Maintaining Relative Humidity Values

[zsadiq]

Hello,
We have a drying process where we have to maintain different values of Relative Humidity values in a day. That is, 80% RH from 0900 hrs to 2000 hrs, 60% RH from 2000 hrs to 2300 hrs and 40% RH from 2300 hrs to 0900 hrs. I'm unable to find a humidity controller that can be programmed in this fashion. Can you please mention some specific product for this purpose.
Thank you.

 

[walkes]

You can use any stand-alone DDC controller to accomplish this. The controller can be programmed to schedule the various humidity set points and times. Manufacturers: Honeywell, Johnson Controls, Alerton, Automated Logic.

 

[zsadiq]

Thanks for your reply walkes. I was actually looking for some stand alone equipment that can handle the above mentioned situation. I've found one "Extended Digital Controller" from Johnson Controls which can be checked at this url.

http://www.johnsoncontrols.com/Metasys/controllers/edc.asp

Can you verify for me that this controller will work? Also, this seems to be an expensive device, so any suggestions for a cheaper solution?
Thanks

 

[cme]

What you want to do is get a points list then select an appropriate controller that has the capability. RH input (AI), mod output (AO), failures, etc. What type humidifier? The mfr is always willing to help to get in the spec.

 

[walkes]

zsadiq,

I was thinking more of something like the unitary controller

http://www.johnsoncontrols.com/Metasys/controllers/unitary.asp

You should contact JCI to determine if that product is suitable for your application.