Green Meets Green in Emerald City

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Since the predominant energy use in the Pacific Northwest is heating, this building was designed to saves energy through reduction of the heating load. This is accomplished with a focus on the two largest sources of heating load: the building envelope and fresh air ventilation.

To reduce heating requirements from fresh air ventilation, the project incorporates demand-controlled ventilation in both high occupancy spaces, and normal office spaces. In the densely occupied spaces, such as the lobby, conference rooms, and council chambers, carbon dioxide sensors are used to precisely measure the amount of pollution in the air and adjust the ventilation levels accordingly. In the regular office spaces, occupancy sensors detect the presence of people and switch the ventilation off or on accordingly.

Heat Recovery, Solar Hot Water System

Other energy efficiency features include the data center heat recovery system, where waste heat from servers is rerouted to office zones when heating is required. This system uses a variable speed fan to extract hot air from the data center and convey it to a handful of VAV terminal units on the north perimeter of the building. A solar hot water system uses a rooftop collector to pre-heat water for the council chambers restrooms.

Parallel VAV boxes are used because of their efficiency in delivering conditioned air to the spaces. In the data center, cooling energy savings are achieved by separating the cool air delivered to the servers from the warm air discharged from them. Plastic curtains keep the two airstreams from mixing, thereby allowing a higher supply air temperature to be used for greater efficiency.

Each piece of equipment was commissioned individually to ensure that it operated as per the design intent. The MacDonald-Miller commissioning team worked side-by-side with a third-party commissioning agent to implement the project's commissioning plan. This written plan leaves no room for error and ensures that the building operates per the engineers' design intent and owner's desires.

“This project's priorities of high value and energy efficiency proved to be a challenge, but also one of the project's greatest successes. As the two priorities are often at odds with each other, striking a balance became necessary,” Sheeks says. “This was accomplished through detailed energy and financial analyses that gave the team an objective ranking of each energy conservation measure. Using accurate total cost data, the analyses gave the team a good idea of the relative value of each measure. The end result was that the owner's budget was spent as efficiently as possible, and money was not wasted on high cost systems that might not be high value, or may not function up to their potential in the Pacific Northwest climate.”

Where else but the Pacific Northwest's “Emerald City” would you expect to find such a peaceful coexistence of green and … green?

Winner at a Glance:

COMPANY:

MacDonald-Miller Facility Solutions, Seattle, WA

PROJECT NAME/LOCATION:

Shoreline City Hall and Civic Center, Shoreline, WA

TOTAL COST:

$2.5 million

PRODUCT KEYS TO SUCCESS:

• 2 Trane IntelliPak II rooftop packaged air conditioning units
• 2 Trane Precedent server room air conditioning units
• 2 Data Air mini ceiling computer room units
• 60 Nailor D35 parallel fan powered terminal units
• Multiple Greenheck exhaust fans, motorized dampers, and fire/smoke dampers
• Siemens TALON controls
• Canariis duplex water booster pump
• A.O. Smith water heaters
• Zurn toilets and urinals
• Toto faucets