QUT lecture The Basics in HVAC 2010

8/7/2019 QUT lecture The Basics in HVAC 2010

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The Basics of

HVAC Systems

Presented by: Rob Lord

QUT

2010


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2010 QUT

Thermal Comfort Defined


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Why are we all different?


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Thermal Comfort Redefined

Pre dic te d Me a n Vo te (PMV)

0

10

20

30

40

50

60

70

80

90

100

-3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3


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Architecture & Heat Balance

2010 QUT


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Psychometric Chart

2010 QUT


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Six elements of comfort

GO TO COMFORT CALCULATOR


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Types of Heat

Sensible Heat measured by

temperature

includes people, lights, computers, sun

Latent Heat measured by wet bulb

temperatureincludes people, boiling kettles, rainy

weather.


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What role for architecture?


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Early Office Days


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Modern Office


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Floor Plate Comparison


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Role of Climate


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Dichotomy of Seasons


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The heart of the matter...


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Our

Weather

BCC

Yellow line

air

conditioning

standard

comfort

envelope

Red Line

comfort

envelope with

the effects ofthermal mass

only...


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Our

Weather

8th October 2008 BCC

Yellow line airconditioning

standard comfort

envelope

Blue Line comfort

envelope with theeffects of thermal

mass only...

Pink line natural

ventilation comfort

envelope

Red Line comfort

envelope with the

effects of night

purge...


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Ventilation+

Thermal

mass

+Night Purge

BCC

Thermal comfort

provided

virtually all year

round


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PMVJan

(hrs)

Feb

(hrs)

Mar

(hrs)

Apr

(hrs)

May

(hrs)

Jun

(hrs)

Jul

(hrs)

Aug

(hrs)

Sep

(hrs)

Oct

(hrs)

Nov

(hrs)

Dec

(hrs)

Year

(hrs) Total (hrs)

< -3.0 0 0 0 0 0 0 0 0 0 0 0 0 0

-3.0 to -2.5 0 0 0 0 0 0 0 0 0 0 0 0 0

-2.5 to -2.0 0 0 0 0 0 1 5 0 0 0 0 0 6

-2.0 to -1.5 0 0 0 0 0 16 15 1 0 0 0 0 32

-1.5 to -1.0 0 0 0 0 1 32 30 44 0 0 1 0 108

-1.0 to -0.5 1 0 0 0 23 47 75 98 9 0 10 0 263 409

-0.5 to 0.0 6 1 1 10 84 79 70 78 84 50 42 5 510

0.0 to 0.5 104 77 140 157 112 35 25 9 100 148 135 102 1144 1654

0.5 to 1.0 69 71 74 41 10 0 0 0 7 32 26 70 400

1.0 to 1.5 27 30 4 2 0 0 0 0 0 0 3 16 82

1.5 to 2.0 13 15 1 0 0 0 0 0 0 0 2 17 48

2.0 to 2.5 7 6 0 0 0 0 0 0 0 0 1 0 14

2.5 to 3.0 3 0 0 0 0 0 0 0 0 0 0 0 3

> 3.0 0 0 0 0 0 0 0 0 0 0 0 0

0 547

Total 230 200 220 210 230 210 220 230 200 230 220 210 2610

Legend Below -0.5

Between -0.5 and 0.5

Above 0.5

16%

63%

21%

Office Hour Profiles & loads

Statistically, 37% of year requires some mechanical augmentation if AC is expected

if people expect NV, then only 12% of the year requires augmentation.


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Thermal Comfort Notes

Justification of Technology

Justification of Technology:-

1. When the comfort guarantee is

expected workspaces2. When reliability of comfort provides

greater patronage retail

3. When value of floor area makes largerfloor plates more cost effective

4. When peoples health is at stake


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Relationships

When you design a new space, you are

creating a relationship between

architecture, people and technology. The

success of the space is often measured by

the success of these relationships.

Relationships need to be intimate, capable

of adjustment over time, not favouring anyone party. Example operable windows.


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Zoning for orientation

In any space with an externalconnection, a perimeterzone exists a space ofbetween 3m & 5m where theheat profile coming throughthe faade is specific to thatorientation.

By dedicating a zone toaccommodate theseorientations, the internalzone is protected.


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Zoning for use


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Refrigeration Cycle


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Room Air Conditioners


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Split Systems


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Split Systems


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Ducted Split Systems


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VRV Systems


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Ducted Packaged Units


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Packaged Refrigeration Cycle


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Water Cooled Packaged


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Chiller Refrigeration Cycle


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Chilled Water Systems


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A history of problems

Carrier creates the psychrometric chart 1900s

Birth of commercial air conditioning 1930s

Growing degree of control through 1950s

Legionaires disease 1967 Energy Crisis 1973

Ozone Depletion 1970s

Sick Building Syndrome 1980s

Global Warming 1990s

Green Building Schemes 2000s


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Energy Use per Capita


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Impact of Energy Consumption


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Evidence of Climate Change


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The Conundrum

How do we balance environment with

convenience?


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Holistic Approach Required


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The Need to Integrate

Architecture has the ability to enhance or hinder

the performance of services

Passive design can work alongside air

conditioning architecture.

Nature & therefore site analysis can provide

opportunities to provide comfort with reduced

need for electrical energy consumption.

Prioritise the energy efforts reduce, reuse,

recycle thermal energy.


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Mixed Mode Air Conditioning


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Mixed Mode Air Conditioning


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Displacement Ventilation


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Under-floor Air Supply

Requires raised floor

Allows user adjustment

Can be quite flexible


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Personalized Air Conditioning


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Natural Ventilation


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Chilled Slabs


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Chilled Beam


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Chilled beam variations


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What is the HVAC system?

Key iss es - er y

11HVAC

Syst

HVAC

Syst

22


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O

Insulation

Sealing &

Double Glazing

Efficient

Equipment

MechanicalCooling &

Ventilation

MechanicalCooling &

Ventilation

Smaller

plant

Low-e glass

coating &

shading

Reduce Loads

Recycled

+ fresh air

mix

Efficient

Lighting

Heat Recovery

Tempered Air

Supply

100%

outside air


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Thermal Comfort & Productivity


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Benefits of Good Air Quality


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Healthy workspaces


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Space, Ventilation & Productivity


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Rewarding the Market Leaders


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Evidence of Climate Change


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HVAC

Options

Option 1

Standard

Variable Air Volume(VAV)

Option 2 Low TemperatureVariable AirVolume(VAV)

Option 3 - Chilled BeamsOption 4 - Under FloorAirDistribution (UFAD)

SCHEME

Benefits

3 Lower capital cost3 Lower capital cost

3 Less ceiling spacerequired

3 Smaller plant area more

NLA3 Low noise levels

3 Low maintenance3 Minimal ceiling space

required3 Improved zoning andthermal comfort

3 100% fresh air - Norecirculation

3 Individual occupant thermalcontrol3 No ceiling space required

3 Reduced floor-to-floorheight

3 100% fresh air - Norecirculation

Issues 2 High maintenance

2 Air is recirculated2 High maintenance2 Air is recirculated

2 Higher capital cost

2 Higher condensation risk

2 Higher capital cost2 Medium maintenance

G +3 credits +3 credits +9 credits +9 credits


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HVAC

Options Option 1

Standard

Variable Air Volume(VAV)

Option 2 Low TemperatureVariable Air Volume(VAV)

Option 3 - Chilled BeamsOption 4 - Under Floor AirDistribution (UFAD)

SCHEME

ABGR

4 to 4 Star ABGR 4 Star ABGR withmargin

5 Star ABGR 4 Star ABGR

Cost

$350 /m $360 /m $410 /m $510 /m

Op$

High High Low Medium


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BCA Energy Efficiency

Fabric Insulation (J1)

Glazing & Shading (J2)

Sealing (J3)

Services Air Movement (J4)

HVAC (J5)

Lighting & Power (J6)

Hot Water (J7)

Maintenance & Access On-going maintenance (I2)

Access for Maintenance (J8)

INTENTI N: -IMPROVING THE LOWER END OF THE MARKET BY 20%

ey ESD issues - Energy

J1J1

J3J3

HVAC

System

J5

HVAC

System

J5J5

J2J2J7J7

J4J4J6J6

J8J8

Documents

QUT lecture The Basics in HVAC 2010