HVAC Basics

SMACNA 65th Annual Convention Wailea, Maui, Hawaii

HVAC Systems Understanding The Basics Thomas E. Glavinich, D.E., P.E. The University of Kansas October 22, 2008

HVAC Systems - Understanding The Basics

Manual Objective

Provide an introduction to HVAC systems for project personnel and others needing a basic understanding of HVAC system operation and components.

Systems Approach To HVAC

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HVAC Contractor Defined HVAC contractor is the firm that is responsible for the installation for the complete HVAC system in accordance with the scope of work defined by the contract documents.

HVAC System Contractor Scope Of Services z

Air Distribution: – Sheet Metal – Air Distribution Equipment

z z z z z z

Piping Insulation Equipment (Wet) Water Treatment HVAC Controls Test & Balance

Self Perform Versus Subcontract

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HVAC System Contractor: Advantages z z

Establishes Firm As HVAC Expert Perform All Of CSI Division 23: – Greater Control Of Scope – Less Scope Overlaps & Gaps

z

Higher On Food Chain: – First Tier Subcontractor – Closer To $’s

z z z z

Potential Higher Profits Greater Control Of Schedule & Work Sequence More Project Opportunities More After-Installation Service Opportunities

HVAC System Contractor: Challenges z z z z z z

Increased Contract Size & Scope Subcontract Procurement & Contracting Subcontract Management Wet-Side Equipment Procurement Multiple Trade Management System Performance Risk

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HVAC Systems - Understanding The Basics

Target Audiences z

HVAC Contracting Firms: – – – – –

z

Project Managers Project Engineers Estimators Superintendents & Forepersons Others

Construction Programs – Colleges & Universities: – Engineering (Construction Emphasis) – Construction Science, Management, & Technology – Other Related Academic Programs

z

General Contractors & Construction Managers

HVAC Systems - Understanding The Basics

Intended To Complement HVAC Bid Specifications Manual z HVAC Systems Applications z SMACNA Guide Specifications z Other SMACNA Publications z

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2004 CSI MasterFormatTM

Division 23 – HVAC CSI Level 2 Content 23 00 00 23 10 00 23 20 00 23 30 00 23 40 00 23 50 00 23 60 00 23 70 00 23 80 00

HVAC General Requirements Facility Fuel Systems HVAC Piping & Pumps HVAC Air Distribution HVAC Air Cleaning Devices Central Heating Equipment Central Cooling Equipment Central HVAC Equipment Decentralized HVAC Equipment

HVAC Systems Applications I II III IV V VI VII VIII IX X XI XII XIII XIV

Introduction Basic HVAC Systems HVAC Control Systems Multizone Systems Dual-Duct Systems Terminal Reheat Systems Variable Air Volume Systems Induction & Induction Reheat Systems Special Applications Hydronic Systems Unitary & Heat Pump Systems Cooling/Refrigerant Systems Hydronic Heat Recovery Systems Engineering Data, Tables & Charts

Manual Currently Being Updated

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HVAC Systems: Understanding The Basics

How Will This Manual Be Used? z Chapter

Education Program z Self Study z Reference z Text: Primary Or Supplemental z Combination

HVAC Systems: Understanding The Basics

Chapter Outline I II III IV V VI VII VIII IX X

Introduction To HVAC Systems Properties Of Moist Air HVAC System Basics Unitary HVAC Systems Central Heating Equipment Central Cooling Equipment Hydronic Distribution Systems Air Distribution Systems Central HVAC Systems Control Systems

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HVAC Systems: Understanding The Basics

Chapter I - Intro To HVAC Systems 1.1 1.2 1.3 1.4 1.5 1.6

Introduction What Is An HVAC System? Why Do Buildings Need HVAC? A Brief History Of HVAC Systems HVAC Systems & 21st Century Buildings Overview Of This Manual

HVAC Systems: Understanding The Basics

Chapter II - Properties Of Moist Air 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13

Introduction Air Chemistry Air Temperature Air Humidity Evaporation & Condensation Moist Air Properties Psychrometry Heat Transfer Methods Heat Transfer Units Heat Transfer Media Moist Air Energy Content Simple Space Conditioning Processes Practical Space Conditioning Processes

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Air Temperature z What

Is Temperature? z Temperature Scales z Temperature Measurement

Air Humidity z What

Is Humidity? z Humidity Scales z Humidity Measurement

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Psychrometric Chart

Moist Air Physical Properties z Dry-Bulb

(DB) Temperature z Wet-Bulb (WB) Temperature z Percent Relative Humidity z Humidity Ratio z Dew Point Temperature z Air Specific Volume

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Moist Air Energy Content z Sensible

Heat z Latent Heat z Enthalpy

Basic Space Conditioning Processes z z z z z z z z

Sensible Cooling Sensible Heating Humidifying Dehumidifying Cooling & Dehumidifying Heating & Humidifying Chemical Dehumidifying Evaporative Cooling

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Simple Space Conditioning Processes

HVAC Systems: Understanding The Basics

Chapter III - HVAC System Basics 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15

Introduction HVAC System Purpose HVAC Zones & Spaces Airflow Defined Four Variables The Impact Human Comfort Defining Human Comfort Indoor Air Quality HVAC System Energy Use HVAC System Operation Basic HVAC System Mechanical Elements HVAC Controls Space Conditioning Methods Used By HVAC Systems HVAC Sys Categorized By Primary Heat Transfer Media HVAC System Space Conditioning Methods & Categories HVAC System Equipment Location & Heat Transport

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Four Variables That Affect Human Thermal Comfort Temperature z Thermal Radiation z Humidity z Air Speed z

American Society of Heating, Refrigerating, and AirConditioning Engineers, Thermal Environmental Conditions for Human Occupancy, ASHRAE 55-2004.

ASHRAE Comfort Zones

American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Thermal Environmental Conditions for Human Occupancy, ASHRAE 55-2004.

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HVAC System Energy Use z HVAC

System Energy Use z ASHRAE/IESNA Standard 90.1 z Energy Codes & Standards z Green Buildings & HVAC Energy Use

Basic HVAC System Elements z Thermal

Conditioner z Moisture Controller z Air Mover z Air Cleaner

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Basic HVAC System Elements

Space Conditioning Methods z Constant

Air Volume - Variable Temperature z Variable Air Volume - Constant Temperature z Variable Air Volume - Variable Temperature

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HVAC Systems: Understanding The Basics

Section 3.13 - Primary Heat Xfer z z z z z

All-Air HVAC Systems Air-Hydronic HVAC Systems All-Hydronic HVAC Systems Direct Refrigerant HVAC Systems Hybrid HVAC Systems

All-Air HVAC System

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Air-Hydronic HVAC System

All-Hydronic HVAC System

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HVAC Systems: Understanding The Basics

Chapter IV - Unitary HVAC Systems 4.1 4.2 4.3 4.4 4.5 4.6

Introduction Unitary HVAC Systems Characteristics & Use Refrigeration Defined The Refrigeration Cycle Direct Expansion Refrigeration Systems Unitary HVAC System Types

Refrigeration Cycle

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HVAC Systems: Understanding The Basics

Section 4.5.2 Six Primary DX System Components z Compressor z Condenser

Coil z Regulator Valve z Evaporator Coil z Refrigerant Piping z Controls

HVAC Systems: Understanding The Basics

Section 4.6 - Unitary HVAC Systems z z z z z z z

Packaged Terminal HVAC Units Room Air Conditioners Self-Contained Air Conditioners Computer-Room Air-Conditioners Split-System Air-Conditioners Air-Source Unitary Heat Pumps Water-Source Unitary Heat Pumps

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HVAC Systems: Understanding The Basics

Chapter V - Central Heating Equipment 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12

Introduction Furnaces Boilers Boiler Sizing Boiler Construction Electric Boilers Condensing Boilers Boiler Auxiliary Equipment Boiler Controls Boiler Water Treatment Solar Energy Heating Systems Combined Heat & Power

HVAC Systems: Understanding The Basics

Chapter VI - Central Cooling Equipment 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10

Introduction Central Cooling Plant Operation & Components Chiller Purpose Refrigeration Cycle Refrigerant Motor-Compressor Units Mech Compressor Operation & Characteristics Absorption Chillers Cooling Towers Evaporative Cooling Systems

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Central Cooling Plant Schematic Diagram

HVAC Systems: Understanding The Basics

Chapter VII - Hydronic Distribution Sys 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9

Introduction Hot Water Distribution System Operation Chilled Water Distribution System Operation Hydronic Distribution System Operating Temps Hydronic Distribution System Arrangements Multi-Loop Hydronic Distribution System Hydronic Distribution System Heat Xfer Mode Convection Terminal Units Hydronic Radiant Heat

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HVAC Systems: Understanding The Basics

Section 7.5 Hydronic Dist Sys Arrangements z One-Pipe

System z Two-Pipe System z Three-Pipe System z Four-Pipe System z Summer-Winter System

Two-Pipe Hydronic Distribution (Direct Return)

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HVAC Systems: Understanding The Basics

Section 7.8 Convection Terminal Units z z z z z z z z z

Air-Coil Units Fan-Coil Units Induction Units Unit Ventilators Radiators Finned-Tube Radiation Heaters Valence Units Convectors Unit Heaters

HVAC Systems: Understanding The Basics

Chapter VIII - Air Dist Systems 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15

Introduction Air Distribution System Purpose Air Distribution System Components Fans Air Handling Units Air Ducts & Plenums VAV Terminal Units Air Outlets & Inlets Air Distribution System Operation Air Distribution System Operating Point Air Distribution System Dynamics System Operating Point & Fan Speed Variable Frequency Drives Air Cleaning Devices Testing, Adjusting, & Balancing

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HVAC Systems: Understanding The Basics

Chapter IX - Central HVAC Sys 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8

Introduction Central HVAC Subsystems VAV System Description VAV System Operation VAV Terminal Operation HVAC Systems Incorporating VAV Constant Volume HVAC Systems VAV Versus Constant-Volume

Central HVAC System Block Diagram

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Basic Single-Zone Cooling Only VAV System

HVAC Systems: Understanding The Basics

Chapter X - Control Systems 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 10.10

Introduction Control System Purpose Control System Types Control System Components Thermostat: Simple Control System Sensors Controllers Controlled Devices Building Automation & Control Systems Open-Architecture Control Systems

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HVAC Systems: Understanding The Basics

Appendices A B C D

HVAC Glossary HVAC MasterFormatTM Outline HVAC References & Resources Chapter Education Program

Questions?

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