Technology Assessment Division

Energy Efficient Measures Taken in State Capitol Complex Building Construction

Overview

The Louisiana Department of Natural Resources (LDNR ) worked with the Louisiana Division of Administration's Office of Facility Planning and Control for four years evaluating proposed energy conservation measures in the new LaSalle, Claiborne and Galvez buildings. The DOE 2.2 building simulation program was used to identify the most cost-effective upgrades to the original building plans. The LDNR and the US Department of Energy (U.S.DOE) agreed to invest $16,032,000 in the design and installation of energy conservation measures in the new buildings. This amount is equivalent to the energy conserved over 25 years above ASHRAE 90.1-1989 minimum design criteria.

Included Energy Efficiency Upgrades

Building envelope measures:

Added envelope mass from base case spandrel glass to heavy weight precast concrete, changed walls and roof from medium dark to light color to reduce solar absorption, used 10 inch window set back for shading, upgraded the window glass to low "e" insulated glass to reduce heat transmission, increased insulation in the walls and roof. Building interior measures: utilized a computer controlled lighting system incorporating reduced lighting density in the general space with task lighting at work stations, increased lighting efficiency by using variable electronic ballast with T-8 lamps with occupancy sensors, perimeter office lights have sensor controlled "daylighting" from 80% down to 10% of lighting power, used mini-blinds for exterior windows.

Mechanical system improvements:

Regulated outside make-up air control by interior CO2 sensors to maintain safe and healthy interior air quality, energy recovered from exhaust ventilation air, higher efficiency central chiller plant used to cool the office space, all pumps and fans are variable speed to optimize energy use.

Outcomes

LaSalle Building

An incremental investment of $2,266,000 in energy conservation measures over the ASHRAE 90.1-1989 specifications gives a projected savings of $4,800,000 over the next 25 years, a 41% improvement in energy consumption.

Claiborne Building

Louisiana invested $4,002,000 in the design and installation energy conservation measures in this new building to save $6,139,000 of energy in 25 years over ASHRAE 90.1-1989 design criteria. This is also a 41% improvement in energy consumption.

Galvez Building

The Galvez Building, new home of the Department of Environmental Quality, represents the cusp of the learning curve for this group of buildings in the Capitol Complex. For an incremental investment of $1,148,000 in energy conservation measures over standard specifications, a savings of $5,093,000 is projected over the next 25 years, a 36% reduction in energy consumption.

Implemented Upgrades

Energy efficiency upgrades to the building are shown in the table below: