High Performing Buildings - Summer 2009 - (Page 54)

oak trees as possible on the existing site were left in place. A highly reflective roofing material was used as well as covered parking with the same solar reflective index to further relieve higher temperatures due to the hardscape. F I R S T F L O O R H VAC P L A N HVAC The building is zoned with individual comfort control in mind. The variable-air-volume HVAC system provides enhanced occupancy comfort and takes advantage of thermal diversity within the building to improve part-load operating efficiency. The 60-ton rooftop unit specified by the mechanical designer has the capacity to produce 21,400 cfm and incorporates a maximum of 5,350 cfm of outside air. It also uses a 6 in. thick MERV 13 filter. The unit is designed to use R-407C refrigerant, a hydrofluorocarbon that does not contribute to ozone depletion and contributes little to global warming. Mechanical engineers specified a variable volume air handler with an on-demand ventilation scheme. CO2 sensors and occupancy sensors control ventilation air. Outside air is a major source of energy consumption, but it has a direct positive impact on indoor air quality. The engineers designed the system to provide up to 30% more outside air than required by code and ASHRAE Standard 62.1-2004, but also to regulate the outside air based on occupancy rather than by preprogrammed schedules. A properly controlled building ventilation rate is a key benefit for this building’s indoor air quality and energy efficiency. 54 HIGH PERFORMING BUILDINGS Small mini-split systems improve energy efficiency in less-occupied support areas. The 60-ton rooftop unit produces 21,400 cfm of air and uses R-407C refrigerant, a hydrofluorocarbon that does not contribute to ozone depletion and contributes little to global warming. Summer 2009

Table of Contents for the Digital Edition of High Performing Buildings - Summer 2009

High Performing Buildings - Summer 2009
Contents
Commentary
Jewish Reconstructionist Congregation
Designing Efficient Lighting
CSOB Headquarters, Prague
U.S. Homeland Security, Omaha
Stellar Commercial Building
Advertisers Index

High Performing Buildings - Summer 2009