Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
1

is it possible to acheave 100% relative humidity at the outlet of an evaporative cooler by precooling the air about 2 or 3 degrees?

asked 2017-05-17 07:51:25 -0500

amirrezaheydari's avatar

updated 2017-05-17 12:06:18 -0500

is it possible to acheave 100% relative humidity at the outlet of an evaporative cooler by precooling the air about 2 or 3 degrees?

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
1

answered 2017-05-18 11:47:47 -0500

Ricardo GAllegos's avatar

Even if you do not precool,you would need a 100% efficient device.

edit flag offensive delete link more

Comments

Dear Sir Thank you for your answer, but it is not obvious for me. Do you mean that using an evaportative pad alone, I need a 100% efficient pad, but by precooling I can achieve 100% relative humidity? Thank you

amirrezaheydari's avatar amirrezaheydari  ( 2017-05-19 02:59:26 -0500 )edit

The efficiency of an evaporative cooler is by definition ; e= (tdi - tdo) / (tdi - twi)

tdi= Dry bulb temperature at inlet

tdo = Dry Bulb tempeature at outlet

twi= Wet bulb temperaature at inlet.

The minimum outlet temperature would be twi, and at that point you have 100% saturation. But at the same time, it implies that e=1 (100%) So if you precool, you lower tdi, but only if tdo=twi you can have 100% saturation, and 100 % efficiency, which is not posible. In a pshychrometric chart, you will have two paralel lines, but none touches to the saturation curve.

Ricardo GAllegos's avatar Ricardo GAllegos  ( 2017-05-19 13:48:32 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Careers

Question Tools

1 follower

Stats

Asked: 2017-05-17 07:51:25 -0500

Seen: 236 times

Last updated: May 18 '17