ARE377K/ARE389H/CE389HHVAC Design

Dr. Siegel

• Objectives• Demonstrate knowledge of syllabus and ground

rules• Describe class content

• Address any of your concerns

Motivation

• Who are you?

• Grad/undergrad?

• Department?

• Why are you here?

HVAC systems

• The part of our buildings that• Costs the most money• Uses the most energy• Most strongly influences our comfort• Has great potential to improve/degrade our health

• No longer taught in ME

• Very high demand for graduates

• Amazing microenvironment

Buildings

• Responsible for ~35% of energy consumption

• ~90% of our time is spent indoors

• Construction is one of the largest industries in the world

• HVAC systems are a central part of every building

The University of Texas at Austin Fall 2005Dept. of Civil Engineering Architectural Engineering Program

Course: HVAC Design (ARE 377K/CE 389H/ARE 389H)

Prerequisites: Any three of ARE 346N, CE 319F, ME 320/326, ME 339 or consent of instructor

Professor: Dr. Jeffrey SiegelECJ, Rm. 5.302 , PRC-CEER 1.304512-471-2410; LAB 512-471-9688; FAX 512-471-3191e-mail: jasiegel@mail.utexas.eduhttp://www.ce.utexas.edu/prof/siegel/home.html

Office Hours: Tuesday 3:30 -5:00 p.m., Thursday 12 – 1:00 p.m.

Website: http://www.ce.utexas.edu/prof/siegel/classes/ARE389H_F05/

Prerequisites (any 3)

• Building Environmental Systems• Familiarity with HVAC

• Thermodynamics• Psychrometrics, phase change, properties

• Heat Transfer• Conduction, convection, radiation

• Fluid Mechanics• Flow in pipes and ducts, non-dimensional

numbers

My Quirks

• Please don’t come to my office between 1 and 2 pm on Tuesday and Thursday• Class preparation and teaching time

• Please don’t use e-mail to ask me “content” questions• Call me or come see me

• I care about your learning• I listen to your comments

• The more specific the better

What have you heard about this class?

• Too hard (18 of 23 students)• Covering less material in more depth

• Want more applied material (10 of 23 students)• Applied problem solving classes• Take home exams (3 over course of semester)• Final project configured to be easier

• Take home exam was too hard (22 of 23 students)• Will make them easier

1. Apply fundamental physical principles to HVAC design

2. Describe and size each component in an HVAC system

3. Design HVAC systems based on manufacturer’s datasheets

4. Contrast residential systems with commercial systems and use appropriate design techniques for each type of system

5. Solve HVAC design problems with high-quality references

Course ObjectivesBy taking this class you will be able to..

This is a skills class

• I expect you to come away from this class and be able to understand everything that you see in HVAC system or know where to go to learn about it.

• You will be able to size most HVAC components and design smaller systems

• Kuehn, T.H.; Ramsey, J.W.; Threlkeld, J.L. 1998. Thermal Environmental Engineering (3rd Edition) Prentice Hall ISBN: 0139172203• NOTE VERSION ISSUE: Reprinted with corrections, 2001

• First edition was 1962

• Excellent graduate textbook

• Thorough, fundamental, many examples

• Look forward to your opinion (16 of 23 liked it in 2004)

• Other books are optional

Textbook

Midterm (take home) 25%Projects 25%Homework Assignments 45%Participation 5%

100%

• Homework is a large part of your grade• ~ Weekly assignments, tapering off by end of semester• 10% penalty per day for late assignments

• You are allowed to work together, but each student must prepare their own solution

• Copying is expressly forbidden by UT policy

Grading

Other Notes About Grading

• Last year 19 A, 3 B, 1 C

• Class is hard, but I reward effort

• If you do a good job on all assignments, exams, and projects, you will get an A• I have no problem giving As to everyone in the

class.• (I also have no problem giving Cs to everyone in

the class)

Take Home Exams

• You will have a weekend to do each exam (except for last one• You must work alone• Open book/open notes• Expect them to be challenging

• 25% of final grade

Participation

• My assessment of your participation in the class• 5% of total grade

• How to get participation points• Come to class and be on time• Submit all assignments/project on time• Participate in class

Project- Component Based Learning

• You will have some choice in topic area

• Project assigned 9/20• Write-up due 12/8• Presentation 12/6

• 25% of final grade

Date Topic Assigned Reading

9/1- 9/13 Course introduction and review Chapters 2, 7

9/15- 9/20 Psychrometrics (Project assigned 9/20) 8

9/22Moist air / water mass transferCooling towers and evaporative coolers

10

9/27-9/29Thermodynamic cyclesAir conditioners and heat pumps

3

10/4Refrigerants, compressors, and expansion valves

4

10/6 Problem Solving Session 1 (Take Home Test 1)

10/11-10/20 Heat Exchangers and Coils 11

10/25-11/3Air systemsDucts and duct design, fans

18

11/8 Hydronic (water) systems and pumps 19

11/10 Problem Solving Session 2 (Take Home Test 2)

11/15,11/17 HVAC controls handout

11/22 Residential HVAC systems

11/29 Problem Solving Session 3 (Take Home Test 3)

12/1-12/8 Overflow, Field Trips, Project presentations

What am I not covering?

• Furnaces/boilers

• Human comfort/ indoor air quality

• Absorption cycle refrigeration

• Cryogenics

• Energy generation

• Heating and cooling loads

Class Website

• http://www.ce.utexas.edu/prof/siegel/classes/ARE389H_F05/

• Date is in filename (i.e. 389H_090105)

• Use PDFs and PPTs – can cut and paste text, follow links

• PLEASE LET ME KNOW ABOUT ERRORS

Missed Classes

• Very unfortunate, but I need to miss next two classes (9/6 and 9/8)• Indoor Air 2005 in Beijing (Every three years,

most important conference in my field)• Authored 4 papers, 2 Forums, Chairing 1 session

• Numerous meetings

• Video-recorded 2 lectures• On class website• Dr. Novoselac has agreed to answer any questions

Any Questions ?

Why HVAC?

• Heating, cooling, ventilation (of buildings)• Energy and mass transfer between inside and

outside• Energy and mass transfer within buildings

Cooling coil•Heat transfer from air to refrigerant•Extended surface coil

Drain Pain•Removes moisture condensed from air stream

Condenser

Expansion valve

Controls

Compressor

Heating coil•Heat transfer from refrigerant to air

Heat pump

Furnace

Boiler

Electric resistance

Controls

Blower•Overcome pressure drop of system

Adds heat to air stream

Makes noise

Potential hazard

Performs differently at different conditions (air flow and pressure drop)

Duct system (piping for hydronic systems)•Distribute conditioned air•Remove air from space

Provides ventilation

Makes noise

Affects comfort

Affects indoor air quality

Diffusers•Distribute conditioned air within room

Provides ventilation

Makes noise

Affects comfort

Affects indoor air quality

Dampers•Change airflow amounts

Controls outside air fraction

Affects building security

Filter•Removes pollutants•Protects equipment

Imposes substantial pressure drop

Requires Maintenance

Controls•Makes everything work

Temperature

Pressure (drop)

Air velocity

Volumetric flow

Relative humidity

Enthalpy

Electrical Current

Electrical cost

Fault detection

Goals of this class

• Use thermodynamics, fluid mechanics, heat transfer, control theory, physics, critical analysis to design HVAC systems that work

Date Topic Assigned Reading

9/1- 9/13 Course introduction and review Chapters 2, 7

9/15- 9/20 Psychrometrics (Project assigned 9/20) 8

9/22Moist air / water mass transferCooling towers and evaporative coolers

10

9/27-9/29Thermodynamic cyclesAir conditioners and heat pumps

3

10/4Refrigerants, compressors, and expansion valves

4

10/6 Problem Solving Session 1 (Take Home Test 1)

10/11-10/20 Heat Exchangers and Coils 11

10/25-11/3Air systemsDucts and duct design, fans

18

11/8 Hydronic (water) systems and pumps 19

11/10 Problem Solving Session 2 (Take Home Test 2)

11/15,11/17 HVAC controls handout

11/22 Residential HVAC systems

11/29 Problem Solving Session 3 (Take Home Test 3)

12/1-12/8 Overflow, Field Trips, Project presentations

Important Dates

• No classes on Thursday 24 November due to Thanksgiving holiday.

• Take Home Tests• Assigned 10/6 due 10/11• Assigned 11/10 due 11/15• Assigned 11/29 due 12/1

• Project assigned Tuesday 20 September• Oral Presentations 12/6, Written Report due 12/8

• No final exam, no oral exam