ATLANTIC CITY, N.J. --Extraordinary incidents, whether caused by war, terrorism, accident or natural disaster, focus attention on such basic, immediate, human needs as survival and safety and longer-term needs such as water, food and shelter.
Even with such major distractions as the ocean-view boardwalk and casino gambling, the events of September 11 are never far from our minds. And building owners continue to grapple with issues of safety and security. ASHRAE at its annual Winter Meeting in January presented a report on ?health and safety under extraordinary incidents? via a presidential study group.
While no one wants to dwell on the negative, it is imperative that steps are taken to use a building?s inherent mechanical systems to combat the possibility of terrorism. ASHRAE has undertaken a pivotal role, in part to correct some misinformation and actions that could cause as much new pain and harm. It has been reported that some building owners, for instance, are blocking off first-floor air intakes to prevent sabotage by the introduction of pathogens.
The roles of proper ventilation and hvac system operation are important. If all ventilation system components are working properly, the supply of outdoor air will help dilute any airborne contaminants inside the building. Salient points in building operations include:
Verify that filter efficiency has been upgraded to the highest Minimum Efficiency Reporting Value (MERV) attainable under existing conditions of space and available airflow capacity.
Sensors, monitors and other means of forewarning are not presently available or are not reliable for many contaminants. Therefore, strategies other than feedback control are relied upon today.
Physical and air pressure barriers can be employed to reduce the movement of contaminants from these contaminated spaces to other areas of the building.
Fire detection systems should be verified for proper shut down of ventilation fans in the affected zone, but not in the entire building.
Verify that the building shell and air ducts are as air tight as practical.
In addition, there was advice on what NOT to do:
- Do not close outdoor air intake dampers or otherwise block ventilation air paths.
- Do not change the desired airflow patterns or quantities.
Above all, building owners and operators should become familiar with the mechanical and safety systems. Filtration and IAQ guru Barney Burroughs calls this ?Management by walking around.? There will be, he said, increasing responsibilities for building owners, operators, and maintenance providers.
It doesn?t end there. The current study group will continue and is authorized to expand or contract its charge as conditions dictate.
More meeting newsIn other announcements at the show, ASHRAE has released a new publication with practical advice on minimizing the costs and maximizing the benefits of humidity control in commercial buildings.
The Humidity Control Design Guide for Commercial and Institutional Buildings, published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, problems related to excess moisture.
Specific advice in the book includes:
- Installing a separate ventilation system to dry or humidify the incoming ventilation air.
- Calculating the moisture load separately from the sensible heat load.
- Sealing all ductwork, air handlers and duct connections tightly.
- Never oversizing the cooling equipment.
Cost of the book is $120; $78 introductory price for ASHRAE members.
Also, new requirements to ensure that the ventilation system design is implemented in buildings and then functions throughout the life of buildings have been included in ASHRAE’s 62-2001 ventilation standard.
Ventilation for Acceptable Indoor Air Quality sets minimum ventilation rates and other requirements for commercial and institutional buildings. The 2001 standard incorporates the 1999 standard as well as seven new addenda.
Addendum 62.1 adds a new section on construction and ventilation system start-up, recognizing that acceptable IAQ is impacted by more than just the design of the hvac system.
Addendum 62m creates a new section on operation and maintenance procedures. Addendum 62j replaces the current requirement for natural ventilation systems with a prescriptive requirement that is similar to the requirements in many model building codes.