High Performing Buildings - Winter 2009 - (Page 44)

Lessons LeArned Lighting The attractive oculus in the main lobby uses incandescent downlighting as part of the original design. The downside is that the lamps are challenging to replace when they burn out due to their height above the main floor. A different lighting technology that features long-lasting energy efficient lamps would have made more sense. To work around this issue, we coordinate group re-lamping with tasks that require lifts such as window and metal refinishing activities to reduce the cost of multiple lift rentals. in the future we hope to develop a fixture replacement strategy that incorporates the design intent with long-lasting, energyefficient lighting fixtures. equipment Access The central plant piping is supported by many pipe stands and has control wiring run along the floor. This contributes to a congested work area, which makes chiller repairs more time consuming. A better solution would have been to design piping support that was suspended from the ceiling, and route the conduits overhead to provide free space to move dollies, carts, and technicians throughout the plant freely. equipment location also needs consideration during the construction phase. several air-handling units placed in the mechanical room require maintenance staff to leave the room and enter through another door to gain access to other side of the AHu to perform preventive maintenance. easy access helps ensure that the equipment is properly maintained in a time-efficient manner. relocating the AHu 2 ft in one direction within the room would have resolved this issue. Variable speed drives Two of the three cooling towers were not originally equipped with variable speed drives for the motors. since motor horse power has a cube relationship with fan speed the energy savings would be enhanced. 5 Houston Center plans to install Vfds on the remaining two cells, and incorporate their operation into the control scheme. retrocommissioning This will play an important role in the near term to ensure that systems are operating at peak design. This includes simple steps, several of which have been taken recently, such as auditing HVAC schedules to ensure that lease requirements are met, but also making sure that no rogue schedules have been left in place. We all know that even the most efficient machine running when it is not needed wastes energy. We have audited schedules and adjusted where needed to bring the schedules in line with lease requirements. education inadequate education often derails maintenance teams. examples include adjusting airflow dampers to correct a programming issue; improperly entering an overtime air schedule so that it isn’t automatically deleted after an event; installing a toilet flush valve repair kit (1.6 gallons per flush) in a urinal that is designed for a 1 gallon per flush kit. maintenance personnel need to ask more questions when a temperature complaint occurs: is a draft the problem? When does the problem occur? does the problem occur with the office door open or closed (indicating a return air problem)? Also, verify that the temperature sensor is the one that should be in the space. Conclusions The many design features of 5 Houston Center working in concert with each other contribute to a decreased electricity consumption of 8% when compared to similar properties in a sampling of 150 buildings in the Houston and Dallas markets prepared by our energy consultant Summit Energy Services. This equates to 20 cents per square foot savings. With today’s soaring energy prices, we must constantly raise the bar when looking for opportunities to further reduce energy usage. This includes embracing new technologies as they emerge, and using the existing building enhancements to their fullest extent. Also, it is critical 44 HigH that we include partnering with our tenants to provide them with energy awareness information that they can distribute to their employees. Our employees, vendors and corporate initiatives play an important role as we partner with our resources to not only maintain the energy conservation we have achieved, but to build upon the solid foundation that 5 Houston Center has already established. Our near-term plans call for further reducing energy consumption by retrofitting the two remaining cooling tower cells with variable frequency drives and modifying the outside air intake system to monitor CO2 levels to optimize Winter 2009 the fresh air delivery to the building’s occupants based on ASHRAE standards. We anticipate these two items will reduce annual electrical expenses by approximately $50,000, or an additional 4% of our energy expenditure. • About the Author lubie martin ii is operations manager with Wells real estate funds. He has more than 25 years of experience in commercial real estate, and holds a Texas air conditioning contractors’ license, Bomi’s systems maintenance Administrator® designation, and an associate degree in HVAC&r. Performing Buildings

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

High Performing Buildings - Winter 2009
Contents
Commentary
OHSU Center for Health & Healing
Documenting Performance
Cook+Fox Architects Office
5 Houston Center
Skanska's Atlanta Office
Advertisers Index

High Performing Buildings - Winter 2009