Parklawn Building Renovation for GSA Tenant

Existing building retrofit: Parklawn Building Renovation for GSA Tenant; GHT Limited

Source: GHT Limited

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Project name: Parklawn Building Renovation for GSA Tenant

Location: Rockville, Md.

Firm name: GHT Limited

Project type, building type: Existing building retrofit, office

Project duration: 5 years

Project completion date: Aug. 29, 2014

Project budget for mechanical, electrical, plumbing, fire protection engineering only: $2.5 million

Engineering challenges

The MEP engineering solution addresses many of these challenges. GHT’s design for an upgraded system, which includes revamped chillers and cooling towers, still allows nearly 75% of the existing building equipment in the mechanical penthouse to be reused. Keeping significant portions of the penthouse equipment online during the renovation will reduce disruptions to tenants in the occupied spaces. It also allows the nonrenovated wing to remain operational with its existing system from the shared penthouse. To help maximize ceiling heights, the design team’s mechanical solution is much more compact and requires smaller infrastructure than the legacy system. GHT used Autodesk Revit MEP, BIM software, in collaboration with Gensler to coordinate the tight plenums required to achieve this goal.

Solutions

To deal with these design constraints, the HVAC design utilized a central water system supplying local water-cooled HVAC units, with air cool units serving the public and food courts. Pump staging and VFDs were used to vary water supply to meet the partial load conditions and provide a more energy-efficient system. In order to deal with the backup power requirements and limited space, the generators were located in the underground areas with exhaust and cooling water systems skillfully routed to the roof level and hidden from view. The supply air is routed underground utilizing a ductwork system powered by a set of in-line fans, and the exhaust air is removed via strategically located air shafts hidden from view and powered by dedicated up-blast fans.