next class: text
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Next Class: Text. 1.5 hour long Bee in class at 12:20 pm Open book, open notes - Comprehensive Next week (Monday at 10-12) extra office hours related to the Test. Objectives. Finish with Ducts design Example Review for the Exam Answer your. Frictional Losses. Non-circular Ducts. - PowerPoint PPT PresentationTRANSCRIPT
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Next Class: Text
1.5 hour long- Bee in class at 12:20 pm
Open book, open notes
- Comprehensive
Next week (Monday at 10-12) extra office hours related to the Test
![Page 2: Next Class: Text](https://reader033.vdocuments.us/reader033/viewer/2022050805/5681503b550346895dbe37bf/html5/thumbnails/2.jpg)
Objectives
• Finish with Ducts design • Example
• Review for the Exam• Answer your
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Frictional Losses
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Non-circular Ducts
• Parallel concept to wetted perimeter
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Dynamic losses
• Losses associated with• Changes in velocity• Obstructions• Bends• Fittings and transitions
• Two methods
• Equivalent length and loss coefficients
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Loss Coefficients 20
1
0
1
VV
CC
»ΔPt = CoPv,0
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Electrical Resistance Analogy
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Example 18.7
• Determine total pressure drop from 0 to 4
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Fan selection
• Calculated DP and V
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Fan Performance
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Conversion Between Methods
f
DCL
g
VC
gD
VLf
eq
eq
0
2
0
2
22
Se Example 18.8 and compare with 18.7
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Review for the Exam
• Should be able to do all calculations associated with lectures as well as HWs• Problems may deal with context
• i.e. Explain how thermal conductivity influences fin efficiency? Holding all other parameters equal, how important is increasing the thermal conductivity
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Psychrometrics and Processes (7 & 8)
• Know all parameters and their location/orientation on a psychrometric chart
• Be able to look up conversions of parameters on a psychrometric chart and with calculations
• Use protractor to calculate SHR and ΔW/Δh
• Plot processes on a chart for real buildings• List what is held constant for different processes
• Describe processes in AHUs in psychrometric chat
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Direct Contact (10)
• Purpose of cooling towers
• Psychrometrics
• Describe how a cooling tower works
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Cycles (3), Refrigerants (4)
• Describe Carnot cycle and components• Understand constant variables for each component
• List, describe, and calculate inefficiencies
• Use figures, refrigerant tables and equations for different substances
• List important parameters for refrigerant selection/differentiation
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Heat Exchangers (11)
• Differentiate types
• Calculate ε, and UA, etc.
• Complete broad analysis• Which m is larger, which Δt is larger?
• Within and between heat exchangers
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Heat Exchangers (11)
• Calculate and compare different thermal resistances
• Describe influence of key factors
• Integrate different parameters/resistances
• Manipulate UA equation
• Describe differences for wet and dry heat exchangers
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Diffusers, Duct Components (18)
• Select diffusers• Define all terms on manufacturer data sheets
• Calculate pressure drop of:• Straight duct• Duct fittings
• Differentiate fans and describe fan curves
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Duct layout/design (18)
• Equal friction method• Supply or return systems• Balance the system