the center for the creative and performing arts high school

The Center for theCreative and Performing Arts

High School

Pittsburgh, PA

CAPAHigh School

Pittsburgh, PA

Andrew Tech Mechanical Option Spring 2003

Presentation Outline

□ Introduction / Background

□ Existing Conditions

□ Mechanical Analysis

□ Lighting Analysis

□ Conclusions &

Final Recommendations

CAPA High School Pittsburgh, PA

Introduction / Background


Architect MacLachlan, Cornelius & Filoni Architects, Inc.

General Contractor Mascaro Construction Company

Mechanical Engineer

Firsching, Marstiller, Rusbarsky & Wolf Engineering, Inc.

Lighting / Electrical Carl J. Long & Associates

Structural Engineer Brace Engineering

Owner Pittsburgh Public Schools

Project TeamIntroduction &

Background


■ Located in Pittsburgh’s Cultural District

■ Magnet School■ 550 – 600 students■ Highly specialized

education in

□ Music□ Theater□ Dance□ Visual Arts □ Literary Arts


Pittsburgh’s Golden Triangle


□ 400 – Seat Theater

□ 6 Story Stage-House

□ Orchestra Pit

□ Stage Craft Shop

□ Old-fashioned Marquee

Architectural Features

□6-story Glass Curtain Wall

□Orchestra / Choral Rehearsal Hall

□Dance Studio

□Black Box Theater

□Green Space


Architecture

□ 175,000 sf – Total□ 133,000 sf – New□ 42,000 sf – Renovation□ $36 million□ June 2001 - August 2003

Mechanical Analysis


Intent of Analysis

Determine Applicability of Cool Tools Optimization Procedure

Cool Tools: Chilled Water Plant Design Guide▫ Chapters 6 & 7

□ Survey of Design Professionals Develop a typical chilled water plant design procedure Determine when Engineers optimize their designs

□ Application of Optimization Procedure□ Comparison of Procedures

Costs Energy Consumption

Mechanical

Analysis

Mechanical Analysis

Typical Design Process

□ Chilled Water distribution system Based upon size of system and past experiences

□ Chilled Water temperatures, flow rates, & pipe sizes Typically 2.4 gpm/ton Use of standard 10ºF ΔT

Q = 500*gpm*ΔT → gpm = Q/(500*ΔT) Pipe Sized using equal friction method


Mechanical Analysis

Typical Design Process

□ Cooling Tower Manufacturer’s Selection Software Speed control

▫ Past Experience

Range – standard 10ºF ΔT (default value) Flow rate – 3 gpm/ton Approach – standard 7ºF (default value)

□ Chiller Selection Determine Load using computer program (HAP, TRACE, etc.) Select number of chillers based on required redundancy Chiller size = Load / number of chillers Manufacturer’s catalogs & vendor recommendations


Mechanical Analysis

Cool Tools’ Optimized Design Procedure

□ Chilled Water distribution system Recommendations based on general rules-of-thumb

□ Chilled Water temperatures, flow rates, & pipe sizes 3-step procedure to determine system ΔT based on

“maxing-out” the flow in pipes▫ First cost optimum▫ Reasonable flexibility▫ Reduces energy costs


Mechanical Analysis

Cool Tools’ Optimized Design Procedure

□ Cooling Tower 3-step procedure to select condenser water temperature range Increase efficiency (gpm/hp) Vary Approach Develop performance Specification and collect bids from

manufacturers

□ Chiller Selection Determine design load using computer program Develop performance Specification and collect bids from

manufacturers Estimate building energy consumption with detailed computer

model Calculate Life-Cycle Cost (LCC) estimate and select chiller

arrangement with lowest LCC


Mechanical Analysis


Cool Tools Optimization Design Procedure

Step - 1 – Select chilled water distribution system flow arrangement.

Step - 2 – Select chilled water temperatures, flow rate, and primary pipe sizes.

Step - 3 – Select tower speed control option, efficiency, condenser water temperature range and approach temperatures. Make preliminary cooling tower selection.

Step - 4 – Select chillers using performance specification & life-cycle analysis.

Step - 5 – Adjust tower sizing and number of cells if necessary.

Step - 6 – Finalize piping system design and select pumps.

Step - 7 – Develop and optimize control sequence.

Application of Optimization Procedure

Mechanical Analysis



Building Load Profile

0

500

1000

1500

2000

2500

10 20 30 40 50 60 70 80 90 100

Percent Load

Ho

urs

per

Yea

r

Design Load▫ Carrier’s Hourly Analysis Program (HAP)

▫ Peak Design Load = 500 tons

▫ Hourly Analysis of Building Load for entire year

Mechanical Analysis

From Table 6-1

Application - 6▫ Many small coils

Primary-Secondary Variable Flow


Step - 1 – Select chilled water distribution system flow arrangement.

Primary-secondary variable flow arrangement


Mechanical Analysis

Step 2.1 – Determine flow rate using a low end of 12 ºF ΔT & a high end of 18 ºF ΔT




Step 2.2 – Pick smallest pipe from Table 6-8 & adjust ΔT to “max-out” pipe size

Step 2.3 – Choose ΔT based on results

Chilled Water Supply Temperature = 44 ºF Chilled Water ΔT = 14 ºF Primary Pipe Size – 8” Main Riser Pipe Size – 6”

Mechanical Analysis

Tower Speed Control▫ Two-speed tower (full/half)

Condenser Water Temperature Range▫ Similar selection method as chilled water ΔT ▫ Actual Result ΔT = 10.8 ºF ▫ Used ΔT = 12 ºF

Approach▫ Limited to 7 ºF

Efficiency▫ Limit size of cooling tower to that of original tower


Step - 3 – Select tower speed control option, efficiency, condenser water temperature range and approach temperatures. Make preliminary cooling tower selection.

Cooling Tower Selections▫ Marley’s Update Selection Software


No Cap EWT LWT EAT°F HP

WB EACH

NC8302E2 2 500 1000 97 85 78 2 10 480-3-60 1.00NC8303DL2 2 500 1000 97 85 78 2 7.5 480-3-60 1.06

°F NO. Voltage

Cooling Tower Selections

Model No. GPM MOTORS Cost Ratio Index

Cells tons °F

Mechanical Analysis



Chiller Selection

4 Arrangements Heat Exchanger Enabled

▫ 2 – 250 ton Centrifugal Chillers

▫ Constant and Variable Speed

No Heat Exchanger▫ 1 – 150 ton Centrifugal Speed

▫ 1 – 350 ton Centrifugal Speed

▫ Variable & Constant arrangements


Mechanical Analysis



Chiller Selection

Detailed Life-Cycle Cost (LCC) Analysis▫ 8 scenarios

WSFC - Heat Exchanger On/Off 4 Chiller Combinations 2 Cooling Tower Arrangements Pumping based on 14 ºF ΔT

▫ Energy Consumption Modeled in Engineering Equation Solver (EES)

▫ Annual Utility & LCC calculated in Microsoft Excel


Mechanical Analysis



Chiller Selection LCC Analysis

▫ 8% discount rate over 15 years


E 234,987$ -- 38,202$ -- 401,265 -- 234,987$ --S - 1 223,679$ 1 34,074$ 8 342,702 6 223,679$ 2S - 2 225,393$ 2 33,164$ 6 331,866 5 225,393$ 1S - 3 254,263$ 5 32,884$ 3 328,424 4 254,263$ 6S - 4 255,977$ 6 31,771$ 1 316,361 1 255,977$ 3S - 5 308,644$ 7 33,077$ 4 330,994 3 308,644$ 8S - 6 310,358$ 8 32,011$ 2 320,504 2 310,358$ 7S - 7 245,321$ 3 33,896$ 7 359,249 8 245,321$ 5S - 8 247,035$ 4 33,082$ 5 351,176 7 247,035$ 4

N = years of analysis

LCC Rank

8.00 15

Life-Cycle Cost (LCC) Analysis

Scenario Number

First Cost Rank Utility Cost RankAnnual

Energy Use (kWh)

RankDiscount Rate (%)

Chiller Selection Scenario 2

▫ HX Enabled; 2 – 250 ton Constant Speed Chillers; NC8303DL2

Mechanical Analysis

Cost Savings

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

First Cost ($) Annual Utility Cost($)

LCC ($) Annual Energy Use(kWh)



Chiller Selection


Costs and Energy Savings

0

100000

200000

300000

400000

500000

600000

First Cost ($) Utility Cost ($) LCC ($) Annual Energy(kWh)

Existing

Scenario 2

9,594$ 4.0%

69,399 17.3%

5,038$ 13.0%

52,720$ 9.4%Total LCC Savings

Cost Savings of Scenario 2

First Cost Savings

Annual Energy Savings (kWh)

Annual Utility Costs Savings

Mechanical Analysis


Step - 5 – Adjust tower sizing and number of cells if necessary.

Step - 6 – Finalize piping system design and select pumps.

Step - 7 – Develop and optimize control sequence.


Mechanical Analysis


Comparison of two procedures

Typical Procedure

□Advantages Common in Industry Less time consuming Results in working system

□Disadvantages Not optimum design Higher initial cost Higher operational cost

Optimization Procedure

□Advantages Results in OPTIMUM system Lower initial costs Lower operational costs

□Disadvantages Time consuming

▫ Engineer▫ Equipment vendors

Not common in Industry

Mechanical Analysis


Conclusions

Is the Optimization Procedure Applicable to typical chilled water plant designs?

No

Survey Says:

Too time consuming Cost Prohibitive Extra Fee for Client

Mechanical Analysis


Conclusions

□Use 3-step procedure to determine flow rates & ΔTs

Advantages▫ Reduces First Cost

Pumps Cooling Tower Pipes, Valves, Insulation, etc.

▫ Reduces Operating Costs

Disadvantages▫ Increased Coil Sizes Offset by savings

Lighting Analysis

Intent of Analysis

□ Decrease Power Density of Lighting□ Provide adequate illumination levels

Space DescriptionRoom 133 & 212

2-story Art Gallery

874 square feet

2nd Floor Balcony

Showcase for Student Artwork


Lighting

Analysis

Lighting Analysis

Existing Design

□ 31 - Track Mounted Fixtures 75 W Parabolic Incandescent Lamps

□ 12 - Recessed Downlight Fixtures 2 - 26 W Quad Compact Fluorescent Lamps


Lighting Analysis

■ ASHRAE Standard 90.1-1999 – Energy Standard for Buildings

□ General Exhibition within a Museum□ 1.6 W/ft2


Number of Fixtures

Fixture # of Lamps -

WattageBallast Factor

Input W (w/ ballast)

Total Wattage

31 Track 1 - 75W -- 75 2325

12 Downlight 2 - 26W 1.1 57.2 686

Power Density - Existing Design

3011

874

3.45

Total Wattage (W) :

Area (ft2) :

Power Density (W/ft2) :

Lighting Analysis

New Design

□ 13 - Wallwash Fixtures 1 - 55 W Long Tube Compact Fluorescent Lamp

□ 12 - Recessed Downlight Fixtures 2 - 26 W Quad Compact Fluorescent Lamps


Lighting Analysis

■ Compliant with ASHRAE Standard 90.1-1999


Number of Fixtures

Fixture # of Lamps -

WattageBallast Factor

Input W (w/ ballast)

Total Wattage

13 Wallwash 1 - 55 W 0.98 53.9 701

12 Downlight 2 - 26W 1.1 57.2 686

Power Density - New Design

1323

874

1.51

Total Wattage (W) :

Area (ft2) :

Power Density (W/ft2) :

< 1.6 W/ft2

Lighting Analysis

■Illuminance Levels

□ IESNA Handbook Museum - flat display on a vertical surface Category D

▫ Visual tasks of high contrast and large size▫ 30 fc (300 lux)


Lighting Analysis


■ Lightscape Images

Lighting Analysis

■Advantages

□ Compliance with ASHRAE Std. 90.1-1999

□ Elimination of “hot spots”

□ Even distribution of illuminance

□ Lower maintenance costs

□ Color Temperature matches downlights

□ Longer Life

■Disadvantages

□ Reduction in Color Rendering capabilities

□ No directivity


Summary

Conclusions / Recommendations

■Mechanical Analysis

□ Optimization Procedure Not Feasible for all plant designs

▫ Cost Prohibitive▫ Time constraints

□ Selection of flow rates & ΔT 3-step procedure

▫ First Cost Savings (CAPA – 4%)▫ Operational Cost Savings (CAPA – 13%)▫ Takes only minutes to perform


Conclusions &

Recommendations

Conclusions / Recommendations

■Lighting Analysis

□ Use wallwash fixtures Reduces power density

▫ Compliance with ASHRAE Std. 90.1-1999

Even distribution of illuminance levels Adequate illuminance on display surfaces


AcknowledgementsJim Kemper - Firsching, Marstiller, Rusbarsky & Wolf Engineering, Inc.

Ken Lee - MacLachlan, Cornelius & Filoni Architects

Jamie White & Chuck Urso - LLI Technologies, Inc.

Kent Lewis - Carl J. Long & Associates

Dr. William P. Bahnfleth Prof. Moses Ling Jonathan Dougherty

Other members of the AE Faculty

Family & Friends

Questions?

Mechanical Analysis

Step 1- Determine flow rate using 12 ºF ΔT & 18 ºF ΔT




Section Load (tons) Application GPMPipe Size

(in)GPM

Pipe Size (in)

Primary Piping 500 Non-Noise Sensitive, constant speed 1000 8 667 8Main Riser 380 Noise Sensitive, variable speed 760 6 507 6AHU-4 70 Non-Noise Sensitive, variable speed 140 3 93 2-1/2AHU-5 60 Non-Noise Sensitive, variable speed 120 3 80 2-1/2

Chilled Water Flow Rate Requirements using ∆T = 12 °F and ∆T = 18 °F

∆T = 12 °F ∆T = 18 °F

Mechanical Analysis

Step 2 – Pick smallest pipe from Table 6-8 & adjust ΔT to max-out pipe size




Section Load (tons) ApplicationPipe Size

(in)Max GPM

Resulting ∆T

Primary Piping 500 Non-Noise Sensitive, constant speed 8 1115 10.8Main Riser 380 Noise Sensitive, variable speed 6 765 11.9AHU-4 70 Non-Noise Sensitive, variable speed 2-1/2 107 15.7AHU-5 60 Non-Noise Sensitive, variable speed 2-1/2 107 13.5

Chilled Water Flow Rates for Main Distribution Pipes

Section Load (tons) ApplicationPipe Size

(in)GPM ∆T

Primary Piping 500 Non-Noise Sensitive, constant speed 8 857 14.0Main Riser 380 Noise Sensitive, variable speed 6 670 13.6AHU-4 70 Non-Noise Sensitive, variable speed 2-1/2 105 16.0AHU-5 60 Non-Noise Sensitive, variable speed 2-1/2 107 13.5

Chilled Water Design flows and ∆Ts

Mechanical Analysis

Step 3 – Choose ΔT based on results



Chilled Water ΔT = 14 ºF


Mechanical Analysis


■Energy Model

□ Components modeled in EES

Chillers▫ DOE2 & Modified DOE2 model

Coupled polynomials Coefficients from California Energy Commission

Cooling Towers▫ Curve-fit polynomial regressions of performance curves

Marley Update Selection Software

Pumps▫ Polynomial equations using pump characteristics

Heat Exchanger▫ Heat transfer equations

Mechanical Analysis


■Criteria for pipe-sizing of Table 6-8

□ Velocity is limited to minimize erosion Based on common rules-of thumb

□ Velocity limited by noise Based on general rules-of-thumb

□ Life-cycle cost of piping and associated pumping system

Analysis performed in San Francisco Bay Area (1992)

Existing Conditions

Mechanical□ 2 – 260 ton Water-cooled Centrifugal Chillers□ 1 – 2 cell cooling tower - 1560 gpm□ 2 – 3,853 MBtu Natural Gas Boilers□ Plate & Frame Heat Exchanger for Water-Side Free

Cooling (WSFC)□ Heat Recovery Unit□ 10 Air Handling Units□ VAV, CAV, & Direct Ventilation□ Carbon Dioxide Monitors□ 40+ Sound Attenuators□ Integrated DDC & Pneumatic Control System


the center for the creative and performing arts high school

Documents

pa slide

arts high school slide

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