Cooling Air temperature Vs. Chilled Water Temperature

[sfxf]

In the project I am working on, the air needs to be cooled from 140 F to 50 Deg. F to serve the specific machine. The heat transfer is through an air-to-water cooling coil. The chilled water is available from a central chiller system and the supply temperature is 44 Deg. F. My question is: Is it feasible to cool the air to 50 Deg. F by only 44 deg. F chilled water? What is the minimum temperature difference between cold air leaving temperature and chilled water supply temperature, for the best performance of the coil?

Thanks in advance for any feedback.

 

[remp]

Im sure it can be done, but your going to need a very, very deep row coil,with a high air side pressure drop. The two temperature are getting very cloes together. Make sure your design leaving Chilled water temperature from the coil is 50 Deg F maximum, other wise you'll never get 50 F air off the coil. Talk to a coils manufacture and they'll sort you out.

 

[Cooky]

The temperature difference (50-44) is 6 deg.F, this will not present any problem for a coil manufacturer to meet.

With a 44 deg.F water temperature, it would be possible to achive approximatly 45 deg.F leaving air temperature, although the coil block would be about 9 rows deep!.

As billyg suggests, talk to a good coil manufacturer.

Cooky

 

[lilliput1]

It can be done but make sure flow is counterflow. The airflow path is opposite the chilled water path so the leving air approched the entering water temperature. Also make sure you do not use more than 10 rows & more than 12 fins per inch so coils may be sray cleaned. Check air and water pressure drops & make sure fan & pumps can handle corresponding flows and pressure drop. Include pressure drop of control valve (at least 5 ft or 50% of the coil water pressure drop whichever is greater).