Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Desiccant dehumidification

Desiccant dehumidification

Desiccant dehumidification


Desiccants need regeneration once having absorbed humidity.

My idea is to span the inlet to a ventilation system with sheet desiccant material to remove evening humidity and having that sheet exposed directly to the sun during the day to regenerate the desiccant.

Perhaps the sheet holder can be constructed within a semi solar cooker (mirrored) configuration to speed the process.

For those familiar with the material, would this work?

RE: Desiccant dehumidification

If you are using Silica Gel you would need to get above the boiling point of water to effectively remove the moisture.

RE: Desiccant dehumidification

Thsnk you Berkshire.

I was not aware that it needed to be boiled to evaporate its absorbed moisture. Does it actually and uniformly need to exceed 100C?

Nevertheless certainly a solar cooker configuration ccould achieve that. No?

That kind of heat however would affect the temperature of the ventilation. In cool climates that could be an advantage but in hot a disadvantage. I live in FL USA.
Kind regards,

RE: Desiccant dehumidification

The recommended temperature for regenerating Silica Gel is 100 to 140 degrees celsius. A concentrating type solar cooker can achieve that. The flat plate types have a hard time getting over 70degrees celsius.

 I would suggest a damper and vent to allow the humid air to vent while the desiccant is regenerating.

The other suggestion would be a desiccant wheel running between a hot duct ( regenerative) and your cold duct.

RE: Desiccant dehumidification

Thank you Berkshire this is just what I need.

RE: Desiccant dehumidification

Hello all,

I am an intern at a company called voestalpine Elmsteel in Lafayette, IN.  I am going back to Purdue soon, and am trying to wrap up/implement a few projects before my time is up here.  We are having problems finding a solution to the excess water/cleaner solution vapor being exhausted by our aqueous parts washing machines.  They have a small footprint and exhaust the vapor at a low flow rate (somewhere around 30 CFM I believe), but over the course of the day, they expel 50 gallons of water in addition to about 2 gallons of cleaner into the factory in the form of vapor.  I cannot find a mist collector or desiccant dehumidifier that can extract that amount of liquid from the exhaust, but also run at a flow rate low enough to suit our machines.  In the past, a centrifugal unit was installed with ducts connected to the exhaust vent on top of the machine.  However, the blower ran at too high of a flow rate, and drew about 40 to 50 degrees F of heat from the machine.  For this reason, a lower CFM, high extraction machine is needed, but one that can extract the liquid at temperatures around 150 deg. F.  Does anybody know of a potential solution?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close