Controlling Outside Airflow in VAV Systems
Much has been written about controlling the minimum-outside-air quantity in variable-air-volume (VAV) air-handling systems. However, instead of debating the merits of various control methods, this article will discuss how to apply the mixed-air-plenum pressure method and why it works. ...
Codes & Standards
ASHRAE The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recently announced that Addendum r to ANSI/ASHRAE Standard...
Energy-Recovery Ventilating Units Help Beat Efficiency, Comfort Expectations
Having completed Florida's first Leadership in Energy and Environmental Design for New Construction and Major Renovations (LEED-NC) Gold-certified commercial...
Sustainable Ventilation in High-Rise Office Buildings
Building improvements are straightforward when the owner of a facility also is the occupant. The same cannot be said when, as in the case of many high-rise office buildings, the owner simply is the landlord, with dozens of tenants and spaces in various states and stages of occupancy. When it comes to energy, the tendency is for owners of these structures to charge tenants for all consumption and make no improvements. ...
Multiparameter Demand-Controlled Ventilation
Long known to correlate with human metabolic activity, carbon-dioxide (CO2) levels are a reliable indicator of indoor pollution originating from building...
Ventilation Through Time
The importance of clean air for human respiration was recognized even in ancient Rome. Vitruvius Pollio, the earliest architect whose written records...
Other LEED O&M Points
Following are other opportunities related to ventilation to earn points under Leadership in Energy and Environmental Design (LEED) for Existing Buildings: Operations & Maintenance (O&M)...
Health-Care-Infrastructure Space Planning
Expanding a health-care provider's services invariably requires the modification of an existing structure or the construction of a new one. Because engineers...
Evaluating Airflow-Measuring Devices
Airflow-measurement-device selection is critical to the performance of today's state-of-the-art HVAC control systems, as accuracy and repeatability can...
Regenerative Dual Duct: An Overview
The energy crisis of the 1970s led industry experts and legislators to conclude that buildings needed more insulation, infiltration required additional...
AMCA International Votes Down Scheduled Assessment Increase
The Air Movement and Control Association International Inc. (AMCA International) Board of Directors has reviewed the current dues structure and decided there will be no cap-assessment increase on July 1, 2009....
Large Fans Increase Thermal Comfort, Reduce Energy Costs for University
In remodeling and expanding the Lavin-Bernick Center for University Life (LBC) on its Uptown campus, Tulane University forewent the installation of a traditional HVAC system, opting instead for passive cooling techniques — most noticeably, three 10-ft-diameter fans from Big Ass Fans ...
AMCA International Event Calendar
AMCA International Event Calendar...
Beware of Substitutions
I encountered the installation in Photo A when performing my first punch list as a junior engineer. The mechanical contractor on the project opted to...
Regenerative Dual Duct: A Case Study
Late in the spring of 1998, Dennis Wald had just taken over the position of facilities director for Wausau School District in Wausau, Wis. At one of the district's 21 schools, 27-year-old, 273,000-sq-ft Wausau West High School, two of three boilers were not working; the chiller, an adsorption unit, had failed; classrooms would not heat or cool properly; teachers were threatening a work action; and energy was being used at the rate of 191,562 Btu per square foot per year....
Improving Comfort, Saving Energy With Large Circulator Fans
Although air is not cooled by movement alone, it can create a cooling sensation as it passes over a person's skin. The proper use of air movement, then, can increase occupant satisfaction. It also can improve energy efficiency, as substantial savings can be realized by destratifying heated air in spaces with high ceilings during cooler months. ...
The Blame Game
I need your help on this one, an HVAC technician said. I did a tenant fitup on the seventh floor of an office tower this spring. All I did was ductwork...
Closed-Cell Insulation Quiets Noise Days Before Restaurant's Opening
Less than 48 hours before the scheduled opening of Print Works Bistro, which, along with the adjacent Proximity Hotel, was vying for Leadership in Energy...
Fan Hoods, Demand-Side Ventilation Yield Energy Savings for Restaurant
In most commercial kitchens, exhaust fans run at a constant speed throughout the day, regardless of load. This not only wastes fan energy, it increases...
Fabric Duct Meets Unique Challenges of University of Chicago Lab Building
With most buildings, air distribution is a straightforward mechanical-engineering task. With The University of Chicago's new $200 million, 427,000-sq-ft...
Direct Gas-Fired Air-Handling Units
Direct gas-fired air-handling units (AHUs) have provided efficient, reliable makeup air for many high-exhaust/infiltration industrial applications and...
Updated Standard for Air-Filter Testing
In January, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards committee responsible for reviewing and improving ANSI/ASHRAE Standard 52.2, Method of Testing General Ventilation Air Cleaning Devices for Removal Efficiency by Particle Size, approved two changes to the document's testing and reporting methods, both of which will take effect when the revised standard is published this fall...
UVC Helps Institute Keep Indoor Air, Cooling-Tower Makeup Water Clean
It is well-known that poor indoor-air quality (IAQ) can be harmful to building occupants. In a biotechnology laboratory, it can be detrimental to the integrity of sensitive research and experiments as well. That is why, after opening a new 72,000-sq-ft facility in Newark, Del., in 2001, the University of Delaware's Delaware Biotechnology Institute (DBI) pressure-washed the coils in two 45,000-cfm air-handling units (AHUs) three or four times a year. Still, Robert Pekala, engineering and operations manager for DBI, was not satisfied. ...
Measuring IAQ Parameters
Buildings are not created to use energy, but to provide healthy and productive indoor environments. However, efforts to save energy may cause a reduction in health and productivity by degrading indoor-air quality (IAQ). Therefore, maintaining buildings that provide healthy and productive indoor environments requires testing and measuring of key IAQ parameters. As often is said, if you do not measure energy, you cannot manage it — the same is true for ventilation performance. ...
VAV-box selection
I found Edward Liwerant's article on variable-air-volume- (VAV-) box selection in the February issue (VAV-Box Selection, Code Conformance) very useful...
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