Download - TO START YOUR CAREER AS AN HVAC ENGINEER

STEP BY STEP GUIDE

TO START YOUR CAREER AS AN

HVAC ENGINEER

© 2021 AEC Learn | ALL RIGHTS RESERVED | WWW.AECLEARN.COM

Step 1 | Review thermal-fluids

Thermodynamics, Heat Transfer, and Fluid Mechanics

are the fundamental concepts that every HVAC

Engineer need to understand.

HVAC Engineers use their broad knowledge of

thermal-fluid concepts to combine variety of equipment and components to create

systems that control temperature, humidity, and air quality in enclosed spaces.

If you are currently a senior year student or a recent graduate of a Mechanical

Engineering program, you already know thermal fluids’ fundamentals and you can go

to Step 2.

If you got your engineering degree a while ago and forgot some of the concepts,

don’t worry! It only takes a few weeks for you to review thermal fluid fundamentals as

you only need to refresh your memory on concepts. See next page for a list of concepts

that you need to review.


Thermodynamics Fluid Mechanics Heat Transfer Preliminaries:

• Units and Dimensions

• State of Substance

• Temperature

• Pressure

• Energy

• Equality of Temperature

• The Zeroth Law of

Thermodynamics

• Temperature Scales

Preliminaries:

• Units and Dimensions,

• Density

• Specific Weight

• Specific Gravity

• Viscosity

• Compressibility

• Vapor Pressure

Preliminaries:

• Units and Dimensions

• Heat Transfer Modes

• Conservation of Energy

• Efficiency of Heat Engines

Properties of Substance:

• P-V-T Surfaces (diagrams)

• Tables of Thermodynamic

Properties

• Two-Phase States

• Solid and Liquid States

• Ideal Gas State

Fluid Statics:

• Pressure in Incompressible

and Compressible Fluids

• Standard Atmosphere

• Measurement of Pressure

Conduction Heat Transfer:

• Conduction Concept,

• One-Dimensional and

Steady State Conduction

• Thermal Conductivity

• Thermal Resistant

• Overall Heat Transfer

Coefficient

Energy Equation:

• The First Law of

Thermodynamics

• Work and Heat

• Energy Equation

• Enthalpy

• Specific Heat

Bernoulli Equation:

• Newton’s Second Law in

Fluids

• Bernoulli Equation

• Restrictions on Using

Bernoulli Equation

Convection Heat Transfer:

• Convection Concept

• Convection Coefficient

Energy Analysis:

• Conservation of Mass

• Conservation of Energy

• Steady State Process

• Transient Process

Differential Analysis of Fluid

Flow:

• Conservation of Mass

• Conservation of Linear

Momentum

• Inviscid Flow

• Bernoulli Equation for

Inviscid Flow

Heat Exchangers:

• Heat Exchangers Coefficient

• Log Mean Temperature

Difference

• Heat Exchanger Design and

Performance Calculation

The Second Law of

Thermodynamics:

• Heat Engines and

Refrigerators

• The Second Law of

Thermodynamics

• Carnot Cycle

Viscous Flows in Pipes:

• Laminar and Turbulent

Flow

• Fully Developed Flows

• Moody Chart

• Major and Minor Losses

• Pipe Flow Measurements

Radiation Heat Transfer:

• Radiation Concepts

• Radiation Heat Fluxes

Power and Refrigeration

Systems with Phase Change:

• Power Cycle

Turbomachines:

• Basic Concepts

• Centrifugal Pumps


• Combined Heat and Power

Generation Cycle

• Refrigeration Cycle

• Vapor Compression

Refrigeration Cycle

• Dimensionless Parameters

and Similarity Laws

• Axial Flow and Mixed Flow

Pumps

• Fans

• Turbines

• Compressors

Power and Refrigeration

Systems with Gaseous Fluids:

• Air Standard Power Cycle

• Brayton Cycle

• Diesel Cycle

• Air Standard Refrigeration

Cycle

Gas Mixtures:

• Mixture of Ideal Gases

• Model of Gas-Vapor

Mixture

• Energy Equation for Gas-

Vapor Mixtures

• Adiabatic Saturation

Process

• Wet-Bulb, Dry-Bulb, and

Psychrometric Chart

Great textbooks for your review

Thermodynamics Fluid Mechanics Heat Transfer

Thermodynamics: An

Engineering Approach

By Yunus Cengel and Michael Boles

Amazon Link Here

Fundamentals of Fluid

Mechanics

By Bruce R. Munson, Donald F.

Young, Theodore H. Okiishi

Amazon Link Here

Fundamentals of Heat and

Mass Transfer

by Frank P. Incropera, David P.

DeWitt, Theodore L. Bergman,

Adrienne S. Lavine

Amazon Link Here

https://www.amazon.com/Thermodynamics-Engineering-Approach-Yunus-%C3%87engal/dp/1259822672/ref=sr_1_6?dchild=1&keywords=Yunus+Cengel&qid=1618680476&s=books&sr=1-6

https://www.amazon.com/Fundamentals-Fluid-Mechanics-Bruce-Munson/dp/1118116135/ref=sr_1_1?dchild=1&keywords=fundamentals+of+fluid+mechanics&qid=1618680659&s=books&sr=1-1

https://www.amazon.com/Fundamentals-Heat-Transfer-Frank-Incropera/dp/0471457280/ref=sr_1_7?dchild=1&keywords=heat+transfer+incropera&qid=1618680910&s=books&sr=1-7


Step 2 | Learn about HVAC systems

and equipment

Learn about the most common types of heating,

cooling, and ventilating systems and their

components. Here is a list of the most common

systems and equipment that you need to be familiar with. Name of one or two major

manufacturers of each equipment is added in parenthesis. Make sure to google them

and check some of their equipment catalogs.

Air Systems

Air Types

• Supply Air

• Return/Circulation Air

• Exhaust Air

Air Central Systems

• Direct Expansion Split System (Daikin, Carrier)

• Direct Expansion Packaged System (Daikin,

Carrier)

• Air Handling Unit (Daikin, Trane)

• Fan (Greenheck, Twin City)

• Dedicated Outside Air System (Daikin, Trane)

Exhaust Systems

• General Building Exhaust System

• Laboratory Exhaust

• Process Exhaust

• Ventilation for Cooling

Air Terminal Equipment • Registers, Grilles, and Diffusers (Titus)

• VAV Box (Daikin, Carrier)


Hydronic Systems

Hydronic System Types

• Heating Hot Water

• Chilled Water

• Condenser Water

• Glycol-Water

Hydronic Central Equipment

• Boilers (Fulton, Laars)

• Chillers (Carrier, York)

• Cooling Towers (BAC, Marley)

• Pumps (Bell and Gossett, Grundfos)

• Heat Exchangers (Danfoss)

Hydronic Terminal Equipment

• Coils (Greenheck)

• Unit Heaters (Modine)

• Fan Coil Units (Daikin, Carrier)

• Chilled Beams (York, Titus)


Step 3 | Learn building energy

analysis

You need to analyze indoor heat generation and heat

transfer through boundaries of buildings to determine

the type and size of the system required to maintain

the indoor design condition. The actual calculations are very complex and time

consuming to do by hand, and the standard practice is to use an energy analysis

software which you will learn in the next step.

However, before using a software for energy analysis, you need to learn about the

followings to be able to have the right input for your calculation by software:

• Indoor design conditions such as conditions for human comfort

• Outdoor design conditions: cooling, heating, evaporation, and dehumidification

• Ventilation for indoor air quality

• Methods of heat and mass transfer to and out of buildings

• Sources of heat generation inside buildings


Step 4 | Learn load calculation by a

software

As mentioned in Step 3, analyzing heat transfer to and

out of a building requires complex and time-

consuming calculations. That’s why using a software

for this task is necessary for accuracy and efficiency in the design.

Currently, Hourly Analysis Program (HAP) and Trane Trace 700 (or Trace 3D Plus) are

widely used in the United States for HVAC system design. Both of them can provide

calculations in Metric (SI) and US Customary (IP) units. You can also import weather data

for any location in the world to the software. So, you can use them for any commercial

project, anywhere in the world!

Check out these links to get familiar with them:

Trace 3D HAP

http://www.aeclearn.com/

https://www.trane.com/commercial/north-america/us/en/products-systems/design-and-analysis-tools/trane-design-tools.html

https://www.carrier.com/commercial/en/us/software/hvac-system-design/hourly-analysis-program/

https://www.trane.com/commercial/north-america/us/en/products-systems/design-and-analysis-tools/trane-design-tools.html

https://www.carrier.com/commercial/en/us/software/hvac-system-design/hourly-analysis-program/


Step 5 | Learn air and hydronic

distribution system design

You need to learn how to layout ducts, air terminals,

registers, diffusers, and grilles in enclosed spaces to

achieve proper air distribution inside the space. Also,

you need to learn how to calculate pressure drop in the ducting network to select the

right fan that provides the required airflow and pressure for your system.

Moreover, you need to learn how to layout pipes to provide heating hot water, chilled

water, or condenser water to HVAC equipment. You need to learn how to calculate

pressure drop in the piping network to select the right pump that provides the required

hydronic flow and pressure for your system.



Step 6 | Learn equipment selection

You need to be familiar with the process of selecting

the right equipment for the system that you design.

This is actually a very fun engineering exercise.

To select the right equipment, you need to gather all

the required data from your engineering analysis such as cooling load, heating load,

dehumidification load, air flow, water flow, pressure drop, available space, etc. and then

reach out to equipment manufacturers for a “selection”.

For a small equipment that costs less than $50,000, you can typically find the right

equipment on the manufacturer’s website. For a large equipment that can cost up to

$1,500,000, you need to contact a professional sales engineer to receive the right

selection.

Below is a list of some of the largest equipment manufacturers. Make sure to check out

their website and download equipment brochures, catalogs, and submittals.

Heating and cooling equipment

• Trane

• Daikin

• Carrier

Pumps for heating and cooling applications • Bell and Gossett

• Grundfos

Cooling towers • Baltimore Aircoil Company

• Marley (SPX)

Fans • Greenheck

• Twin City

Boilers • Fulton

• Laars


https://www.trane.com/commercial

https://www.daikin.com/

https://www.carrier.com/

https://bellgossett.com/

https://www.grundfos.com/

https://www.baltimoreaircoil.com/

https://spxcooling.com/

https://www.greenheck.com/

https://www.tcf.com/

https://www.fulton.com/

https://www.laars.com/


Step 7 | Learn sequence of

operation (system control) design

Design of HVAC systems, as any other complex system

design, includes control system design. Each

component in the HVAC system needs to operate in

coordination with other components. For example, an exhaust fan’s control damper

shall not close before the fan fully stops. Otherwise, the fan’s discharge duct gets over

pressurized, causing damage to the fan.

For simple systems such as a thermostatically controlled fans, the sequence of operation

is very easy to design. But for multi-component systems such as a DOAS with cooling,

heating, energy recovery, and dehumidification features the sequence of operation is

complex and requires study and coordination with the equipment’s manufacturer.

You need to learn how to design sequence of operation for HVAC systems. You can start

by learning about sequence of operation of simple systems such as split and packaged

heat pumps.



Step 8 | Learn AutoCAD Mechanical

AutoCAD is a software that Architect and Engineers

use to design variety of buildings and systems.

AutoCAD has been used for decades and continues

to be one of the major tools for all engineers who

work in the AEC industry. Autodesk, the company that created AutoCAD, releases a new

version of the software every year.

Since 2015, when companies around the world started using Revit and Building

Information Modelling (BIM) more often for new projects, AutoCAD has been mainly

used for existing building projects which are mostly in 2D. It is because Revit is a better

software for 3D design and BIM in new construction projects.

However, there are billions of constructed projects with only 2D drawings. Almost all of

these projects, which are now existing buildings and systems, need renovation in the

future. This means that AutoCAD will remain a key software for HVAC engineers for the

foreseeable future.

As an HVAC engineer, you only need to learn the basics of AutoCAD and its MEP toolset.

You do not need to spend weeks or even months to learn all the AutoCAD tools that you

will never use for HVAC design.



Step 9 | Learn Revit Mechanical

Revit is arguably the most popular software for new

building and facility modelling. Unlike AutoCAD, Revit

models are smart which help you to accurately and

efficiently model HVAC systems.

Revit is so widely used that almost all major HVAC equipment manufacturers offer free

Revit models of their equipment for you to use in your projects.

Revit has tools for Architectural, Structural, Interior, Electrical, and Mechanical

disciplines. Designing systems in Revit is an essential skill for all HVAC engineers, and

you definitely need to learn this skill. However, you only need to learn the basics of Revit

and its Mechanical design features. You don’t need to spend weeks or even months on

learning the tools that you will never use.



Step 10 | Aim high!

There are awesome companies that need HVAC

engineers for many exciting and critical applications.

For example, Google needs HVAC engineers to design

cooling systems for their data centers, Stantec needs

HVAC engineers to design HVAC systems for modern hospitals, and SpaceX needs HVAC

engineers to design HVAC systems for rockets.

Working as an HVAC engineer is a rewarding career with many opportunities to grow

professionally and financially, especially if you work in a great company. Here is a list of

some the best companies to work for as an HVAC engineer.

Stantec

AECOM

Arup

Jacobs

Parsons

Google

NASA Amazon

Microsoft Boeing

CH2M Arcadis

HDR

Fluor Corporation

Black & Veatch

SpaceX