Houston reaps benefits of energy-efficient equipment

The city of Houston recently implemented a number of energy conservation measures including replacing existing HVAC equipment, making central plant improvements, updating building management systems, retrofitting existing light fixtures, adding lighting controls, and installing new plumbing fixtures.

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In 2009, the city of Houston selected Schneider Electric for a $9.6 million performance contract involving phase one enhancements to seven city buildings that delivered annual energy savings of 28%. The second phase aims for Houston to realize 34% in energy savings for each year of the 15-year contract. Together, the city of Houston and Schneider Electric then turned to HTS Texas, an HVAC equipment manufacturer, to provide energy-efficient HVAC expertise and equipment for seven of the buildings.

The HVAC options were first evaluated for their ability to effectively reduce energy consumption in existing buildings. Initially, HTS Texas and Schneider Electric engineers considered whether to install standard centrifugal chillers or magnetic-bearing chillers. Ultimately, the team recommended magnetic-bearing chillers that offered a cost-effective, sustainable, and energy-efficient option that contributes U.S. Green Building Council LEED rating system points for enhanced refrigerant management and optimized energy efficiency. Magnetic-bearing chillers have an advantage on lifecycle payback analysis through a frictionless design and oil-free refrigeration circuits.

In addition to tight deadlines, safety preservation concerns had to be strictly managed while crews maneuvered large equipment and cranes through the crowded metropolitan landscape and installed equipment in occupied, public buildings—several of which were historically significant.

All solutions were successfully implemented by HTS Texas, Schneider Electric, Rincon Air & Heat Co., Graco, C-Air-Two 290-ton Daikin McQuay water-cooled, magnetic-bearing chillers (WMCs) at City HallS Mechanical, Kilgore Mechanical, and McQuay. The equipment installed across the various city of Houston facilities included:

• Two 290-ton Daikin McQuay WMCs at City Hall Annex
• Eighteen McQuay Air-Handling Units at the 28-story Houston Police Dept. (HPD) headquarters
• One 290-ton Daikin McQuay WMC at HPD’s North Police Station
• Two 290-ton WMCs at HPD’s Southeast Police Station
• Two 170-ton Daikin McQuay WMCs at the 104,000-sq-ft Houston Municipal Court building
• Two single-compressor 500-ton Daikin McQuay WMCs at the Hobby Center for the Performing Arts.

Following the first round of downtown projects, HTS Texas partnered with E&C Engineers and Kilgore Mechanical to supply two 250-ton McQuay water-cooled, frictionless chillers, two SEMCO Pinnacle energy-recovery units, and a Daikin VRV system for the 190,000-sq-ft Central Permitting Center downtown. The LEED Gold building, which recently was converted into a multi-office structure from a 100-year-old rice warehouse, serves as a one-stop permitting center for the city and the permanent home of the city’s Green Building Resource Center.

Information provided by HTS Texas.