Benjamin Banneker Elementary Milford, DE Michelle M. Baldwin - PowerPoint PPT Presentation

Benjamin Banneker Elementary Milford, DE Michelle M. Baldwin Mechanical Option

Presentation Outline � Existing Conditions � Existing Mechanical System � Analysis of Mechanical Redesign � Dedicated Outdoor Air System � Radiant Panels � Fire Protection � Economic Analysis � Lighting � Conclusions Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Existing Conditions � Project Team � Owner: Milford School District � Mechanical: Furlow Associates � Electrical: Carew Associates � Structural: Baker Ingram Associates � General Contractor: Conventional Builders � Building Cost: $8,195,200 � Building Size: 64,600 ft 2 � Dates of Construction � Start: January 2002 � Finish: October 2003 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

� Architecture � Building Exterior � Decorative concrete block with a stacked bond � Prefinished metal panels � Metal awnings Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

� First Floor Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

� Second Floor Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

� Electrical � 750 KVA transformer � 208/120 V, 3 phase, 4 wire � 70 A emergency generator � Classroom Lighting � Direct/indirect fluorescent suspended fixtures Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

� Structural � Structural steel joists and girders � Non-composite floor system � 14’ floor to floor height � 10’ ceiling height � Construction Management � New school built on the same site as existing school Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Existing Mechanical System � Dedicated Outdoor Air System � Two Energy Recovery Units (ERU) � Six Roof-top units � Air-cooled chiller � Fire-Tube Boilers � Two-Pipe System � Unit Ventilators � Fan Coil Units � Fin-Tube Radiation Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Mechanical System Flow Diagram Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Existing Mechanical System � Supply Air Temp: 75 ˚ F � Terminal unit supply air temp: � Cooling – 55 ˚ F � Heating – 150 ˚ F � Space dew point temp: 57 ˚ F � Space relative humidity: 53% � Latent and Sensible load on the terminal units Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Mechanical Redesign Goals � Remove the existing terminal units � Add radiant panels � Decouple the Sensible and Latent Loads � Decrease the supply air temperature � Resize the cooling coil � Reduce the dew point temperature � Determine radiant panel supply water temperature Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Mechanical Redesign � Noise in Classrooms � Decrease in ability to learn as background noise increases � HVAC systems are the major source of background noise � Classroom rating – NC 30dB � Unit Ventilators – NC 45dB � Typical classroom with unit ventilators – NC 50 - 55dB Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Dedicated Outdoor Air System 1. Outdoor air inlet 2. Enthalpy Wheel 3. Cooling and Heating Coils � 100% Outdoor Air � 15 cfm/person � Energy Recovered from the return air stream without mixing Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Dedicated Outdoor Air System Cooling � Outdoor air inlet: � 93 ˚ F Enthalpy Wheel � outlet: 81 ˚ F Heating � Outdoor air inlet: � 14 ˚ F Enthalpy Wheel � outlet: 54 ˚ F Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

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 ˚ F � Reheat Coils Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Radiant Panels � Invensys RCU-166 panels � Piping Connection � Panel Shape Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Radiant Panels Room Air Temperature ° F 75 Temperature Water Inlet ° F 56 Temperature Water Outlet ° F 59 Total Ceiling Area in ft 2 800 Total RCU Area in ft 2 per Module 10.40 Room Ceiling Height ft 8.50 Total Cooling Capacity BTUH/ft 2 Active Area 53.41 Water Flow RCU per Module in gal/min 0.37 Total Number of Panels 844 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Controls � Thermostat control � Heating Coils � Radiant Panels � Condensation Risk � Operable windows � Outdoor humidity Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Fire Protection � Integration of sprinkler piping and radiant panel piping � Normal Flow control � Chilled water supplied to radiant panels � Fire Flow control � Water supplied directly to sprinkler heads Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Flow Diagram Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Economic Analysis � First Cost Analysis Equipment Removed Unit Fin-Tube Fan-Coil Condensate Ventilators Radiators Units Piping $111,300 $2,760 $39,000 $6,634 Total Equipment Added Radiant Piping Reheat Coils Valves Pumps Panels Total $114,109 $11,210 $21,000 $26,498 $900 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Energy Analysis � Initial System Total Cost: $ 69,414 Cooling Cooling 22.6% 22.6% 22.9% Air System Fans 22.9% Air System Fans Heating Heating 2.2% 2.2% Pumps Pumps 1.9% 1.9% 21.0% Electric Equipment 21.0% Electric Equipment Lights Lights 29.5% 29.5% Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Energy Analysis � Redesigned System Total Cost: $ 65,292 Cooling Cooling 23.2% 23.2% Heating Heating 4.0% 4.0% 15.6% Air System Fans 15.6% Air System Fans Pumps Pumps 3.6% 3.6% 22.3% Electric Equipment 22.3% Electric Equipment Lights Lights 31.4% 31.4% Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Economic Analysis Summary � First Cost Analysis Summary Mechanical Cost $1,182,675 Minus $159,693 $173,717 Plus Total $1,196,699 Additional Cost $14,024 � Energy Analysis Summary � The redesigned system is $4,122 less expensive annually � Payback period is 3.4 years Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Lighting � 30 fc on task surface � 1.5 W/ft 2 � 3 types of light fixtures considered � Direct/Indirect fluorescent suspended fixture � Direct recessed fluorescent fixture � Direct fluorescent suspended fixture Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Indirect/Direct Suspended Fluorescent Fixtures � 48.6 fc � 1.07 W/ft 2 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Direct Recessed Fluorescent Fixture � 45.6 fc � 0.89 W/ft 2 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Direct Suspended Fluorescent Fixture � 40.1 fc � 1.31 W/ft 2 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Lighting Recommendation � Direct fluorescent suspended fixtures � 40.1 fc > 30 fc � No shadows � 1.31 W/ft 2 < 1.5 W/ft 2 Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Conclusions � Advantages � Lower Annual Energy Cost � Short Payback Period � Increased System Control Flexibility � Increased Floor Area � Decreased Background Noise � Increased Comfort � Increased Learning Ability � Disadvantages � More Complicated Controls � Higher First Cost Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

Thanks � Furlow Associates � Dr. Mumma � AE Department � Friends & Family Michelle Baldwin Benjamin Banneker Elementary Mechanical Option AE Senior Thesis Spring 2003

?? Questions ?? AE Senior Thesis Spring 2003