×
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

Raised access flooring

Raised access flooring

Raised access flooring

(OP)
I am conducting several tests for a 40,000 sq.ft medical facility with a raised floor.
While I was not on site every day, I did observe all trades take particular care with sealing all below floor cavities with sealant, including electrical conduit which passes through the floor.
I do expect some leakage.
I have measured approximately .005 thru .015 'wc in a numnber of areas. Does this suggest good sealing in some areas but not others.

I am measuring airflows this week so will be able to compare sum of diffusres to air measured at the air handler.

Is there a standard test for these floors?

thank you,

Tom

RE: Raised access flooring

I don't think you will ever expect the room/floor interface to be well sealed.  It depends on whether it is designed as an access floor or a plenum for underfloor ac.  An access floor will leak up to 25% but still hold a 0.3" differential.  Carpeted, seam sealed UFAD raised flooring would be a different matter and I don't have numbers.

RE: Raised access flooring

I've dealt with a few 100,000 SF of raised floor UFAD systems - generally pressurized floors for both UFAD and Displacement Ventilation systems.  Policing up all the floor plenum sealing is good, and make sure the exposed concrete is sealed with a low/no VOC sealer.

Most of the leakage I've encountered, after a sealed floor plenum is done, are the field-cut floor panels around columns and other places like full height acoustic walls and firewalls - those will be a hard thing to get done right.

Depending on the floor tile manufacturer, the panel to panel sealing can be an issue - I've seen some folks use duct tape to seal the panel to panel edges before the finished flooring material goes down.  But then that sort of reduces the whole "accessible floor" service access doesn't it?

Locally, the feedback I've had from operators of general office buildings where the UFAD raised access floors have been used is that they are so tight and jammed with ducts, pipes, and cable trays, that the IT and Comms people hate them because the access and ease of dealing with services churn rate is worse than the usual dropped ceiling plenum.  Trying to run new services in the raised floor while dealing with support posts every 24" on centre can be a pain.

RE: Raised access flooring

(OP)
thanks for the input

I am finding the hard to fit interfaces is where UFAD leaks the most.
It was a bit of a chore policing the work, but it did get done reasonably well.
I was actually surprised when the engineer was very non-chalant about the sealing...maybe his fan is too large.

I will know by the end of the week and send more info..

Tom

RE: Raised access flooring

Air tightness between the conditioned space and the floor plenum is not very critical as the air is leaking into the space which it is supposed to serve.But they need to be reasonably tight as leaks may need to a "hissing" type noise generation.

However air tightness of the floor plenum on the remaining five sides which may border non conditioned spaces is very critical.Any penetrations,crevices etc on these sides would need rigourous treatment.

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