE IS HELPFUL FOR YOU

REGARDS

RAJESH BALAKRISHNAN

DIRECTOR-ENGINEERING

STULZ-CHSPL (INDIA) PVT LTD

MUMBAI

Rajesh Sir,

Thank you.

This information is sufficient & more helpful to me.

Reagrds

Raju Anagdi

Bangalore

How you concuded for 6 or 8 row coil

HELLO SIR,

COULD YOU PLEASE SEND ME COIL SELECTION AND RELATED DOCUMENTS TO my email

address.*

I WANTED TO LEARN.

THANKS IN ADVANCE

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Sir,Thanks For information ,Pl clarify me for how much temperature difference how many rows of coil to be select.

for Chilled water system & DX System.

Hello RajeshSir,

Can you please show me how you came up with 6 row ? I want to learn.

Thanks

Umang

Dear Sir,

Wouldn't the 'Total Heat Transfer Area' be necessary to determine the number of rows.

Total area would further depend upon the fin spacing, type of fin (wavy or straight), tube pitch (both vertical and horizontal), tube size (3/8", 1/2", etc.).

Since the question was related to the number of rows specifically, above data is necessary with the coil specification, unless these details are standardized.

Moreover, number of circuits will also be necessary to be specified to make the selection complete.

Would like to know your feedback.

Thanks

As the row deep increases the air & cooling coil contact increase reducing the bypass air, obviously the more Row Deep the less is the bypass factor.

CFM/500 will give cross sectional area of the cooling coil. Here it is 25.05 Sqft.

Go for 6RowDeep cooling coil, as 5RD won't be manufactured and also not standard practice for 5RD.

when we use 3,4,6 and 8 row coils?? and their selection??

can you please breif me??

thanks in advance

Hi,

Thanks for your reply. But by increasing the number of rows you are increasing the pressure drop for AHU blower. isn't it?

Amazing