×
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

air inlet at walls

air inlet at walls

air inlet at walls

(OP)
I have a battery room with 500 L/s exhaust fan. This room is cooled by decorative split unit. The thing is, there is no make up air provided for the exhaust. I cannot put air handlers as there is no space for it within the building / room. Can I just put air inlet (sand trap louver with filter) at the external wall of the room and additional split unit to cool the additional load of the entering hot air? The outside design temp is 50 degC.

RE: air inlet at walls

What is the purpose of the exhaust fan? for actual cooling, or ventilation (battery gas etc.)

if you have lead-acid batteries, NEC and other codes are concerned about hydrogen. Other type of batteris amy have other issues and can explode/combust. so this may require some more thinking than just the air intake.

for batteries, you don't want them to get cold as they lose capacity. Depends on your climate.

You din't provide a lot of information.

RE: air inlet at walls

To add to what EnergyProfessional has stated, if the exhaust fan purpose is to remove air from a battery charging room with lead-acid batteries, then you are dealing with Hydrogen. Check NFPA for required ventilation and sensors. Some possible requirements: XP fan, aluminum ductwork, LEL detectors, high exhaust inlets.

RE: air inlet at walls

(OP)
Yes the exhaust fan is for the hydrogen. My concern is 500 L/s exhaust without makeup air?

RE: air inlet at walls

Mass balance. If you don't have make-up air, the space will be negative and draw air through all the crack from adjacent spaces. that may be what you want since you don't want hydrogen to diffuse int eh building.
At some point the EA fan isn't strong enough and you can't meet your 500 l/s. then you need to create large opening to adjacent spaces, or provide Make-up air.

RE: air inlet at walls

How big is your battery room? 500 L/s is a large quantity of air! Is this according to your local code requirements?

Also 50 deg C ambient conditions is very high! I would consider an air to air heat exchanger to reduce your AC unit load.

RE: air inlet at walls

You should put in a transfer from an adjacent space with a fire/smoke damper in the opening. That way you don't pull in unconditioned air into your room.

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