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avaleri
13-04-2012, 11:06 AM
I found this site to be informative & I see that you can help me to understand more in refrigeration.

As I came to a site in search for solutions to improve the cooling capacity of our sytem, I find the website about the evaporative fogging system. May I know if this actually helps increase the peak cooling capacity of the refrigeration system?

...as my friends call me "Tongtong"

aramis
13-04-2012, 07:27 PM
It could help if you have low ambient relative humidity and have plenty of cheap (soft) water.

You should read older threads on the subject in this forum, look for "water spray cooling" or "air cooled/water cooled" systems, etc.

avaleri
16-04-2012, 03:24 AM
Thanks Aramis

I think ,here in Malaysia, has relatively low humidity as other asian country. Our existing air cooled condenser uses sprayed water as interim action (for 2years...wow). Now, its has accumulates dirts & moss all over the fins. We are trying to declogg (manually & using chemicals) the air passage but not enough. We are trying to save other condensers using other aternative condenser cooling. As for now, we cannot replace the chillers immediately so we need to find ways to put it back in action. Cooling capacity of the chillers greatly reduce & affects our process as we have encountered a lot of high discharge pressure alarm.

Any suggestion in this forum is very much welcome.

aramis
16-04-2012, 08:57 PM
Then you should either reduce the amount of water you are spraying or improve the nozzles’ efficiency or spray further away from the fins or use it only during low humidity hours.

The idea is that water evaporates completely before touching the fins.

What you gain is dropping the air temperature form dry bulb to wet bulb. This makes no sense neither if your climate is humid nor if you use the system during high relative humidity hours.

Other problems are if the discharge air of the condenser may hit surfaces below dew point of the discharged air. In this case you need to treat these surfaces against moss and mildew.

If your condensers are too small so that you need to wet the finned surface then you will always face the same problems you are having and the only solution is to change to a larger condenser.

You can improve filtering the air before spraying to prevent dirt but this would bring other problems like fans that can cope with the increased pressure form the filter and larger working area, more maintenance for the filters, adequate filters, etc.

No easy "patch" solution for the dirt but the problem should reduce if you evaporate all the water first.

Magoo
17-04-2012, 03:13 AM
Low humidity in Malaysia, wrong. You live in the steamyist place on the planet during the what ever wet season. Last time in the area I broke into a sweat combing my little bit of hair.

engrp
19-04-2012, 09:12 AM
was also a bit confused when our friend from malaysia said they have low humidity. i think our ambient condition here in the philippines, is identical with malaysia. we usually have an rh of 65 to almost 73 %

aramis
19-04-2012, 04:07 PM
I wouldn't evaporate water to cool unless relative humidity is low.

At 65% to 73% could be, but it also depends on the number of hours/year you have these conditions and correlation with your cooling demand.

I guess it won't be easy to get rid of the moss though!

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