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

Journal Article · · ASHRAE Journal
OSTI ID:51727
 [1]
  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, Vol. 37, Issue 3; Other Information: PBD: Mar 1995
Country of Publication:
United States
Language:
English