Designing labs, research buildings: Codes and standards

Labs and research facilities house sensitive equipment and must maintain very rigid standards. Codes and standards must be adhered to, with special attention to codes unique to these buildings.

05/28/2013


Nedzib Biberic, PE, LEED BD+C, Mechanical Engineer, PAE Consulting Engineers, Portland, Ore. Courtesy: PAE Consulting EngineersMichael Chow, PE, CxA, LEED AP BD+C, Member/Owner, Metro CD Engineering LLC, Powell, Ohio. Courtesy: Metro CD EngineeringDavid S. Crutchfield, PE, LEED AP, Division Manager, RMF Engineering, Baltimore. Courtesy: RMF EngineeringDave Linamen, PE, LEED AP, CEM, Vice President, Stantec, Edmonton, Alberta. Courtesy: StantecJay Ramirez, Senior Vice President, ESD Global, Chicago. Courtesy: ESD Global

Participants:

Nedzib Biberic, PE, LEED BD+C, Mechanical Engineer, PAE Consulting Engineers, Portland, Ore. 

Michael Chow, PE, CxA, LEED AP BD+C, Member/Owner, Metro CD Engineering LLC, Powell, Ohio 

David S. Crutchfield, PE, LEED AP, Division Manager, RMF Engineering, Baltimore

Dave Linamen, PE, LEED AP, CEM, Vice President, Stantec, Edmonton, Alberta

Jay Ramirez, Senior Vice President, ESD Global, Chicago 


CSE: What challenges do you have when implementing NFPA 45: Standard on Fire Protection for Laboratories Using Chemicals?

Crutchfield: The biggest challenge we face is how to ensure differential pressures are appropriately maintained per NFPA 45 8.2.5 and 8.4.7 when the air handling and exhaust systems go into emergency modes. We’ve seen that when the lab supply fans trip in response to an alarm event, and the exhaust fans remain operational to ensure hood containment, the resulting pressurization differentials can be beyond ADA Door Opening Force Regulations (Title III Section 4.13.11) of 5 lbf. The obvious way to decrease the pressure differential is to provide for a relief pathway, but often that pathway would compromise the fire/smoke barriers surrounding the labs. Opening big holes in your architects’ carefully created fire/smoke barriers is not a good idea when there is a fire in the building. To overcome this, we’ve used transfer systems that actually open in response to an alarm event, which decreases the pressure differential between the lab and the adjacent spaces. To maintain occupant safety in this event, these openings also have local sensing elements that close the opening if products of combustion are detected. An alternative is to provide this pressure relief system such that it directly communicates with the outdoors. However, we have found that when using a direct connection to the outside in areas with coastal air (salt/wet), the dampers and sensors in the transfer system need excessive maintenance to ensure proper operation. Often during testing of these exterior coupled systems, they fail to open due to corrosion, insect nests, etc. This leads to the desire to keep the transfer equipment in a conditioned space. On this issue, we generally confer with the local authority having jurisdiction (AHJ) so that our design meets its criteria for life safety, compliance with NFPA, and compliance with ADA.

Linamen: NFPA 45 has paragraphs that require lab supply and exhaust air systems to be designed in such a way that they prevent pressures that would inhibit egress in the event either the supply or exhaust systems fail. This requires that the operation of both systems be monitored closely, and that the proper control functions be provided to adjust one system appropriately if the other fails so that excessive pressures in occupied spaces do not result. On one of our projects, the building officials actually placed both the supply and exhaust air systems in failure mode separately, and then measured the force required to open doors throughout the building, testing the controls we had provided to prevent excessive pressures in the event of an air system failure. NFPA 45 also prohibits fire dampers in fume hood exhaust systems. We usually address this on a case-by-case basis with the AHJ. Some officials require that the main exhaust duct from each floor extend all the way to the penthouse or roof in a separate fire-rated shaft, since a fire damper cannot be provided at the shaft penetration. Some will accept the sub-duct arrangement from NFPA 90A, where the horizontal main exhaust duct from each floor elbows vertically for 22-in. before connecting with the exhaust riser.

NFPA 45 also restricts the use of ductless fume hoods with absorptive filters that recirculate air to the occupied space to nuisance vapors that do not present flammable of toxicity issues. The ductless fume hood is an attractive lower overall cost alternative for many renovation applications, and this limitation helps prevent users from using the hoods in applications for which they are not intended. Finally, NFPA 45A is used to specify a given minimum flow rate of 25 cfm/sq ft of fume hood internal footprint. The latest 2011 version refers to the ANSI/AHIA Z9.5 Laboratory Ventilation standard, which limits the minimum fume hood flow rate to 150 hood ACH. This translates to a lower minimum airflow in general through hoods, and could cause issues with concentration of flammable or explosive vapors in hood exhaust if a chemical spill should occur in a hood at minimum airflow.

CSE: Which aspect of codes and standards has in your experience provided the biggest challenges or obstacles?

Linamen: NFPA 45, which prohibits fire dampers in fume hood exhaust systems and references ANSI/AIHA Z9.5 for minimum hood airflow, as well as NFPA 90A, which requires duct risers conveying environmental (supply) air from being located in the same shafts as duct risers conveying non-flammable corrosive fumes and vapors. Frequently, it is difficult to provide separate shafts for supply and exhaust air risers.

Crutchfield: NFPA 45 8.10.3.1 provides a challenge in multistory buildings. The separate exhaust shafts required for each laboratory unit, and the need to maintain the fire rating of the building, often mean that multiple sub-shafts are required in the main building shafts. This ensures that the exhaust ducts are compliant with code and also maintain the required fire separation integrity of the building. The challenge is how to build these sub-shaft assemblies in existing buildings. 



No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.