Benjamin Banneker ElementaryMilford, DE
Michelle M. BaldwinMechanical Option
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Presentation OutlineExisting ConditionsExisting Mechanical SystemAnalysis of Mechanical Redesign
Dedicated Outdoor Air SystemRadiant Panels
Fire ProtectionEconomic AnalysisLightingConclusions
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Project TeamOwner: Milford School DistrictMechanical: Furlow AssociatesElectrical: Carew AssociatesStructural: Baker Ingram AssociatesGeneral Contractor: Conventional Builders
Building Cost: $8,195,200Building Size: 64,600 ft2Dates of Construction
Start: January 2002Finish: October 2003
Existing Conditions
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
ArchitectureBuilding Exterior
Decorative concrete block with a stacked bondPrefinished metal panels Metal awnings
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
First Floor
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Second Floor
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Electrical750 KVA transformer208/120 V, 3 phase, 4 wire70 A emergency generator
Classroom LightingDirect/indirect fluorescent suspended fixtures
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
StructuralStructural steel joists and girdersNon-composite floor system14’ floor to floor height10’ ceiling height
Construction ManagementNew school built on the same site as existing school
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Existing Mechanical SystemDedicated Outdoor Air System
Two Energy Recovery Units (ERU)Six Roof-top unitsAir-cooled chillerFire-Tube BoilersTwo-Pipe System
Unit VentilatorsFan Coil UnitsFin-Tube Radiation
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Mechanical System Flow Diagram
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Existing Mechanical SystemSupply Air Temp: 75˚FTerminal unit supply air temp:
Cooling – 55˚FHeating – 150˚F
Space dew point temp: 57˚FSpace relative humidity: 53%Latent and Sensible load on the terminal units
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Mechanical Redesign GoalsRemove the existing terminal units
Add radiant panels
Decouple the Sensible and Latent LoadsDecrease the supply air temperature
Resize the cooling coil
Reduce the dew point temperatureDetermine radiant panel supply water temperature
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Mechanical RedesignNoise in Classrooms
Decrease in ability to learn as background noise increasesHVAC systems are the major source of background noise Classroom rating – NC 30dBUnit Ventilators – NC 45dBTypical classroom with unit ventilators –NC 50 - 55dB
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Dedicated Outdoor Air System
1. Outdoor air inlet2. Enthalpy Wheel 3. Cooling and
Heating Coils
100% Outdoor Air15 cfm/personEnergy Recovered from the return air stream without mixing
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Dedicated Outdoor Air SystemCooling
Outdoor air inlet: 93˚FEnthalpy Wheel outlet: 81˚F
HeatingOutdoor air inlet: 14˚FEnthalpy Wheel outlet: 54˚F
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Mechanical Redesign
ERU supply temperature reduced from 75˚F to 50˚F
Resized Cooling Coil
Relative humidity reduced from 53% to 49%Dew point temperature reduced from 57˚F to 54˚FReheat Coils
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Radiant Panels
Invensys RCU-166 panelsPiping ConnectionPanel Shape
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Radiant PanelsRoom Air Temperature °F 75
Temperature Water Inlet °F 56
Temperature Water Outlet °F 59
Total Ceiling Area in ft2 800
Total RCU Area in ft2 per Module 10.40
Room Ceiling Height ft 8.50
Total Cooling Capacity BTUH/ft2 Active Area 53.41
Water Flow RCU per Module in gal/min 0.37
Total Number of Panels 844
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Controls
Thermostat controlHeating CoilsRadiant Panels
Condensation RiskOperable windowsOutdoor humidity
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Fire ProtectionIntegration of sprinkler piping and radiant panel piping
Normal Flow controlChilled water supplied to radiant panels
Fire Flow controlWater supplied directly to sprinkler heads
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Flow Diagram
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Economic AnalysisFirst Cost Analysis
$6,634$39,000$2,760$111,300Total
Condensate Piping
Fan-Coil Units
Fin-Tube Radiators
Unit Ventilators
Equipment Removed
$900$26,498$21,000$11,210$114,109Total
PumpsValvesReheat CoilsPipingRadiant Panels
Equipment Added
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Energy AnalysisInitial System Total Cost: $69,414
22.9% Air System Fans
22.6%Cooling
2.2%Heating 1.9%Pumps
29.5%Lights
21.0% Electric Equipment
22.9% Air System Fans
22.6%Cooling
2.2%Heating 1.9%Pumps
29.5%Lights
21.0% Electric Equipment
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Energy AnalysisRedesigned System Total Cost: $ 65,292
15.6% Air System Fans
23.2%Cooling
4.0%Heating
3.6%Pumps
31.4%Lights 22.3% Electric Equipment
15.6% Air System Fans
23.2%Cooling
4.0%Heating
3.6%Pumps
31.4%Lights 22.3% Electric Equipment
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Economic Analysis SummaryFirst Cost Analysis Summary
$14,024Additional Cost
$1,196,699Total
$173,717Plus
$159,693Minus
$1,182,675Mechanical Cost
Energy Analysis SummaryThe redesigned system is $4,122 less expensive annuallyPayback period is 3.4 years
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Lighting30 fc on task surface
1.5 W/ft2
3 types of light fixtures consideredDirect/Indirect fluorescent suspended fixtureDirect recessed fluorescent fixtureDirect fluorescent suspended fixture
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Indirect/Direct Suspended Fluorescent Fixtures
48.6 fc1.07 W/ft2
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Direct Recessed Fluorescent Fixture
45.6 fc0.89 W/ft2
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Direct SuspendedFluorescent Fixture
40.1 fc1.31 W/ft2
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
Lighting RecommendationDirect fluorescent suspended fixtures40.1 fc > 30 fcNo shadows1.31 W/ft2 < 1.5 W/ft2
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
ConclusionsAdvantages
Lower Annual Energy CostShort Payback PeriodIncreased System Control FlexibilityIncreased Floor AreaDecreased Background Noise
Increased ComfortIncreased Learning Ability
DisadvantagesMore Complicated ControlsHigher First Cost
Benjamin Banneker ElementaryAE Senior Thesis Spring 2003
Michelle BaldwinMechanical Option
ThanksFurlow AssociatesDr. MummaAE DepartmentFriends & Family
?? Questions ??
AE Senior ThesisSpring 2003