How to increase a cooling coil capacity?

[digitrex]

I have an old chilled water cooling coil which need to be replace and I am thinking of increasing the capacity slightly. Which of the following choice is better:
1. Increase no. of rows of cooling tubes(present 4 rows)
2. Increase no. of fins (present 12fpi)?

 

[quark]

Presuming you have enough chiller capacity, 12fpi is quite ok and you can go with a 6 or 8 row coil.

 

[AEBuck]

I concur w/ more rows. My personal limit is 10 fpi, which allows a reasonable opportunity for cleaning.

 

[HVAC68]

Another way to increase the capacity.

Q = (4.5) x (cfm) x (Delta H)

Increase the air quantity, if possible, of course within the limits so as to ensure that there's no moisture carry-over and the ducts can take the higher air quantity without creating any noise issues.

HVAC68

 

[lilliput1]

Check the other parts of the AHU also particularly fan mounting. It may be better to replace the entire unit & use variable speed fan along with deeper coil. Check how new AHU can be brought in, in sections or field fabricated in place. You may need to have wall, roof section or louvers taken out and replaced.

 

[Icanfix]

If you play around with the air volume you better check the delta T of the water through the coil. Although that would be one way to increase the cooling from the coil. Increase the air and water flow. Only with increased water flow you will probably still need to increase the transfer rate of the coil.

 

[cme]

I've been specifying a UV lighting system on CHW coils for hospital AHU's.

 

[DRCommisioningEng]

I would also suggest using a contra flow coil. The easiest way to increase the Kw output of the coil is to increase the CHW flow through it.

By how much do you want to increase the capacity?