Advanced HVAC Design Lowers Facility’s Energy Use

The Victor Valley Water District Administrative Facility in Victorville, CA, is a 5090 m^2 building located in the high desert area of Southern California. Because of the arid and generally temperate climate in Southern California, the building was an ideal candidate for an innovative approach that has reduced heating and cooling energy consumption by more than half while avoiding primary use of refrigerant cooling, which contributes to global warming. Evaporative cooling, which is usually used to cool industrial buildings, is seldom used to cool commercial office buildings. However, recent advances in the design of highly efficient evaporative cooling methods by incorporating multi-stages of indirect cooling and direct cooling have made evaporative cooling more cost effective.

These technological advances coupled with Southern California's arid and temperate climate made the Administrative Facility one of the first commercial buildings to use evaporative cooling. The new $1.89 million (USD) building project included not only a new indirect/direct evaporative heating, ventilation, and cooling (HVAC) system, but also new high efficiency lights, dual glazed windows, higher value insulation, occupancy sensors, an energy management system, and other energy conservation and efficiency measures.

To demonstrate an innovative approach that has reduced heating and cooling energy consumption by more than half while avoiding primary use of refrigerant cooling, which contributes to global warming. The building also incorporates other energy efficiency features.

Energy savings have been substantial. Before the project, annual electricity consumption totaled 202,000 kWh. After the project, electricity consumption totaled 104,000 kWh, a saving of 51%. This project received an 'Honorable Mention' from the American Society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE) during its 2000 Technology Awards.

Technical data

The facility's HVAC system consists of a high efficiency indirect/direct cooling unit with a 20-ton Dx refrigeration (R-22) heat pump coil, variable-air-volume zoning, and digital direct controls. The unit provides building heat down to an outdoor temperature of 4.4ºC. A high efficiency gas-fired water boiler is used to provide heating below this temperature. The indirect/direct cooling unit, which is a 20-ton dual compressor heat pump, provides cooling without the use of refrigerant during the peak cooling months of June to September.

Energy data

The baseline used to determine energy savings created by energy conservation and efficiency measures employed in the construction of the Victor Valley Water District Administrative Facility was determined by computer modeling of standard HVAC and other equipment. The baseline annual energy consumption was 202,400 kWh. Actual energy consumption for the first year of occupancy was 103,800 kWh, a savings of 98,600 kWh or 51.3%.

Energy Generated/Saved

355.0000 (GJ/y)

Economic data

A total annual energy savings of 98,600 kWh combined with avoidance of peak demand charges translates to an annual cost savings of $21,485 (USD). These savings were verified by Southern California Edison (SCE), the local power utility. The cost of the indirect/direct evaporative HVAC system was recovered in 1.6 years thanks to a rebate from SCE. Without the rebate, the cost of the system would have been recovered in 2.8 years.

Contacts:

Victor Valley Water District Admin Facility

17185 Yuma Road

Victorville, CA 92393

760-245-6424

760-245-9219 (fax)

http://www.vvwater.org

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