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Course Exam

Next Thursday (April 15) 7 pm

Same classroom (ECJ 7.208) 2.5-hour exam

Open book open notes

All problem types of questions (short but comprehensive)

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Objectives

Finish the pumps and plumbing systems

Discuss the final project

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Pumps and Plumbing

Very similar to fans and ducts

Same principles based on fluid dynamics

With some specifics

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Hydronic Terms

Head loss

Open-loop vs. closed loop

2-pipe vs. 4-pipe

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Head Loss

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Table 19.1

Pipe dimensions for standard pipe

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Fittings

g

Vkh

2

2

!(

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Pumps

Driving force to move air water in buildings

Raise pressure and produce flow

One main type Centrifugal

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Pump curves

NPSHR = Net Positive Suction Head Required

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Finding Volumetric Flow

Same procedure as for air

Intersection of pump curve and system curve

How can you control flow?

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Changing Pump Speed

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Use Multiple Pumps

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Plumbing Arrangements

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Example 19.7

Similar to equal friction method

Calculate head loss for common pieces of

system Size pipes to have equal head loss between

points 2 and 3

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Review for the Exam

Should be able to do all calculations associated

with lectures as well as HW1

Questions/problems may deal with context i.e. Explain how thermal conductivity influences finefficiency? 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 parameterson a psychrometric chart and with calculations

Use protractor to calculate SHR and W/h

P

lot processes on a chart for real buildings List what is held constant for different processes

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Direct Contact (10)

Describe how a cooling tower works

Describe analysis procedure for direct contact

devices

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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

Contrast different refrigerants List important parameters for refrigerant

selection/differentiation

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Heat Exchangers (11)

Differentiate types

Calculate NTU, , cr, R, P, F, m, UA, etc.

Complete broad analysis Which m is larger, which t 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/parameters of relevancefor wet 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

Components (coils, VAV boxes, dampers, etc.)

Differentiate fans and describe fan curves

Use fan laws

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Duct layout/design (18)

Describe static regain method

Compare to equal friction method

Supply or return systems Balance the system

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Project

Design problem For example: Given cooling and heating load designHVAC for the building

Research problem Analysis based problem. For example:

Find the optimum solution for.

Developed control strategy for

Life cycle cost analysis for

.