×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

*
*
*
*

Thanks. We have received your request and will respond promptly.

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

Humidification System in Hospitals - How to Interlock

thread403-481371

Humidification System in Hospitals - How to Interlock

Humidification System in Hospitals - How to Interlock

(OP)
The snippet below is from Standard Z317 - Special Requirements for Heating, Ventilation and Air Conditioning in Health Care Facilities



Can anyone provide a definition of what 'interlocked' means? The standard itself does not define it.

I understand that the intent of this interlock is to shut down the humidification system when the air-handling unit supply fan is off, but how must this be achieved? Must I use a physical electrical interlock snap switch and physically wire the fan and humidifier or can I program this requirement into a logic board which shuts off the humidifier when the system notices that the fans are off.

Any guidance on how 'interlock' can be achieved to satisfy this standard would be appreciated.

Thanks!


RE: Humidification System in Hospitals - How to Interlock

Interlocking means exactly what you define it as. whne the fan turns off, the humidifier needs to stop.

They won't accept a pressure switch. I assume this is because a pressure switch may not work reliably in VAV systems with widely varying flows and consequently varying pressure differential when the fan runs. You could use a VFD reading, or have the controller that controls the fan also control the humidifier. the latter may not be reliable if the fan fails. The VFD can read power draw, so above a certain draw you could activate the humidifier.

RE: Humidification System in Hospitals - How to Interlock

You need to hardwire the steam supply with the fan power supply. So if one shuts down, the other one shuts off simultaneously.
Usually this would be done on the control cabinet of the AHU.

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

Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
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