The University of Texas at Austin Fall 2014CAEE Department, Architectural Engineering Program

Course: HVAC Design ARE 346P/CE 389H

Instructor: Dr. Novoselac, AtilaECJ, 5.422Office (512) 475-8175 e-mail: atila@mail.utexas.eduhttp://www.ce.utexas.edu/prof/Novoselac

Office Hours: Tuesday and Thursday 11:00 – 12:00 p.m.

Objectives

• Introduce course syllabus and establish

ground rules

• Describe class content

• Address any of your concerns

Introduce yourself

• Name?

• Department?

• Your professional interest?

HVAC systems

• Systems that: • Cost very much (residential 10-20% , commercial 20-50% of total cost)

• Uses the most energy• Most strongly influences our comfort• Has great potential to improve/degrade our health

• No longer taught in ME (at UT)

• Very high demand for graduates

Motivation for studying HVAC systems

• Responsible for ~40% of energy consumption

• ~90% of our time is spent indoors

• HVAC systems are a central part of every building

Prerequisites

• Building Environmental SystemsFamiliarity with HVAC

• ThermodynamicsPsychrometrics, phase change, properties

• Fluid MechanicsFlow in pipes and ducts, non-dimensional numbers

Useful but not necessary• Heat Transfer

Conduction, convection, radiation

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 Objectives

Course Topics

• Background, Introduction and Review 2 wks• Heating and Cooling Loads 1 wk• Psychrometrics and mass transfer 1 wk• Air conditioning and refrigerant cycles 2 wks• Chillers and Boilers 1 wk • Coils and heat exchangers 2 wks• Ducts, air, and water systems 2 wks• Large HVAC Systems 2 wk• HVAC Control 2 wk• Final Project, field trip 1 wk• 15 wks

What am I NOT covering?

• Detail calculation of Cooling/Heating loads• Human comfort/Indoor air quality• Furnaces and boilers• Absorption cycle refrigeration• Energy generation (heat and power, cogeneration)• District heating and cooling (campus or city scale)

This is a skills class

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

• You will be able to size most HVAC components, design smaller and medium size systems and understand larger systems

• Kuehn, T.H.; Ramsey, J.W.; Threlkeld, J.L. 1998. Thermal Environmental Engineering (3rd Edition) Prentice Hall ISBN: 0139172203

• First edition was 1962

• Excellent graduate/undergraduate textbook

• Thorough, fundamental, many examples

• Look forward to your opinion

• Other books are optional

Textbook

• Mid-Term Exam 30%• Project 35%• Homework Assignments 30%• Participation 5%

100%

• Homework is a large part of your grade• ~ Weekly assignments, reducing in intensity by the end of semester• 10% penalty per day for late assignments

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

Grading

HWs (30%)

• Four homeworks- Combination of

- book problems- design problems I made

• You can work to together but each student should submit individual assignment • NOT a copy of summons work

• HW deadline is at the end of the day

Project (35%)

• Final Project- Undergraduates - group assignment

- Graduates – individual assignment

• Design HVAC component and systems • Assigned in late October

• Final project will have written (report) and oral (presentation) components

Exam (30%)

• One open-book midterm exam: • November 13 tentative

• 1 or 2 longer problem(s)• Few short answer questions

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

My Issues

• Please don’t come to my office between 8:30 and 9:30 am on Tuesday and Thursday• Class preparation

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

• Suggestion are welcome

Course Website

• All class information online

• http://www.ce.utexas.edu/prof/Novoselac/classes/ARE389H/

• PLEASE LET ME KNOW ABOUT ERRORS

TENTATIVE COURSE SCHEDULE

Your questions ?

The Big Picture

• HVAC systems need to provide conditioned and acceptable air quality in buildings• Heating, Cooling, Ventilation

• Heating, cooling, ventilation loads

Systems: Heating

• Make heat (furnace, boiler, solar, etc.)

• Distribute heat within building (pipes, ducts, fans, pumps)

• Exchange heat with air (coils, strip heat, radiators, convectors, diffusers)

• Controls (thermostat, valves, dampers)

Systems: Cooling

• Absorb heat from building (evaporator or chilled water coil)

• Reject heat to outside (condenser)• Refrigeration cycle components (expansion valve,

compressor, concentrator, absorber, refrigerant)• Distribute cooling within building (pipes, ducts, fans,

pumps)• Exchange cooling with air (coils, radiant panels,

convectors, diffusers)• Controls (thermostat, valves, dampers, reheat)

Systems: Ventilation

• Fresh air intake (dampers, economizer, heat exchangers, primary treatment)

• Air exhaust (dampers, heat exchangers)• Distribute fresh air within building (ducts,

fans)• Air treatment (filters, etc.)• Controls (thermostat, CO2 and other

occupancy sensors, humidistats, valves, dampers)

Systems: Other

• Auxiliary systems (i.e. venting of combustion gasses)

• Condensate drainage/return

• Dehumidification (desiccant, cooling coil)

• Humidification (steam, ultrasonic humidifier)

• Energy management systems

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 fluid 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