Heating, ventilation and air conditioning engineering and design

(1)

Theses

Thesis/Dissertation Collections

1990

Heating, ventilation and air conditioning

engineering and design

Kurt Kuegler

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Abstract

The

object of

this

Design

Project

was

to

learn

and

demonstrate

the

engineering

and

design

of

Heating,

Ventilation

and

Air

Conditioning

systems.

This

was

done

in

two

parts.

The

first

part

was

the

design

project.

The

design

project consisted of

designing

the

heating,

ventilation and

air-conditioning

systems

for

a

three

story

office

building.

The

second part

discusses

the

theoretical

aspects of

heating,

ventilation and

air-conditioning

systems

(4)

Table

of

Contents

Part

1

1.

Design

Proposal

2

1.1

Proposal

2

1.2

The

Building

2

1.3

The

Choice

of

Building

Systems

2

1.4

Depth

of

Analysis

and

Design

3

2.

Building

Loads

4

2.1

Method

Used

To

Determine

Loads

4

2.2

Building

Input

10

2.3

Determining

Building

Loads

13

2.4

Discussion

of

Load

Calculations

14

3.

Building

Systems

16

3.1

General

16

3.2

Variable

Air

Volume

System

(VAV)

16

3.3

Water

Source

Heat

Pump

System

17

3.4

Ventilation

System

17

3.5

Exhaust

System

18

3.6

Water

Loop

System,

Boiler,

Fluid

Cooler,

Air

Separator,

Compression

Tank

and

Pumps

18

3.7

Controls

and

Control

Sequence

19

4.

Psychrometrics

22

4.1

Variable

Air

Volume

System

22

4.2

Heat

Pump

System

34

5.

Components

50

5.1

Variable

Air

Volume

System

50

5.2

Heat

Pump

System

53

5.3

Ventilation

System

54

5.4

Exhaust

System

56

(5)

Part

2

6.

Thermodynamics

66

6.1

Basic

Concepts

and

Definitions

66

6.2

First

Law

of

Thermodynamics

69

6.3

Second

Law

of

Thermodynamics

72

7.

Fluid

Flow

83

7.1

Eulerian

Integral

approach

83

7.2

Basic

Equations

in

Integral

form

for

a

Control

Volume

83

7.3

Bernoulli

Equation

(incompressible

invisid

flow)

-along

a stream

line:

84

7.4

Static,

Stagnation,

and

Dynamic

Pressures

84

7.5

Unsteady

Bernoulli

Equation

86

7.6

Internal

Incompressible

Viscous

Flow

86

7.7

Calculation

of

Head

Loss

in

Piping

Systems

87

7.8

Static

Pressure

Loss

in

Air

Duct

Systems

94

8.

Heat

Transfer

101

8.1

Conduction

101

8.2

Convection

105

8.3

Radiation

106

9.

Mass

Transfer

111

9.1

Molecular

diffusion

111

9.2

Convection

of

Mass

114

10.

Psychrometrics

118

10.1

Moist

Air

and

the

Standard

Atmosphere

118

10.2

Fundamental

Parameters

119

10.4

Classic

Moist

Air

Processes

125

10.5

The

Goff

and

Grath

Tables

for

Moist

Air

133

11.

Comfort

and

Health

136

11.1

Thermal

Interchanges

Between

People

and

Their

Environments

136

11.2

Comfort

Conditions

141

11.3

Indoor

Climate

and

Health

142

11.4

Control

of

Indoor

Air

Quality

143

(6)

12.2

Convection

150

12.3

Thermal

Radiation

150

12.4

Overall

Heat

Transfer

Coefficient

(U)

155

13.

Solar

Radiation

165

13.1

The

motion of

the

Earth

About

the

Sun

165

13.2

Time

167

13.3

Solar

Angles

168

13.4

Solar

Irradiation

172

14.

Space

Heat

Load

178

14.1

Outdoor

Design

Conditions

179

14.2

Indoor

Design

Conditions

179

14.3

Calculation

of

Heat

Losses

179

14.4

Heat

Losses

From Air

Ducts

192

14.5

Auxiliary

Heat

Sources

192

14.6

Intermittently

Heated

Structures

192

14.7

Estimating

Fuel

Requirements

192

15.

The

Cooling

Load

195

15.1

Heat

Gain,

Cooling

Load,

and

Heat

Extraction

Rate

196

15.2

Outdoor

and

Indoor

Design

Conditions

201

15.3

The

CLTD

Method

201

15.4

Cooling

Load-

External

Sources

203

15.5

Cooling

Load

-Internal

Sources

222

15.6

Heat

Gain

From

Infiltration

and

Outdoor

Ventilation

Air

228

15.7

Summation

of

Heat

Gains

and

Cooling

Loads

228

15.8

Cooling

Loads

by

the

Transfer

Function

Method

228

15.9

Heat

Extraction

Rate

and

Room

Temperature

238

16.

Water

Piping

Systems

242

16.1

The

Conventional

One-Pipe

System

243

16.2

The

Two-Pipe

Direct-Return

System

244

16.3

The

Two-Pipe

Reverse-Return

System

245

16.4

The

Three-Pipe

Arrangement

246

16.5

Four-Pipe

Arrangement

247

16.6

Pipe

Expansion

247

16.7

Pipe

Anchors

and

Supports

249

16.8

Pumps

250

16.9

Special

Fittings

and

Devices

Required

in

(7)

17.

Fans

and

Building

Air

Distribution

256

17.1

Fans

256

17.2

Fan

Performance

258

17.3

Fan

Selection

265

17.4

Fan

Installation

267

17.5

Fans

and

Variable

Air

Volume

Systems

268

17.6

Air

Flow

In

Ducts

and

Fittings

271

17.7

Duct

Design

-General

Considerations

271

17.8

Design

of

Low

Velocity

Duct

Systems

274

17.9

Turning

Vanes

and

Dampers

27 6

17.10

High

Velocity

Duct

Design

279

18.

Air-Conditioning

and

Heating

Systems

282

18.1

All-Air

Systems

282

18.2

All-Water

Systems

302

18.3

Air-and-Water

Systems

305

18.4

Heat

Pumps

-Applied

308

19.

Special

Topics

322

19.1

Noise

and

Vibration

322

19.2

Codes

323

19.3

Controls

323

Refernces

324

Appendix

20.

Calculations

320

20.1

Load

Calculation

Sample

Output

321

20.2

Piping

System

322

21.

Drawings

323

21.1

Architectural

324

21.2

Mechanical

325

(8)

List

of

Tables

Table

4-1,

Property

Chart

-VAV

Cooling

Table

4-2,

First

Law

Chart

-VAV

Cooling

Table

4-3,

Property

Chart

-Heat

Pump

Cooling

Table

4-4,

First

Law

Chart

-Heat

Pump Cooling

Table

4-5,

Property

Chart

-Heat

Pump Heating

Table

4-6,

First

Law

Chart

-Heat

Pump Heating

Table

5-1,

VAV

Boxes

Table

5-2,

Diffusers

Table

5-3,

Heat

Pumps

Table

5-4,

Ventilation

Fans

Table

5-5,

Exhaust

Fans

56

Table

7-1,

Minor

Loss

Coefficients

for

Pipe

Entrances

Table

7-2,

Loss

Coefficients

for

Gradual

Contractions

Round

and

Rectangular

Ducts

Table

7-3,

Representative

Dimensionaless

Equivalent

Lengths

(Le/D)

for

Valves

and

Fittings

Table

8-1,

Low-temperature

Emissivity

and

High-temperature

Absorptivity

of

Various

Surfaces

Table

8-2,

Spectral

Transmittance

of

Glass

Table

10-1,

Constants

A,

B

and

C

(standard

atmospheric

pressure)

Table

12-1,

Table

12-2,

Table

12-3,

Table

12-4,

Table

12-5,

Table

12-6,

Table

12-7,

Table

12-8,

Thermal

Resistances

for

Some

Steady

state

Conduction

Problems

Thermal

Properties

of

Building

and

Insulating

Materials

at a

Mean

Temperature

of

75F

(English

Units)

Surface

Unit

Conductances

and

Unit

Resistance

for

Air

Reflectance

and

Emittance

of

Various

Surfaces

and

Effective

Emittance

of

Air

Spaces

Unit

Thermal

Resistance

of a

Plane

3/4

inch

Air

Space

Unit

Thermal

Resistance

of a

Plane

3.5

inch

Air

Space

Unit

Thermal

Resistance

of

Plane

Horizontal

Air

Spaces

With

Heat

Flow

Downward,

Temperature

Difference

10

Deg

F

Coefficients

of

Transmission

U

of

Frame

Walls,

BTU/(hr

ft2

F)

(9)

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12

Table

12-21

9,

Coefficients

of

Transmission

U

of

Solid

Masonry

Walls,

BTU/(hr

ft2

F)

10,

Coefficients

of

Transmission

U

of

Masonry Cavity Walls,

BTU/(hr

ft2

F)

Coefficients

of

Transmission

U

of

Ceilings

and

Floors,

BTU/(hr

ft2

F)

Coefficients

of

Transmission

U

of

Flat

Built

Up Roofs,

BTU/(hr

ft2

F)

Coefficients

of

Transmission

U

of

Pitched

Roofs,

BTU/(hr

ft2

F)

Overall

Coefficients

of

Heat

Transmission

(U-Factor)

of

Windows

and

Skylights,

BTU/(hr

ft2

F)

Adjustment

Factors

for

Coefficients

U

of

Table

12-14,

BTU/(hr

ft2

F)

Coefficients

of

Transmission

U

of

Slab

Doors,

BTU/(hr

ft2

F)

17,

Heat

Loss

Through

Basement

Floors

(for

Floors

More

Than

3

ft

Below

Grade)

18,

Heat

Loss

Rate

for

Below-Grade

Walls

With

Insulation

on

Inside

Surface

19,

Heat

Loss

of

Concrete

Floors

Ltss

Than

3

ft

Below

Grade

Floor

Heat

Loss

for

Concrete

Slabs

With

Embedded

Warm

Air

Perimeter

Heating

Ducts

(Per

Unit

Length

of

Heated

Edge)

Transmission

Coefficients

U

For

Horizontal

Bare

Steel

Pipes

and

Flat

Surfaces,

BTU/(hr

ft2

F)

-11, -12, -13, -14, -15. -16, 20

Table

13-1,

The

Equation

of

Time

Table

13-2,

Extraterrestrial

Solar

Radiation

and

for

Twenty-First

Day

of

Each

Month,

Base

Year

1964

Table

14-1,

Air

Changes

Taking

Place

Under

Average

Conditions

in

Residences.

Exclusive

of

Air

Provided

for

Ventilation

Pressure

Coefficients

for

a

Rectangular

Building

Table

14-3,

Window

Classification

Residential-Type

Door

Classification

Curtain

Wall

Classification

Table

14-2,

Table

14-4,

Table

14-5.

157

158

159

160

161

162

163

164

168

175

182

184

188

189

Table

15-1,

Cooling

Load

Temperature

Differences

for

Calculating

Cooling

Load

From

Flat

Roofs

205

Table

15-2,

Cooling

Load

Temperature

Differences

for

(10)

Table

15-7

Table

15-10

Table

15

Table

15

-11 -12

Table

15-3,

CLTD

Correction

For

Latitude

and

Month

Applied

to Walls

and

Roofs,

North

Latitudes

207

Table

15-4,

Roof

Construction

Code

208

Table

15-5,

Wall

Construction

Group

Description

209

Table

15-6,

Thermal

Properties

and

Code

Numbers

of

Layers

Used

in Calculations

of

Coefficients

for

Roof

and

Wall

210

Cooling

Load

Temperature

Difference

for

Conduction

Though

Glass

and

Conduction

Through

Doors

212

Table

15-8,

Shading

Coefficient

for

Single

Glass

and

Insulating

Glass

213

Table

15-9,

Shading

Coefficients

For

Single

Glass

With

Indoor

Shading

by

Venetian

Blinds

and

Roller

Shades

215

Shading

Coefficients

For

Insulating

Glass

With

Indoor

Shading

by

Venetian

Blinds

and

Roller

Shades

216

Shading

Coefficients

For

Single

and

Insulating

Glass

With

Draperies

218

Maximum

Solar

Heat

Gain

Factor

For

Externally

Shaded

Glass,

BTU/(HR-FT2)

(Based

on

Ground

Reflectance

of .2)

219

Maximum

Solar

Heat

Gain

Factor,

BTU/(HR-FT2),

for

Sunlit

Glass,

North

Latitudes

220

Cooling

Load

Factors

for

Glass

Without

Interior

Shading,

North

Latitudes

221

Table

15-15,

Cooling

Load

Factors

for

Glass

With

Interior

Shading,

North

Latitudes

222

Table

15-16,

Rates

of

Heat

Gain

from

Occupants

of

Conditioned

Spaces

223

Table

15-17,

Sensible

Heat

Cooling

Load

Factors

for

People

224

Table

15-18,

Cooling

Load

Factors

When

Lights

are on

for

10

Hours

225

Table

15-19,

"a"

Classification

for

Lights

226

Table

15-20,

"b"

Classification

for

Lights

227

Table

15-21,

Sensible

Heat

Cooling

Load

Factors

for

Appliances-Unhooded

227

Table

15-22,

Transfer

Function

Coefficients

for

Exterior

Walls

(Time

Interval

=

1.0

hr)

231

Table

15-23,

Transfer

Function

Coefficients

for

Roofs

(Time

Interval

=

1.0

hr)

232

Table

15-24,

Transfer

Function

Coefficients

for

Interior

Partitions,

Floors,

and

Ceilings

(Time

Interval

=

1.0

hr)

233

Table

15-25,

Percentage

of

the

Daily

Range

234

Table

15-13

(11)

Air

Circulation

Rates

and

Envelope

Construction

236

Table

15-28,

Normalized

Coefficients

of

the

Room

Air

Transfer

Function

239

Table

16-1,

Linear

Expansion

of

Pipe

in

Inches

per

100

Feet

248

Table

17-1,

Comparison

of

Centrifugal

Fan

Types

262

Table

17-2,

Pressure-Capacity

Table

for

a

Forward-curved

Blade

Fan

266

Table

17-3,

Recommended

Maximum

Duct

Velocities

for

High

Velocity

Systems

272

Table

17-4,

Recommended

and

Maximum

Duct

Velocities

for

Low

Velocity

Systems

273

Table

18-1,

Common

Heat

Pump

Types

309

(12)

List

of

Figures

Figure

2-1,

Space

Input

Sheet

6

Figure

2-2,

Zone

Input

Sheet

9

Figure

4-1,

Floor

2,

VAV

System

Diagram,

Maximum

Cooling

23

Figure

4-2,

Floor

2,

VAV

Psychrometric

Chart,

Maximum

Cooling

26

Figure

4-3,

Floor

2,

VAV

System

Diagram,

Morning

Warm-up

31

Figure

4-4,

Floor

2,

VAV

Psychrometric

Chart,

Morning Warm-up

32

Figure

4-5,

Floor

2,

Heat

Pump

System

Diagram,

Maximum

Cooling

35

Figure

4-6,

Floor

2,

Heat

Pump

Psychrometric

Chart,

Maximum

Cooling

38

Figure

4-7,

Floor

2,

Heat

Pump

System

Diagram,

Morning

Warm-up

41

Figure

4-8,

Floor

2,

Heat

Pump

System

Diagram,

Maximum

Heating

44

Figure

4-9,

Floor

2,

Heat

Pump

Psychrometric

Chart,

Maximum

Heating

46

Figure

5-1,

Ventilation

Flow

Diagram

55

Figure

5-2,

Exhaust

Flow

Diagram

57

Figure

5-3,

Piping

Diagram

59

Figure

6-1,

Thermodynamic

System

70

Figure

6-2,

Carnot

Cycle

-Temperature

Versus

Entropy

Diagram

75

Figure

6-3,

Vapor

Compression

Refrigeration

System

76

Figure

6-4,

Vapor

Compression

Refrigeration

Cycle,

Pressure

Versus

Enthalpy

Diagram

77

Figure

6-5,

Vapor

Compression

Refrigeration

Cycle,

Temperature

Versus

Entropy

Diagram

77

Figure

6-7,

Vapor

Compression

Refrigeration

Cycle,

Pressure

Versus

Specific

Volume

78

Figure

6-8,

Compressor

78

Figure

6-9,

Condenser

79

Figure

6-10,

Throttle

80

Figure

6-11,

Evaporator

81

Figure

7-1,

Wall

Pressure

Tap

85

Figure

7-2,

Static

Pressure

Probe

85

Figure

7-3,

Stagnation

Pressure

Gauge

85

Figure

7-4,

Entrance

Length

and

Fully

Developed

Flow

87

Figure

7-5,

Friction

Factor

for

Fully

Developed

Flow

(13)

Figure

7-6,

Relative

Roughness

Values

for

Pipes

of

Common

Engineering

Materials

89

Figure

7-7,

Loss

Coefficients

for

Flow

through

Sudden

Area

Changes

91

Figure

7-8,

Pressure

Recovery

Data

for

Conical

Diffusers

with

Fully

Developed

Turbulent

Pipe

Flow

at

Inlet

92

Figure

7-9,

Representative

Resistance

values

(Le/D)

for

(a)

90*

Pipe

Bends

and

Flanged

Elbows,

and

(b)

Miter

Bends

93

Figure

7-10,

Converging

and

Diverging

Flows

99

Figure

8-1,

Conduction

Through

a

Single

Material

101

Figure

8-2,

One

Dimensional

System

in

Rectangular

Coordinates

102

Figure

8-3,

Volume

Element

in

Cylindrical

Coordinates

103

Figure

8-4,

One

Dimensional

System

103

Figure

8-5,

Materials

in

Series

104

Figure

8-6,

Composite

Wall

in

Series/Parallel

Arrangement

105

Figure

8-7,

Variation

of

Normal

Spectral

Emissivity

with

Wavelength

for

Several

Surfaces

108

Figure

8-8,

Variation

of

the

Total

Normal

Emissivity

en

With

Temperature

109

Figure

8-9,

Variation

of

Normal

Spectral

Reflectivity

P0n and

Normal

SpectralAbsorptivity

ot0n

With

Wavelength

for

Various

opaque

Surfaces

109

Figure

9-1,

Mass

Transfer

for

an

External

Flow

115

Figure

9-2,

Mass

Transfer

for

an

Internal

Flow

116

Figure

9-3,

Mass

Transfer

for

turbulent

Flow

Regions

117

Figure

10-1,

Adiabatic

Saturation

Device

123

Figure

10-2,

Psychrometric

Chart

124

Figure

10-3,

Heating

or

Cooling

Device

125

Figure

10-4,

Sensible

Heating

and

Cooling

126

Figure

10-5,

Cooling

and

Dehumidif ying

Process

127

Figure

10-6,

Heating

and

humidifying

Process

128

Figure

10-7,

Heating

and

Humidifying

Device

129

Figure

10-8,

Humidif

ication

Process

Without

Heat

Transfer

130

Figure

10-9,

Adiabatic

Mixing

Device

131

Figure

10-10,

Adiabatic

Mixing

Process

131

Figure

10-11,

Error

of

Perfect

Gas

Relations

in

calculation of

humidity

ratio,

enthalpy,

and volume of

standard

air

(14)

Figure

13--1

Figure

13--2

Figure

13--3

Figure

13--4

Figure

13--5

Figure

13--6

Figure

13-7

Figure

11-1,

Acceptable

Ranges

of

Operative

Temperature

and

Humidity

for

Persons

Clothed

in

Typical

Summer

and

Winter

clothing,

at

Light,

Mainly

Sedentary,

Activity

141

The

Effect

of

the

Earth's

Tilt

and

Rotation

About

the

Sun

166

Latitude,

Hour

Angle,

and

Sun's

Declination

168

The

Solar

Altitude,

Zenith

Angle,

and

Azimuth

Angle

170

Wall

Solar

Azimuth,

Wall

Azimuth,

Angle

of

Tilt

for

an

Arbitrary

Tilt

171

Shading

of

Window

Set

Back

From

Plane

of a

Building

172

Spectral

Distribution

of

Direct

Solar

Irradiation

at

Normal

Incidence

During

Clear

Days

174

Conversion

of

Horizontal

Insolation

to

Insolation

on a

Tilted

Surface

177

Heat

Loss

Work

Sheet

180

Pressure

Difference

Due

to

Stack

Effect

186

Curtain

Wall

Infiltration

for

One

Room

or

One

Floor

187

Window

and

Residential

Type

Door

Infiltration

Characteristics

187

Infiltration

Through

Closed

Swinging

Door

Cracks

188

Infiltration

for

Storm-Prime

Combination

Windows

190

Swinging

Door

Characteristics

With

Traffic

190

Flow

Coefficient

Dependence

on

Traffic

Rate

191

Correction

Factor

CD

193

Schematic

Relation

of

Heat

Gain

to

Cooling

Load

197

Actual

Cooling

Load

and

Solar

Heat

Gain

for

Light,

Medium,

and

Heavy

Construction

197

Distribution

of

Solar

Radiation

Falling

on

Clear

Plate

Glass

211

Indoor

Shading

Properties

of

Drapery

Fabrics

217

Cooling

Load

Worksheet

229

(15)

Figure

15-7,

Room

Air

Temperature

and

Heat

Extraction

Rates

for

Continuous

and

Intermittent

Operation

241

Figure

16-1,

Series

Loop

Heating

System

242

Figure

16-2,

Conventional

One-Pipe

System

243

Figure

16-3,

Two-Pipe

Direct-Return

System

245

Figure

16-4,

Two-Pipe

Reverse-Return

System

245

Figure

16-5,

Three-Pipe

System

246

Figure

16-6,

Four-Pipe

System

247

Figure.

16-7,

Common

Expansion

Joints

and

Expansion

Bends

249

Figure

17-1,

Exploded

View

of a

Centrifugal

Fan

257

Figure

17-2,

Axial

Flow

Fans

257

Figure

17-3,

Forward-tip

Fan

Characteristic

260

Figure

17-4,

Backward-tip

Fan

Characteristic

260

Figure

17-5,

Radial-tip

Fan

Characteristic

260

Figure

17-6,

Conventional

Curves

for

Backward-curved

Blade

Fan

261

Figure

17-7,

Performance

Data

for

a

Typical

Backward-curved

Blade

Fan

262

Figure

17-8,

Optimum Match

Between

System

and

Forward-curved

Blade

Fan

263

Figure

17-9,

Performance

Chart

Showing

Combination

of

Fan

and

System

264

Figure

17-10,

Comparison

of

Good

and

Poor

Fan

Connections

267

Figure

17-11,

Performance

Curves

Showing

Modified

Fan

Curve

268

Figure

17-12,

Variable

Inlet

Vane

Fan

in

a

Variable

Volume

System

270

Figure

17-13,

Variable

Inlet

Vane

Fan

in

a

Variable

Volume

System

271

Figure

17-14,

Typical

Use

of

Vanes

in

a

Rectangular

Duct

277

Figure

17-15,

Typical

Opposed

Blade

Damper

Assembly

278

Figure

17-16,

Combination

Turning

Vane

and

Damper

Assembly

27 8

Figure

18-1,

Single-Zone

System

285

Figure

18-2,

Single-Zone

System

-Psychrometric

Chart

286

Figure

18-3,

Reheat

System

287

Figure

18-4,

Reheat

System

-

Psychrometric

Chart

288

Figure

18-5,

Variable

Air

Volume

System

291

Figure

18-6,

Variable

Air

Volume

System

-Psychrometric

Chart

292

Figure

18-7,

Series

Arrangement

-Plan

View

298

Figure

18-8,

Parallel

Arrangement

-Plan

View

298

(16)

Figure

18-10,

Dual

Path

System

-

Psychrometric

Chart

301

Figure

18-11,

Typical

Fan

Coil

Unit

303

Figure

18-12,

Typical

Fan-Coil

Unit

Arrangements

303

Figure

18-13,

Air-Water

Induction

Unit

307

Figure

18-14,

Water-to-Water

Heat

Pump

System

311

Figure

18-15,

Air-to-Water

Single

Stage

Heat

Pump

313

Figure

18-16,

Air-to-Air

Heat

Pump

315

Figure

18-17,

Heat

Transfer

Heat

Pump

with

Double-Bundle

Condenser

316

Figure

18-18,

Heat

Transfer

System

with

Storage

Tank

317

Figure

18-19,

Multistage

(Cascade)

Heat

Transfer

System

318

Figure

18-20,

Closed

Loop

Solar

Heat

Pump

System

319

Figure

18-21,

Heat

Transfer

System

Using

(17)

Introduction

"By

the

end

of

the

19th

century

the

concept

of

central

heating

was

fairly

well

developed,

and

early

in

the

twentieth

century

cooling

for

comfort

got

its

starf'l.

Since

this

time

there

have

been

many

developments

to

bring

the

industry

to

the

level

of

design

it

has

now.

The

greatest

developments

have

been

made

in

the

detailed

analytical

methods

needed

for

the

design

of

large

systems.

The

most

recent

major

development

has

been

in

designing

heating,

ventilation

and air

conditioning

systems

through

the

use of

computers.

The

Heating

Ventilation

_and

Air

Conditioning

field

is

very

large

in

engineering

and

it

has

grown

through

the

input

of

thousand

of

engineers,

their

names

are

too

numerous

to

list.

This

Design

Project

is

broken

down

into

two

parts.

The

first

part

is

the

design

of a

heating

ventilation

_and

air-conditioning

system

for

a

three

story

office

building.

The

second

part

discusses

the

theoretical

aspect

of

heating

ventilation

and air

conditioning

engineering

_and

design.

1

Faye

C.

Mc

.

Quiston

and

Jerald

D.

Parker.

Heating

Ventilation

and

Air

Conditioning

Analysis

and

Design.

(18)

(19)

The

purpose of

the

design

project was

to

demonstrate

the

concepts

and

theory

of

heating,

ventilation and

air-conditioning

design.

This

was

done

by

designing

the

heating,

ventilation and

air-conditioning

systems

for

a

three

story

office

building.

The

design

used

many

different

types

of

systems and combinations of systems.

1.2

The

Building

The

building

used

in

this

design

was a

three

story

office

building

approximately

160'

by

100' or

48,000

square

feet.

The

building

was

designed

for

tenant

fit

up.

Tenant

fit

up

means

that

the

office space

floor

area

is

open and

the

tenant

will

install

his

own walls

to

create

the

tenant's

desired

office area.

The

building's

main entrance

is

two

stories

high

and

leads

into

the

main corridor.

This

corridor

is

the

same

for

the

other

two

floors.

The

building's

exterior wall area

is

approximately

40%

glass and

60%

brick.

The

building

has

no

basement,

it

is

slab on

grade.

The

roof of

the

building

is

metal

deck

with a

foam/roof

membrane covering.

Further

details

of

the

building

(wall

and roof

sections)

can

be

seen on

the

plans .

(20)

versus

function.

The

systems

were chosen

to

demonstrate

the

knowledge

and

understanding

for

the

HVAC

field.

The

system

in

the

building

uses a water

loop

heat

transfer

system,

using

Water-to-Air

Unitary

heat

pumps

for

the

building

perimeter and a

Variable

Air

Volume

system with central electric

heat

for

the

interior.

The

system uses a gas

boiler

and a

fluid

cooler

to

maintain

the

water

temperature

in

the

water

loop.

A

more

detailed

discussion

of

these

systems

is

given

in

the

chapter

"Discussion

of

Building

Systems".

1.4

Depth

of

Analysis

and

Design

The

heating

and

cooling

load

analysis was

performed

in

detail.

The

psychrometric analysis and

design

portion of

the

project was performed

in

partial

detail.

What

is

meant

by

this

is

that

the

psychrometric

analysis,

duct

static pressure

calculations and water

loop

system static pressure

calculations were

only

performed

in

detail

for

the

second

floor

of

this

building.

This

was

done

because

these

calculations would

be

redundant work

if

preformed

for

the

other

two

floors.

The

basis

of

this

design

project

is

to

show

the

basic

understanding

of

(21)

A

computer

program

was used

to

determine

the

heating

and

cooling

loads

for

the

building.

The

computer program used was

the

Hourly

Analysis

Program

by

Carrier.

This

program

used separate methods

for

determining

the

heating

and

cooling

loads.

2.1.1

Heating

Design

Load

Analysis

-The

"

Design

Point"

analysis

technique

was used

to

determine

the

heating

loads.

A

design

point was used

because

usually

the

coldest part of

the

year

is

at night

at a specific

temperature.

At

this

point

the

program analyzes

transmission,

ventilation and

infiltration

loads.

This

point selected

is

not

associated with

any

particular month or

hour.

2.1.2

Cooling

Design

Load

Analysis

-Cooling

loads

have

to

take

into

consideration of

the

loads

caused

by

thermal

storage and solar

heat

gain.

Therefor,

an

hour

by

hour

analysis was preformed

to

compute

the

cooling

loads.

From

this

analysis

the

maximum

cooling

load

was

determined.

Often

this

maximum

cooling

load

does

not correspond

to

the

maximum outdoor

temperature.

2.1.3

Weather

Data

-

Weather

data

for

the

cooling

analysis was given

by

a pair of

hourly

wet

bulb

(22)

empirical method and represents

1%

cooling

design

conditions.

For

design

heating

load

calculations,

the

99%

Winter

design

point was

used.

The

program contains pre-stored weather

data

of

this

type

for

over

500

cities worldwide.

2.1.4

Schedule

Data

-Schedules

were used

to

give

hourly

characteristics of

internal

heat

gains.

Such

characteristics were

lighting,

occupancy,

miscellaneous

internal

loads

and equipment

operations .

2.1.5

Define

Spaces

-Spaces

in

a

building

are areas

which

have

load

related elements

like

walls,

glass and ceilings.

Usually

spaces are

individual

rooms or

for

vary

large

rooms

there

could

be

many

spaces.

For

each space

there

is

a

space

input

sheet

that

must

be

filled

out so

its

data

can

be

entered

into

the

computer.

An

example of

this

sheet

is

on

the

following

two

(23)

COMPLEX SPACE INPUT

SHEET

SPACE NAME

PAGE 1 OF 2

WALL INFORMATION

(NUMBER

OF

WALL

TYPES

=

)

Weight

(H, M,

L

or

Ib/sqft)

Ext Color

(D, M, L)

U-Value

(BTU/hr/sqft/F)

Wall Type

1

Wall

Type

2

Wall Type 3

NET WALL AREAS

(SOFT)

Exposure

Wall

Type

1

Wall Type 2

Wall Type 3

Northeast

East

Southeast

South

Southwest

West

Northwest

North

ROOF INFORMATION

(NUMBER

OF

ROOF

TYPES

=

)

Weight

(H, M,

L

or

Ib/sqft)

Ext Color

(D,

M, L)

U-Value

(BTU/hr/sqft/F)

Area

(sqft)

Roof Type 1

Roof Type 2

Roof Type 3

GLASS

INFORMATION

(NUMBER OF

GLASS TYPES

=

)

U-Value

(BTU/hr/sqft/F)

Glass

Factor

Internal

Shades?

Glass Type

1

Glass Type

2

Glass Type

3

EXTERNAL

SHADING

INFORMATION

Window

Height

()

Window Width

()

Reveal Depth

(In)

Overhang

Height

(In)

Overhang

Extension

(In)

Fin

Separation

(In)

Fin

Extension

(In)

Shade

1

Shade

2

Shade

3

Glass Type 1

Glass Type 2

Glass

Type 3

(24)

INTERNAL LOADS

SPACE

DATA

:

Floor

Area

PEOPLE

: sqft/person

Schedule

No.

Sensible Gain

LIGHTING

:

W/sqfl

Schedule

No.

Fixture Type

OTHER ELECTRIC

:

W/sqft

Schedule

No.

MISC

SENSIBLE

:

Load

MISC LATENT

:

Load

sqft

Building

Wt.

Total People

Activity

Level

Latent

Gain

Total Watts

Wattage Mult

Total Watts

BTU/hr

Schedule No.

BTU/hr

Schedule No.

PARTITIONS, INFILTRATION,

GROUND

PARTITIONS

(Next to Unconditioned

Spaces)

Area

U-Value

(sqft)

(BTU/hr/sqft/F)

Unconditioned

Space

Temp.

Cooling

Heating

(deg

F

or

%)

(deg

F

or

%)

Walls

Ceilings

Floors

INFILTRATION

GROUND

ELEMENT

Cooling

CFM/sqft

=

CFM

Area

sqft

Heating

CFM/sqft

:

CFM

Perimeter

Typical

CFM/sqft

=

CFM

Depth

KEYS:

People

Activity

Levels:

1.

Seated

at

Rest

2.

Office Work

3.

Sedentary

Work

4.

Medium Work

5.

Heavy

Work

(230S/120L)

(245S/205L)

(280S/270L)

(295S/455L)

(525S/925L)

Lighting

Fixture Type:

1.

Recessed,

not vented

2.

Vented

(25)

characteristics.

Usually

a zone

is

selected

for

group

of spaces

that

will

be

under

the

same

HVAC

system.

An

example

of a zone

input

sheet

is

on

the

following

page.

2.1.7

Running

the

Program

-The

program can

be

run

for

a

single

hour

calculation or multiple

hour

calculations.

Usually

multiple

hour

calculations are used

to

determine

the

peak

cooling

load

of

the

system.

A

single point

calculation

is

used

to

determine

the

peak

(26)

ZONE INPUT

SHEET

1.

ZONE NAME AND

TYPE

7one Name

2.

THERMOSTAT

AND EQUIPMENT SCHEDULE

COOLING

EQUIPMENT

Joh Name

Zone

Type

= ₁

Normal

Zone

2

Single-Space Zones

Unoccupied

co

Starling

hour,

c

No.

hours

in

oc

HEATING

EQUIP

Heating

thermc

oling

setpoint -

F

r.r.{ipiprlppr

cnpied period

MENT

stat setpoint -

F

3.

COOLING

SYTEM

PARAMETERS

SUPPLY

AIR

Type

of

Input

= ₁

CFM/sqft

2

CFM

3

Temperature

Supply

Air

4.

HEATING

SYSTEM PARAMETERS

HEATING SOURCE

Type

of

heating

sytem = 1

Warm Air

2

Hydronic

(If Warm

Air:)

Supply

Temperature

-

F

(If

Hydronic:)

Water Temperatiire

Drnp

_

F

VENTILATION

AIR

Type

of

Input

= ₁

CFM/sqft

2

CFM

3

%

suddIvair

VENTILATION

AIR

Type

of

Input

=

1

CFM/sqft

2

CFM

3 %

supply

air

4

CFM/person

Ventilation Air

SAFETY

FACTOR

Clq

Safety

Factor

= _%

Ventilation Air

SAFETY FACTOR

Heating Safety

4

CFM/person

Factor = V.

5.

OTHER

SYSTEM PARAMETERS

SUPPLY

FAN

Total

static pressure

Total

efficiency

_

in wg

%

2

(Blow-Thru)

%

of vent air

Fan

configuration

EXHAUST AIR

Direct

exhaustair

flow

rate

= ₁

(Draw-Thru)

RETURN AIR

Is

a return air plenum used

(If

Yes:)

%

of

lighting

load

toplenum

%

of roof

load

toplenum

%

ofwall

load

toplenum

COIL

DATA

Cooling

coil

bypass

factor

?

Y

N

%

6.

SPACE SELECTION

Space Name

Qty

Space Name

Qty

Space Name

Qty

1

18

35

2 19

36

3

20

37

4 21

38

5

22

39

6

23

40

7

24

41

8

25

42

9

26

43

10

27

44

11

28

45

12

29

46

13

30

47

14

31

48

15

32

49

16

33

50

(27)

2.2

Building

Input

2.2.1

Weather

Input

-Weather

data

was

taken

from

the

area of

Hartford

Connecticut.

2.2.2

Schedule

Data

-There

were

two

type

of

schedules,

people and

lighting

&

electric.

The

people

schedule was as

follows:

Week

Day

100%

occup.