Next Class: Text 1.5 hour long Open book, open notes - Comprehensive 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 Review for the Exam Example Answer your

Frictional Losses

Non-circular Ducts Parallel concept to wetted perimeter

Dynamic losses Losses associated with Two methods Changes in velocity Obstructions Bends Fittings and transitions Two methods Equivalent length and loss coefficients

Loss Coefficients ΔPt = CoPv,0

Electrical Resistance Analogy

Example 18.7 Determine total pressure drop from 0 to 4

Fan selection Calculated DP and V

Fan Performance

Conversion Between Methods Se Example 18.8 and compare with 18.7

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

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

Direct Contact (10) Purpose of cooling towers Psychrometrics Describe how a cooling tower works

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

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

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

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

Duct layout/design (18) Equal friction method Supply or return systems Balance the system