Office tower reduces operating costs with two-stage evaporative cooling system

Journal Article · Wed Mar 01 04:00:00 EST 1995 · ASHRAE Journal

OSTI ID:51727

Colvin, T D ^[1]

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1. Colvin Engineering Associates Inc., Salt Lake City, UT (United States)

Indoor air quality and energy efficiency were the primary objectives during the design phase for the mechanical systems of the One Utah Center. The 24-story, 419,000 ft{sup 2} (38,925 m{sup 2}) office tower in downtown Salt Lake City was completed in 1991 and was 97 % occupied by late 1993. The building has exhibited exceptional energy efficiency in its mechanical system through the use of evaporative cooling, variable speed pumping and thermal storage. The mechanical system utilizes an indirect evaporative/chilled water/direct evaporative cooling system that furnishes over 80 % of the building`s annual cooling requirements without the use of mechanical refrigeration. The system provides 100 % outside air to the building whenever the outside temperature is above 53 F (12 C). Because the discharge air temperature is maintained at 53 F (12 C), the absolute humidity of the supply air is identical to a conventional chilled water system. An analysis of makeup air requirements and annual operating hours versus outdoor wet bulb temperature data can show a viable payback period for this system in many locations and applications. Because the system uses 100% outside air during all cooling hours, buildings requiring large amounts of makeup air have experienced exceptionally low power costs. The two-stage evaporative/chilled water system demonstrated here provides improved indoor air quality and economical cooling even in areas with low power costs.

• OSTI ID: 51727
• Journal Information: ASHRAE Journal, Journal Name: ASHRAE Journal Journal Issue: 3 Vol. 37; ISSN ASHRAA; ISSN 0001-2491
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
COOLING SYSTEMS
EVAPORATIVE COOLING
OFFICE BUILDINGS
OPERATING COST
SPACE HVAC SYSTEMS