Auraria Higher Education CenterCase Study

John Ismert & Frank Ellis

Auraria Higher Education Center

Facilities Management

Auraria Higher Education Center

• Built in 1976-77• 18 campus buildings• 1,700,000 square feet of

office and classroom space

Auraria Higher Education CenterProject Scenario

• Campus built 20 years ago• Fast-track construction project• All the equipment is beginning to

wear out at once• Energy efficient systems have

progressed a lot in 20 years• Time for some major retrofit work

Auraria Higher Education CenterMain Cooling Plants

• North Classroom Chiller Plant

• P.E. Building Chiller Plant• Plaza Building Chiller

Plant• North Chiller Plant

– serves Science, Arts and Library buildings

• South Chiller Plant– serves Central, West, South,

and Technology buildings

Auraria Higher Education CenterHeating & Hot Water System

• Purchased steam from Public Service Company in Denver for heating

• Hot water generated from heat exchange with steam system

• Typical of late 1970s with escalating gas prices• Studied replacement options but decided to

keep steam system– would have needed 60+ gas boilers– able to negotiate lower steam cost

Auraria Higher Education CenterElectricity Use in North Chiller Plant

• Monthly cooling and non-cooling electricity consumption 1995

• Monthly electricity demand 1995

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Energy Consumption (1000 kWH)

cooling consumption non-cooling consumption

0

100

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1000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Demand (KW)

Auraria Higher Education CenterProject Challenges

• More work than can be done under the budget available

• Must fit into a 10 year self-funded project

• Coordination of systems between all campus buildings

• Need to restore cooling capabilities before the summer of 1997

Auraria Higher Education Center Campus Improvements Made

• New efficient chillers and cooling tower in North Chiller Plant

• New direct digital controls in 7 buildings • Air side improvements in many buildings• Lighting improvements• Fume hood efficiency improvements

Auraria Higher Education CenterNorth Chiller Plant

• Original Chillers– Two 550 ton centrifugal electric chillers– R-12 refrigerant (CFC)– 0.78 kW/ton efficiency

• New Chillers– Two 550 ton centrifugal electric chillers– R-134a refrigerant (HFC)– 0.48 kW/ton efficiency

• Undersized cooling tower replaced– single-cell, induced draft tower

Auraria Higher Education CenterNorth Chiller Plant Energy Savings

Auraria Higher Education Center Direct Digital Controls

• Added to 7 campus buildings• New fiber optic network• More aggressive energy conservation strategies

– tighten chilled water and hot water resets– tighter run times– changed evaporative cooling & chilled water

sequencing

• Monitored water meters for sprinklers & cooling towers for more accurate sewer credit

Auraria Higher Education CenterAir Side Improvements

• Science building– 2 new air handling units – new coils on 4 old air handling units– new VFD drives and motors for supply air fans– replaced variable air volume boxes

• Art building– replaced evaporative cooler media

• PE building– failing heat storage wheel replaced with heat exchanger

Auraria Higher Education CenterLighting Improvements

• High efficiency T-8 lamps• Rapid start electronic ballasts• Compact fluoruescents in place of

incandescents• Exit lamps replaced with long life lamps• 10,682 fixtures modified in 13 buildings• Light levels maintained or improved

Auraria Higher Education CenterFume Hood Improvements

• Over 50 fume hoods retrofitted– North Classroom and Science buildings

• Proximity sensors installed and attached to 2-position dampers– reduce air flow from 100 fpm to 60 fpm at night

or when no one is near the hoods

• Integrated operation of building make-up and exhaust air and fume hood ventilation

Auraria Higher Education CenterEstimated Project Finances

• Other improvements help pay for chiller plant work

Purchase &Installation

Cost

Rebates andCredit

Deductions

AnnualEnergySavings

PaybackPeriod(years)

North Chiller &Cooling Tower

549,700 63,000 rebate35,000 R-12

25,600 17.6

Direct DigitalControls

577,500 --- 49,40020,000 sewer

8.3

Air SideImprovements

74,000 17,000 13,900 4.1

LightingImprovements

590,800 86,000 rebate40,000 ICP

142,000 3.3

Fume Hoods 279,800 9,000 52,400 5.2

Total 2,071,800 250,000 303,300 6.0Service Contract --- --- - 49,300 7.2

Auraria Higher Education CenterFinancing Structure of Project

• Ten year bond from AHEC• $2 million worth of improvements• $175,000 demand side management rebates• $40,000 ICP grant, $35,000 R-12 credit• Annual utility savings of ~ $300,000• 7.2 year overall project payback period with

performance contracting service provided

Auraria Higher Education CenterProject Timeline

Auraria Higher Education CenterProject Results

• Utility savings of about $300,000 annually• Took advantage of DSM rebate programs• More comfortable learning environment• Increased energy awareness level at AHEC• Newer, more efficient state-of-the-art systems• Reduced dependence on CFC’s