×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Open Tank Evaporation

Open Tank Evaporation

Open Tank Evaporation

(OP)
What is the resulting RH of air in a warehouse heated to 50-55F with a 35F open tank of water?  

Knowns:
Building is 200x200
Open tank is 100x100
Ambient Outdoor 10F/20%RH
Indoor 50-55F
RH of Air?

RE: Open Tank Evaporation

What is the application or process for the tank?

Is the water kept at 35F, or will it warm to ambient?
Airflow over the tank?

Hypothetically, with no dehumidification (closed system) the wetbulb of the space will eventually hit the temperature of the water.

RE: Open Tank Evaporation

(OP)
The water temps will fluctuate based on groundwater temperatures.  There is little air movement in the space.  

I'm asked to evaluate the insulation properties of the enclosure to determine if condensation will occur.

So, if no outdoor air is introduced you think the Wet bulb of the space will reach the water temp?

RE: Open Tank Evaporation

Basic mass diffusion. My guess in a real world application it won't get necessarily all the way there, but water will continue to evaporate into non-saturated air. I'd design for that scenario   

RE: Open Tank Evaporation

From the Psych chart, Saturation at 35degF will cause a worst case scenario of ~45%RH when heated up to 55degF.  It will never get to this under these conditions.

This problem of yours is highly time dependent and needs to factor infiltration and ventilation to solve.

RE: Open Tank Evaporation

Have you measured the air velocity in the building?
That will influence the heat transfer most. If you have two different temperature heat sinks, you will have air motion.

 

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!


Resources