a comparative analysis on the effect of double- skin...

A Comparative Analysis On The Effect Of Double-

Skin Façade Typologies On Overall Building Energy

Consumption Performance In A Temperate Climate

DT175a – Module: ARCH4258 – Final Year Dissertation

Aaron Regazzoli

C09424237

Supervisor: Rory Greenan

10/05/2013

Abstract

Bsc Architectural Technology i

Abstract

One of the most important factors affecting the energy performance within a building

is a carefully and efficiently designed façade. The primary aim of this research was

to present a critical examination of the effect on the energy consumption of an office

building located within a temperate climate utilising Double-Skin Façade construction

as opposed to a conventional single-skin curtain wall system.

A comparative analysis of the effect on the overall energy consumption within an

office building was investigated in which a combination of various Double-Skin

Façade configurations, systems and cavity depths were utilised.

The use of computer aided dynamic thermal modelling was incorporated in order to

ensure the calculation of accurate and efficient simulations of the various Double-

Skin Façade systems due to the complex nature of the various functions within the

façade cavity.

Through the use of the dynamic thermal modelling simulations, a detailed analysis of

the efficiency of each respective combination of Double-Skin Façade construction

simulated was comprised. As such the optimum façade combination for use within

an office building located in a temperate climate was identified.

Acknowledgements

Bsc Architectural Technology ii

Acknowledgements

I would like to express my sincere thanks and appreciation to all staff of Dublin

Institute of Technology throughout my time within the college.

In particular to my current year head Sima Rouholamin for always finding the time

when I was in need of any assistance or guidance.

My assistant year head David Palmer, this dissertation wouldn’t have been possible

without his continuous guidance and direction. I truly appreciate his interest and

association with this research.

My research supervisor Rory Greenan, who provided me with valuable knowledge

and input throughout the course of the dissertation. In particular for getting me

started with the complex simulations and patiently replying to any queries which I

had.

Finally, I am indebted to my family, girlfriend and friends for encouraging me to

pursue this degree and research, without their support and encouragement

throughout my time within the course this would not have been possible.

Aaron Regazzoli,

May 2013.

Declaration

Bsc Architectural Technology iii

Declaration

I hereby declare that the work described within this dissertation is, except where

otherwise stated, entirely my own work and has not been submitted as an exercise

for a degree at this or any other university.

___________________

Aaron Regazzoli,

10/05/2013.

Contents

Bsc Architectural Technology iv

Table of Contents

Abstract ....................................................................................................................... i

Acknowledgements ..................................................................................................... ii

Declaration ................................................................................................................. iii

1.0 Introduction .......................................................................................................... 1

1.2 Double-Skin Façade Concept ........................................................................... 2

1.3 Research Objectives ......................................................................................... 4

2.0 Double Skin Façade Configuration ....................................................................... 6

2.1 Double-Skin Façade Construction .................................................................... 6

2.2 Double-Skin Façade Configuration ................................................................... 7

2.2.3 Box Façade ................................................................................................ 8

2.2.4 Corridor Façade ......................................................................................... 9

2.2.5 Shaft-Box Façade .................................................................................... 10

2.2.6 Multi-Storey Façade ................................................................................. 11

2.3 Double-Skin Façade System .......................................................................... 12

2.3.1 Naturally Ventilated Cavity ....................................................................... 12

2.3.2 Sealed Cavity ........................................................................................... 12

2.3.3 Regulating Cavity (Mixed-Mode Ventilation) ............................................ 13

3.0 The Role of Double-Skin Façades – Energy Consumption ................................ 14

3.1 Energy Performance - Double-Skin Façade ................................................... 15

3.2 Thermal Buoyancy (Stack Effect) ................................................................... 16

4.0 Dynamic Thermal Modelling - Methodology ....................................................... 18

4.1 Research Context ........................................................................................... 18

4.2 Establishing Base Model Parameters ............................................................. 19

4.2.1 Hawkins House Redevelopment – ‘’Drum’’ Office Area .......................... 19

4.2.2 Conventional Single-Skin Façade – Base Model Analysis ....................... 22

4.2.3 Double-Skin Façade Configurations ......................................................... 23

Contents

Bsc Architectural Technology v

4.3 Analysis / Simulations ..................................................................................... 24

4.3.1 SunCast ................................................................................................... 24

4.3.3 Vista Results Analysis .............................................................................. 25

4.3.4 MacroFlo .................................................................................................. 26

5.0 Dynamic Thermal Modelling Simulations ........................................................... 27

5.1 Analysis of Simulation Results ........................................................................ 27

5.1.1 Annual Energy Consumption (mWh) ........................................................ 27

5.1.2 Annual Heating and Cooling Loads (kWh) ............................................... 28

5.1.3 Annual Energy Consumption (kWh/m²) .................................................... 30

6.0 Conclusions and Recommendations .................................................................. 34

6.1 Comparison of Façade Configuration Energy Consumption ........................... 34

6.2 Recommendations – Optimum Cavity Depth .................................................. 37

6.3 Areas for Further Research ............................................................................ 38

References ............................................................................................................... 39

Appendix 1: The History of Double-Skin Façades ...................................................... 1

Appendix 2: IES Virtual Environment User Interface .................................................. 1

Appendix 3: Double-Skin Façade – Energy Consumption and Cost Analysis ............ 1

Table of Figures

Bsc Architectural Technology vi

Table of Figures

Chapter 1

Figure 1.1: Impact of the building façade on energy consumption (King, 2010). ........ 2

Figure 1.2: Typical Double-Skin Façade Configuration (ArchiExpo, 2003) . ............... 3

Chapter 2

Figure 2. 1: Typical Double-Skin Façade Composition (Caine, 2013). ....................... 6

Figure 2. 2: Corridor Façade Google SketchUp Model............................................... 7

Figure 2. 3: Box Façade Google SketchUp Model ..................................................... 7

Figure 2. 4: Multi-Storey Façade Google SketchUp Model ........................................ 7

Figure 2. 5: Shaft-Box Façade Google SketchUp Model ............................................ 7

Figure 2. 6: Box Façade Elevation ............................................................................. 8

Figure 2. 7: Box Façade Section ................................................................................ 8

Figure 2. 8: Box Façade Plan ..................................................................................... 8

Figure 2. 9: Site Assembley of Prefabricated Box Façade Elements (Oesterle, et al.,

2001). ......................................................................................................................... 8

Figure 2. 10: Corridor Façade Section ....................................................................... 9

Figure 2. 11: Corridor Façade Elevation ..................................................................... 9

Figure 2. 12: Corridor Façade Plan ............................................................................ 9

Figure 2. 13: Corridor Façade (Oesterle, Lieb, Lutz, & Heusler, 2001). ..................... 9

Figure 2. 14: Shaft-Box Façade Elevation ................................................................ 10

Figure 2. 15: Shaft-Box Façade Section ................................................................... 10

Figure 2. 16: Shaft-Box Façade Plan ....................................................................... 10

Figure 2. 17: ARAG 2000 Building Shaft-Box Façade (Oesterle, et al., 2001). ........ 10

Figure 2. 18: Multi-Storey Façade Plan .................................................................... 11

Figure 2. 19: Multi-Storey Façade Elevation ............................................................ 11

Figure 2. 20: Multi-Storey Façade Section ............................................................... 11

Figure 2. 21: Multi-Storey Façade (Gonchar, 2013). ................................................ 11

Figure 2. 22: Classification of Double-Skin Façades and Ventilation Methods. ........ 12

Figure 2. 23: Sketch Indicating airflow induced due to the stack effect. ................... 12

Figure 2. 24: Motorised Façade Ventilation Opening (BBRI, 2004). ......................... 13

Table of Figures

Bsc Architectural Technology vii

Chapter 3

Figure 3. 1: Schematic diagram heat transfer through a Double-Skin Façade. ........ 15

Figure 3. 2: Double-Skin Façade Winter and Summer Operations (Gonchar, 2013).

................................................................................................................................. 17

Chapter 4

Figure 4. 1: Proposed Redevelopment of Hawkins House South-Façade................ 18

Figure 4. 2: Hawkins House Redevelopment which highlights the proposed office

area. ......................................................................................................................... 19

Figure 4. 3: IES Applications User Interface. ............................................................ 20

Figure 4. 4: IES Room Function Interface. The office area (in green) and additional

Hawkins House redevelopment (pink) is highlighted above. .................................... 21

Figure 4. 5: IES Room Template Interface. .............................................................. 21

Figure 4. 6: Hawkins House Redevelopment 3D IES Virtual Environment Model. ... 22

Figure 4. 7: Hawkins House Redevelopment IES 3D Base Model. .......................... 22

Figure 4. 8: Corridor Façade .................................................................................... 23

Figure 4. 9: Multi-Storey Façade .............................................................................. 23

Figure 4. 10: Shaft-Box Façade ............................................................................... 23

Figure 4. 11: Box Façade ......................................................................................... 23

Figure 4. 12: IES SunCast – Solar Shading Calculations. ........................................ 24

Figure 4. 13: ApacheSim Parameters User Interface. .............................................. 25

Figure 4. 14: Vista Results Analysis Interface. ......................................................... 25

Figure 4. 15: MacroFlo Openings Database Manager Interface. .............................. 26

Chapter 5

Figure 5. 1: Annual Energy Consumption – Dynamic Thermal Modelling Simulations.

................................................................................................................................. 27

Figure 5. 2: Annual Heating and Cooling Loads - 200mm Cavity Depth. ................. 28

Figure 5. 3: Annual Heating and Cooling Loads - 600mm Cavity Depth. ................. 29

Figure 5. 4: Annual Heating and Cooling Loads - 1000mm Cavity Depth. ............... 29

Figure 5. 5: Box Façade – Annual Energy Consumption (kWh/m²). ......................... 31

Figure 5. 6: Corridor Façade – Annual Energy Consumption (kWh/m²). .................. 31

Figure 5. 7: Shaft-Box Façade – Annual Energy Consumption (kWh/m²). ............... 32

Figure 5. 8: Multi-Storey Façade – Annual Energy Consumption (kWh/m²). ............ 32

Figure 5. 9: Shaft-Box Façade Configuration – Airflow Concept. ............................. 33

Table of Figures

Bsc Architectural Technology

viii

Chapter 6

Figure 6. 1: Annual Energy Consumption – Facade Efficiency Comparison. ........... 34

Figure 6. 2: Multi-Storey Façade Regulating Cavity – Determination of Optimal

Cavity Depth. ............................................................................................................ 35

Figure 6. 3: Annual Energy Consumption Cost – Optimal Cavity Depth. .................. 36

Figure 6. 4: Horizontal Pivoting Transparent Slats (Teuxido, 2013). ........................ 38

Appendix 1

Appendix 1. 1: Steiff Factory Giengen, Germany. Circa 1904 (Solla, 2013). .............. 1

Appendix 1. 2: Famhouse Box-Type Windows in Mürren, Switzerland (Oesterle, et

al., 2001). ................................................................................................................... 1

Appendix 1. 3: Narkomfin Housing Building, Moscow, Russia. Circa 1928 (Wolfe,

2013). ......................................................................................................................... 2

Appendix 1. 4: Corbusier Sketch Illustrating Ideas (Tascón & Hernandez., 2008). .... 2

Appendix 2

Appendix 2. 1: Office Room Conditions. ..................................................................... 1

Appendix 2. 2: Double-Skin Façade Room Conditions. .............................................. 1

Appendix 2. 3: Double-Skin Façade MacroFlo Opening Template – Sealed Cavity. .. 2

Appendix 2. 4: Double-Skin Façade MacroFlo Opening Template – Naturally

ventilated Cavity. ........................................................................................................ 2

Appendix 2. 5: Double-Skin Façade MacroFlo Opening Template – Regulating

Cavity. ........................................................................................................................ 3

Appendix 3

Appendix 3. 1: Annual Energy Consumption Overview (mWh). ................................. 1

Table of Tables

Bsc Architectural Technology ix

Table of Tables

Chapter 1

Table 1.1: Reasearch Objectives Mapped to Methods...............................................5

Appendix 3

Appendix Table 3.1: Base Model Experimental Parameters.....................................1

Appendix Table 3.2: Base Model Examination..........................................................1

Appendix Table 3.3: IES Test Results.......................................................................2







Appendix Table 3.10: IES Test Results.....................................................................4



Appendix Table 3.13: IES Test Results ....................................................................5


Chapter 1 Introduction

BSc Architectural Technology 1

1.0 Introduction

The primary aim of this research is to present a critical examination of the energy

performance associated with the use of various Double-Skin Façade typologies and

systems in an office building located within a temperate climate.

The concept of Double-Skin Façade construction is not a recent methodology and

dates back to the middle of the 19th century. However, rapid development of the

concept began during the 1970’s as a result of the oil crisis’ of 1973 and 1979

(Dickson, 2003). A growing concern regarding energy consumption during this period

resulted in an acceleration in improvements within the glass industry, and in turn

Double-Skin Façade technology also seen significant advancements (Bayram,

2003). A detailed account of the history of Double-Skin Façades can be seen in

Appendix 1.

Currently within the construction industry, buildings are not merely a simple

combination of stone and glass. In fact according to (Bayram, 2003) they are

becoming increasingly more energy efficient and as a result are achieving high

performance standards due to constant technological advancements and ever

increasing performance requirements.

The building façade acts as a ‘’filter’’ between the internal and external

environments. As a result It provides protection to the building interior from

undesirable impacts such as excessive heat gain, cold, radiation and wind generated

from the external environment (Consultants, 2013). As a result the façade is the

primary moderator between the external and internal environments, which underlines

the importance of the façade as a key aspect of reducing overall energy

consumption (Palmer, 2011). According to (King, 2010) 8% of energy consumption

within office buildings is as an direct result of heat loss through the façade walls and

windows; however the façade can have an indirect effect on a further 56% of energy

consumed through related functions such as infiltration, HVAC – heating, cooling and

air-conditioning and lighting (Palmer, 2011), see figure 1.1 below for a diagrammatic

representation of the effects in which the building façade impacts on overall energy

consumption.



The possibility of Double-Skin Façade construction providing a reduction in energy

consumption related to heating and cooling loads in an office building is studied to

determine whether it is an energy efficient method of façade construction. In addition

a brief cost analysis will be outlined to evaluate if reduced energy consumption

justifies the initial construction costs in a long-term assessment. Previous cost

analysis show that the initial cost of Double-Skin Façade construction can range

from 200%-300% of conventional single-skin façade construction, depending on the

façade composition (Bayram, 2003).

1.2 Double-Skin Façade Concept

The term Double-Skin Façade can be defined as a combination of a traditional

single-skin façade which is doubled on the outside by a second layer, essentially an

additional glazed façade. Each of these layers are commonly referred to as a skin,

hence the origin of the widely used term ‘’Double-Skin Façade’’. In addition, a

naturally ventilated, sealed or self-regulating cavity is located between each skin

having a width which can range from several centimetres at the narrowest to several

metres for the widest accessible cavities (BBRI, 2004).

Figure 1. 1: Impact of the building façade on energy consumption (King, 2010).



The glazing may stretch over an entire structure or over just a portion of it. The

internal layer of glass, typically insulating, serves as part of a conventional structural

wall or a curtain wall, while the additional layer, usually single glazed, is placed in

front of the main glazing and as a result creates the air space (Uuttu, 2001). An

example of typical Double-Skin Facade configuration is shown below in figure 1.2:

According to (Arons, 2000) the main objectives of the Double-Skin Façade concept

can be briefly defined under the following headings:

1. Reduced Energy Consumption and Ecological Responsibility

2. Natural Ventilation

3. Cost Reduction

4. Acoustic Insulation

5. Occupant Comfort

6. Increased Occupant Productivity

7. Additional Building Security

External Layer

Ventilation Grille

Internal Layer

Spandrel Panel

Grated Walkway

Figure 1. 2: Typical Double-Skin Façade Configuration (ArchiExpo, 2003) .



1.3 Research Objectives

The Aim of this research is to provide a critical evaluation as to whether Double-Skin

Façade construction plays an important role in reducing energy consumption within

office buildings in a temperate climate.

The objectives of this research are as follows:

1. To characterise the various methods of Double-Skin Façade configuration and

construction used within the construction industry.

2. To research and establish the advantages and disadvantages associated with

the respective systems of Double-Skin Façade construction.

3. To determine the role and effect of Double-Skin Façade construction on

energy consumption and performance of buildings.

4. To carry out a comparative analysis of the effect on energy consumption on

buildings through various Double-Skin Façade configurations and systems as

opposed to conventional curtain wall construction.

5. To determine the performance efficiency against conventional curtain wall

construction and the associated payback durations of each respective system

in relation to the information obtained through research.

6. To establish the optimal combination of Double-Skin Facade configuration,

system and cavity depth in relation to overall building energy consumption for

use within an office building located in a temperate climate.

Objectives mapped to Research Methods:

Objectives Research Methods

Characterise the various methods of

Double-Skin Façade configurations.

Review current literature on methods of

classification of Double-Skin Façade typologies.

To research and establish the

advantages and disadvantages

associated with the respective systems

of Double-Skin Façade construction.

Review current literature on the advantages and

disadvantages that are associated which each

respective system of Double-Skin Façade

configuration with the construction industry.

To determine the role and effect of

Double-Skin Façade construction on

energy consumption and performance of

buildings.

Review available data and literature on the role

and effect that Double-Skin Façade construction

plays on the consumption of energy within

buildings.



To carry out a comparative analysis of

the effect on energy consumption on

buildings through various Double-Skin

Façade configurations and systems as

opposed to conventional single-skin

curtain wall construction.

To perform computer aided dynamic thermal

modelling on various scenarios to determine the

respective energy consumption of various

Double-Skin Façade configurations.

To determine the performance efficiency

against conventional curtain wall

construction and the associated payback

durations of each respective system in

relation to the information obtained

through research.

Prepare a comparison of results from thermal

dynamic modelling to determine respective

system efficiency. Review of current data on

estimated Double-Skin Façade construction

costs and provide detailed outputs of payback

periods of each respective system tested.

To establish the optimal combination of

Double-Skin Façade configuration,

system and cavity depth in relation to

overall building energy consumption for

use within an office building located in a

temperate climate.

Through the comparison and analysis of the

results obtained through the use of the dynamic

thermal modelling simulations, to identify and

determine the most efficient combination of the

various double-skin façade parameters

evaluated.

Table 1.1: Reasearch Objectives Mapped to Methods.

In Conclusion, through a detailed investigation into the various methods of Double-

Skin Façade construction and configuration, the knowledge required in order to

effectively and efficiently determine the parameters of the dynamic thermal modelling

simulations are to be identified.

Chapter 2 Double-Skin Façade Configuration


2.0 Double Skin Façade Configuration

In this chapter the typical composition of a Double-Skin Façade is examined in

further detail, together with an explanation of the various methods of classification

used within the construction industry to define the Double-Skin Façade configuration.

2.1 Double-Skin Façade Construction

There are a wide range of definitions from a large range of authors as to what

components actually constitute a Double-Skin Façade. However, the layers of a

Double-Skin Façade are generally comprised of the following elements:

External Glazing: The exterior layer

usually comprises of heat strengthened

safety or laminated safety glass. It may

be airtight or open with air inlet and

outlet openings controlled by either

manual or automated opening vents.

This layer may be completely glazed

and is used as a rain screen to provide

protection to the interior layer from the

external climatic conditions (Lee,

Selkowitz, Bazjanac, Inkarojrit, & Kohler,

2002).

Internal Glazing: The interior layer is

usually comprised of a fixed or operable

thermal insulating double or triple pane

glazed unit. Clear, low emmitance

coating, solar diffusion glazing, etc. can

be used on the internal glazing in order

to reduce the radiative heat gains to the

interior. This layer is generally

comprised of some built or opaque

elements and may contain fixed or operable casement or hopper windows,

depending on the ventilation strategy used (Lee, et al., 2002).

Figure 2. 1: Typical Double-Skin Façade Composition

(Caine, 2013).



Intermediate Cavity: The intermediate cavity between the external and internal

layers can be naturally, regulating (mixed-mode ventilation) or completely sealed.

The width of the cavity can vary as a function of the applied concept and can range

from 200mm to over 2m. The width of the intermediate cavity determines the

physical properties of the façade and the way in which it is maintained (Streicher et

al., 2007).

Any adjustable sun shading or day lighting equipment enhancement devices are

generally installed within the intermediate cavity to protect the internal rooms from

external elements and as a less expensive method than the use of externally

mounted systems. The airflow throughout the intermediate space is determined by

solar induced thermal buoyancy and through the effects of the wind (Oesterle, et al.,

2001).

2.2 Double-Skin Façade Configuration

There are many methods of configuration and classification of Double-Skin Façades.

Each one is dependent on design principles such as the origin and direction of air

flow within the cavity, the façade configuration and also according to the form in

which the intermediate space is divided. However, the principle factor which

determines the Double-Skin Façades classification is according to the desired

ventilation function (Oesterle, et al., 2001).

There are four main categories of configuration of Double-Skin Façades, as

mentioned below:

1. Box Façade: (Figure 2.2)

2. Corridor Façade (Figure 2.3)

3. Shaft-Box Façade (Figure 2.4)

4. Multi-Storey Façade (Figure 2.5)

Figure 2. 2: Box Façade

Google SketchUp Model

Figure 2. 3: Corridor

Façade Google SketchUp Model

Figure 2. 4: Shaft-Box


Figure 2. 5: Multi-Storey




2.2.3 Box Façade

According to (Oesterle, et al., 2001) the Box Façade is one of the oldest forms of

Double-Skin Façade configuration.

It is comprised of modular single storey Double-Skin Façade box units which are

divided by structural bay widths or on a room-by-room basis (Lee, et al., 2002).

The exterior single glazed skin contains openings in order to allow the ingress of

fresh air and the egress of stale air. Resulting in the ability of both the intermediate

space and internal rooms to be naturally ventilated (Oesterle, et al., 2001).

Box Façade configuration is most commonly used in situations where consideration

is given due to high external noise levels and when there are special requirements

regarding the transmittance of sound between adjoining rooms (Oesterle, et al.,

2001).

According to (Uuttu, 2001) the main advantages of a Box Façade configuration are:

1. Improvement of sound insulation both

horizontally and vertically across the façade

cavity.

2. Division into fire protection levels is achievable

throughout the façade cavity.

3. Occupant Controlled natural window ventilation

can be achieved.

Figure 2. 2: Box Façade Elevation Figure 2. 3: Box Façade Section Figure 2. 4: Box Façade Plan

Figure 2. 5: Site Assembley of

Prefabricated Box Façade Elements (Oesterle, et al., 2001).



2.2.4 Corridor Façade

A Corridor Façade is a single-storey façade which is separated horizontally at each

intermediate floor area (Uuttu, 2001).

It does not contain any vertical divisions except those that are required at the corner

of the building or elsewhere due to structural, acoustic or fire protection reasons

(Lee, et al., 2002).

The exterior single glazed skin contains openings that are usually positioned in a

staggered format from bay to bay in order to prevent stale air extracted on one floor

entering the cavity space of the floor immediately above (Oesterle, et al., 2001).

A Corridor Façade configuration is typically used in the situation of high-rise

buildings (Oesterle, et al., 2001).

According to (Uuttu, 2001) the main advantages of a Corridor Façade configuration

are:

1. Improvement of sound insulation both horizontally and

vertically across the façade cavity.

2. Division into fire protection levels is achievable

throughout the façade cavity.

3. Occupant Controlled natural window ventilation can be

achieved.

Figure 2. 7: Corridor Façade Elevation Figure 2. 6: Corridor Façade Section Figure 2. 8: Corridor Façade Plan

Figure 2. 9: Corridor Façade

(Oesterle, Lieb, Lutz, & Heusler, 2001).



2.2.5 Shaft-Box Façade

The Shaft-Box Façade is a unique variation of a Box Façade configuration with a

combination of both a Double-Skin Façade with a Multi-Storey Cavity and one with a

single-storey cavity (Uuttu, 2001).

It is comprised of an alternating layout of box façade units and vertical shaft

elements that are linked through airflow openings (Oesterle, et al., 2001).

As a result the vertical height of the shaft creates strong uplift forces due to the

increased stack effect and draws the air from the box façade elements up to the top

of the shaft where it is exhausted (Lee, et al., 2002).

Shaft-Box Façade configuration is typically used in low-rise buildings (Oesterle, et

al., 2001).

According to (Uuttu, 2001) the main advantages of a Shaft-Box Façade configuration

are:

1. Improvement of sound insulation both

horizontally and vertically across the

façade cavity.

2. Occupant Controlled natural window

ventilation can be achieved.

3. Provides additional building security.

Shaft Element

Figure 2. 11: Shaft-Box Façade Section Figure 2. 10: Shaft-Box Façade Elevation Figure 2. 12: Shaft-Box Façade Plan

Figure 2. 13: ARAG 2000 Building Shaft-Box

Façade (Oesterle, et al., 2001).



2.2.6 Multi-Storey Façade

In a Multi-Storey Façade the cavity is not separated horizontally or vertically by

divisions, it extends over the whole extent of the building envelope (Oesterle, et al.,

2001).

The principle behind a Multi-Storey Façade is dependent on air that accumulates at

the top of the cavity will heat up on a warm day and as a result will be exhausted

from the openings in the roof or external skin and in turn will result in cooler air being

drawn in from the base of the façade and replacing the exhausted air (Uuttu, 2001).

A Multi-Storey Façade configuration is most suited where external noise levels are

high and acoustic insulation is a key design requirement (Oesterle, et al., 2001).

According to (Uuttu, 2001) the main advantages of a Multi-Storey Façade

configuration are as follows:

1. Improvement of sound insulation both horizontally

and vertically across the façade cavity.

2. Occupant Controlled natural window ventilation

can be achieved.

3. Provides additional building security.

4. Shading devices placed within the cavity are

protected from the climatic elements as opposed

to externally mounted systems

Figure 2. 15: Multi-Storey Façade Elevation Figure 2. 16: Multi-Storey Façade Section

Figure 2. 14: Multi-Storey Façade Plan

Figure 2. 17: Multi-Storey Façade (Gonchar, 2013).



2.3 Double-Skin Façade System

In addition there are numerous combinations and design possibilities by varying the

partition configuration, ventilation system and airflow method (Aksamija).

2.3.1 Naturally Ventilated Cavity

The British Standard BS EN (12792., 2003) defines the process of natural ventilation

as dependent on pressure differentiation without the aid of air movement

components. The two driving forces that determine the effectiveness of natural

ventilation in Double-Skin Façades are the differences in pressure within the cavity

generated by thermal buoyancy, or the stack effect, and also by the effect of wind

velocity (BBRI, 2004).

The principle of the stack effect is dependent on

the theory that the warm air inside the cavity is less

dense than the cooler external air, and as a result

will be drawn out from openings located at the top

of the building envelope; as a result cooler denser

air will enter openings lower down. The process

will continue if the air entering the building is

continuously heated, typically by casual or solar

gains (Baker, 2013). The principle of the stack

effect is shown in figure 2.23 to the right.

2.3.2 Sealed Cavity

According to (Permasteelisa, 2013) a sealed cavity, or closed cavity façade, refers to

the method in a Double-Skin Façade construction whereby the cavities between the

internal and external layers are completely sealed. The concept of a Closed Cavity

Façade is simple and provides a number of benefits according to (Permasteelisa,

2013) such as:

Sealed Regulating

Cavity Airflow

Solar Radiation

Figure 2. 18: Classification of Double-Skin Façades and Ventilation Methods.

Figure 2. 19: Sketch Indicating airflow induced due to the stack effect.



A sealed Double-Skin Façade improves glazing transparency.

Greater energy and cost efficiency compared to naturally ventilated methods.

A sealed façade cavity is an energy saving method of façade construction.

2.3.3 Regulating Cavity (Mixed-Mode Ventilation)

As opposed to either solely naturally ventilated or sealed cavities, it is possible for

several ventilation methods to be utilised simultaneously within a Double-Skin

Façade configuration. In certain cases, the ventilation method can be regulated and

determined by motorised ventilation openings which react with environmental

parameters, such as cavity air temperature, etc. (BBRI, 2004).

Motorised ventilation openings, as presented

in figure 2.24, enable the possibility to vary

from one method of ventilation to another as a

function of their position (BBRI, 2004).

According to CIBSE Guide A (2005)

guidelines such as when the cavity air

temperature exceeds a mean temperature of

28° the motorised ventilation openings will be

activated in order to allow the dissipation of

heat from the façade cavity and as a result

prevent overheating within the façade cavity.

In conclusion, the various Double-Skin Façade configurations and systems

mentioned above, in addition with the variation of the cavity depth, are to be

examined to determine the overall effect on building energy consumption. The role in

which Double-Skin Façade construction affects building energy consumption is

explored within the next chapter in order to determine the main energy saving

principles associated with the use of the Double-Skin Façade concept.

Figure 2. 20: Motorised Façade Ventilation Opening (BBRI, 2004).

Chapter 3 The Role of Double-Skin Façades - Energy Consumption


3.0 The Role of Double-Skin Façades – Energy Consumption

In this chapter the effect on façade performance in the context of Double-Skin

Façade construction is presented, together with an explanation of the various

performative concepts associated.

As briefly mentioned in Chapter 1, the use of Double-Skin Façade construction

provides various performance enhancing benefits to the building envelope.

According to (Arons, 2000) these benefits can be defined under the following

headings:

1. Reduced Energy Consumption and Ecological Responsibility: Reduced

energy consumption is achieved by minimising solar gain through the façade

and reducing cooling loads.

2. Cost Reduction: Double-Skin Façades are significantly more expensive to

construct than a conventional single-skin façade, however according to

(Saelens, 2002) their use reduces long-term costs due to reduced energy

consumption.

3. Natural Ventilation: Due to the protection of the external skin, natural

ventilation through the cavity can be achieved whilst not compromising

occupant comfort during harsh climatic conditions such as wind, rain and

snow.

4. Acoustic Insulation: Due to the addition of an external skin, it is possible to

achieve the same degree of acoustic insulation with the windows open as you

can with the windows closed in conventional single-skin façade construction.

5. Occupant Comfort/Productivity: As occupants are able to control light

penetration with louvers or shading devices and to regulate air movement and

temperature with operable windows the overall building comfort levels are

increased. In turn due to increased environmental control and comfort levels,

work productivity is increased.

6. Additional Security: Double-Skin Façades provide a relatively unobtrusive

method of achieving building security due to a continuous glazing layer with

small ventilation grilles as opposed to project openings with bars or vents.



3.1 Energy Performance - Double-Skin Façade

Energy consumption in relation to Double-Skin Façades for heating and cooling

loads is directly related with the total glazing area as the majority of the heat gains

and losses occur through the glass surfaces (Bayram, 2003).

Various standard values defining thermal transmission are used in building physics.

The coefficient of thermal transmission (U-Value) is the standard that is used to

describe the transfer of heat through a construction element in terms of the ambient

temperature differential on both sides of the construction element. The unit of

measurement of the U-Value is W / m² K (Oesterle, et al., 2001).

Although due to the nature of Double-Skin Façade construction the calculation of

heat transfer is a complex process as there are a wide range of methods of heat

transfer occurring simultaneously. These methods of heat transfer include laminar

and turbulent flows, temperature differentiation, density stratifications and varying

air-velocities (Tascón & Hernandez., 2008).

As a result the use of standard U-Value calculations for determining the thermal

performance of Double-Skin Façade construction is not a particularly suitable

method as in reality steady state calculations are not truly representative of the

complex scenarios which occur within a Double-Skin Façade cavity. See figure 3.1

below for a schematic diagram of heat transfer through a Double-Skin Façade.

Figure 3. 1: Schematic diagram heat transfer through a Double-Skin Façade.



However, according to (Bayram, 2003) the factor which has the greatest influence on

energy consumption in the context Double-Skin Façade is the stack effect, or

thermal buoyancy.

3.2 Thermal Buoyancy (Stack Effect)

Thermal Buoyancy is defined as the process which occurs when the density of the

air between the exterior and interior layers of a Double-Skin Façade is increased due

to the heat generated from the greenhouse effect. As the density of the air increases

inside the intermediate space pressure and temperature differences develop along

the height of the façade (Tascón & Hernandez., 2008). As a result of these pressure

differences will be drawn out from openings located at the top of the building

envelope; as a result cooler denser air will enter openings lower down. The process

will continue if the air entering the building is continuously heated, typically by casual

or solar gains (Baker, 2013).

According to (Arons, 2000) there are two main operations which take place in

Double-Skin Façades, summer and winter operations. Each system is

advantageously utilised to reduce energy consumption during the respective hot and

cold seasons.

1. Summer Operations: The air in the cavity removes excess heat by means of

the stack effect in order to prevent excessive heat accumulation in the cavity.

If an accumulation of heat is formed in the cavity unwanted heat passes into

the internal spaces. Therefore, the temperature of the inner skin is kept lower

and conduction, convection and radiation from the internal skin to the

occupied space is reduced. Accordingly less heat is transferred from the

outside to the inside, and less energy is required to cool the space.

2. Winter Operations: In winter the Double-Skin Façade utilises a sealed cavity,

with no air circulation. As the cavity heats up it increases the temperature of

the internal skin, and as a result reduces the conductive, convective and

radiant losses. Accordingly less heat is transferred from the inside to the

outside, and less energy is required to heat the space.

See figure 3.2 below for a diagramatic explanation of the variations in Double-Skin

Façade summer and winter operations.



The configuration of the system used is directly related with the climate in which the

building is located. Some studies show that the heating demand of the Double-Skin

Façades is higher than single-skin conventional façades. On the other hand, its

concept as a thermal buffer utilising the stack effect to remove excessive heat in

summer decreases the cooling loads significantly. Furthermore previous studies

show that as compared to the conventional single-skin façade systems Double-Skin

Façades are credited with a 30% reduction in energy consumption (Bayram, 2003).

In the remaining chapters the author intends to provide a critical examination of

energy consumption associated with each respective Double-Skin Façade system.

Each system will be examined through a number of varying parameters to determine

the effectiveness, or inefficiency, of the specific system in question.

Figure 3. 2: Double-Skin Façade Winter and Summer Operations (Gonchar, 2013).

Chapter 4 Dynamic Thermal Modelling - Methodology


4.0 Dynamic Thermal Modelling - Methodology

In this chapter the methodology used to perform a parametric analysis on Double-

Skin Façade energy performance is presented, together with a brief overview of the

parameters chosen as a basis for the computer aided dynamic thermal modelling

simulations.

4.1 Research Context

As the primary aim of this research is to present a critical examination of energy

performance of Double-Skin Façades in office buildings in a temperate climate, the

building selected to be used as a base model for the dynamic thermal modelling

calculations was the proposed design of the Redevelopment of The Hawkins House

Offices on Hawkins Street, Dublin 2. The area of the building selected for detailed

analysis is the proposed ‘’Drum’’ located on the south façade, as shown in Figure 4.1

below:

Due to the nature of Double-Skin Façade construction, computer modelling has been

extensively used to predict energy consumption. For the purpose of the computer

aided dynamic thermal modelling, IES Virtual Environment (VE) software is used for

the building simulation analysis on the various façade configurations, systems and

depths examined on the proposed ‘’Drum’’ of Hawkins House.

Proposed ‘’Drum’’

Figure 4. 1: Proposed Redevelopment of Hawkins House South-Façade.



4.2 Establishing Base Model Parameters

In order to provide an accurate and extensive critical analysis of Double-Skin Façade

energy consumption, a wide range of variations and permutations are to be

examined. As a result the effectiveness and efficiency of each respective system will

be clearly identifiable and comparable under numerous conditions. In addition to the

comparison of each Double-Skin façade system, an initial analysis using a

conventional single-skin façade will be carried out in order to provide a comparable

base energy consumption value. In order to achieve maximum comparability and

relevance the conventional single-skin façade will be of the same wall construction

as each respective Double-Skin Façade systems internal skin. A brief diagram of the

variations of Double-Skin Façade for examination within the software is shown

below:

Box Façade Corridor Façade Shaft-Box Façade Multi-Storey Façade

Naturally Ventilated Cavity Sealed Cavity Regulating Cavity

200mm 600mm 1000mm

4.2.1 Hawkins House Redevelopment – ‘’Drum’’ Office Area

As highlighted in figure 4.2 to the right, the

proposed office area located on the south

façade of the Hawkins House

Redevelopment will provide the basis for

the computer aided dynamic thermal

analysis on the energy performance on

Double-Skin Facades. The proposed office

area is comprised of a total of five floors,

with a total combined floor area of

852.44m².

Due to the complexity of the IES Virtual Environment software one limitation of the

research resulted in the computer aided thermal model using a rectangular floor plan

Figure 4. 2: Hawkins House Redevelopment which highlights the proposed office area.



in the proposed office area as opposed to the elliptical ‘’drum’’ shape as shown

above. In order to achieve a representative as possible model, the rectangular office

floor plan is comprised of the key dimensions of the major and minor axis of the

elliptical drum shape (14.8m & 11.2m respectively).

IES Virtual Environment is divided into a number of

applications which each have specific performative or

informative functions in a wide range of areas relating to

thermal performance, design, solar shading etc. For the

purpose of a dynamic thermal modelling analysis of the

Hawkins House Redevelopment the Virtual Environment

Applications which must be utilised are as follows:

Model IT

SunCast

Apache Thermal

Vista Results

Macroflo

Microflo – CFD

The first step involved in the utilisation of the IES Virtual Environment software is to

create a 3D model of the desired building area, ie. The ‘’Drum’’. This 3D model

provides the basic information required for the additional IES applications to run

simulations and calculations.

The IES application in which you create and edit buildings and components is Model

IT. Even though the thermal analysis is specifically focused on the ‘’Drum’’ office

area, in order to create an accurate model it is necessary that the entire Hawkins

House Redevelopment is digitally modelled. This is to ensure the integrity of the

dynamic thermal calculations as the effects the surrounding building has on the

office area will be considered and evaluated, i.e. shading from the sun and the effect

of the wind. In order to the Hawkins House redevelopment in its entirety, two main

modelling functions must be used, ‘’Room’’ and ‘’Adjacent Building’’. These functions

define which areas of the 3D model will be examined for detailed dynamic thermal

Figure 4. 3: IES Applications

User Interface.



modelling and which will not be included the output of direct results respectively. As

shown in figure 4.4 below the user interface enables the selection of the room

function upon Modelling of the room.

The next step in defining the room parameters is the assignment of room templates.

The room templates define a number of user defined pre-set values as shown below:

Room Attributes

Constructions

MacroFlo Opening Types

Thermal Conditions

A detailed account of the room templates for both the area and double skin façade

cavity used within the dynamic thermal modelling analysis can be a seen in

Appendix 2 (Figure 2.1-2.2). The IES 3D Hawkins House Redevelopment model can

be seen in figure 4.6 below, highlighting the ‘’room’’ function defined office area and

‘’adjacent building’’ defined redevelopment.

Figure 4. 4: IES Room Function Interface. The office area (in green) and additional Hawkins House redevelopment (pink) is highlighted above.

Figure 4. 5: IES Room Template Interface.



Figure 4. 6: Hawkins House Redevelopment 3D IES Virtual Environment Model.

4.2.2 Conventional Single-Skin Façade – Base Model Analysis

In order to achieve a high level of result

integrity an initial analysis using a

conventional single-skin façade will be

carried out on the Office Area. This step

is necessary to provide a comparable

base energy consumption value and as

a result to calcite the efficiency, or

inefficiency of each respective Double-

Skin Façade system to be examined. In

order to achieve maximum comparability

the conventional single-skin façade will

be of the same wall construction as each respective Double-Skin Façade systems

internal skin. The single-skin base model is shown above in figure 4.7.

The ‘’Drum’’ Office Area –

Room Function

Redevelopment – Adjacent Building Function

Figure 4. 7: Hawkins House Redevelopment IES 3D

Base Model.



4.2.3 Double-Skin Façade Configurations

In order to provide an accurate and extensive critical analysis of Double-Skin Façade

energy consumption, a wide range of variations and permutations are to be

examined. The variations which are to examined can be defined under the following

three headings:

1. Double-Skin Façade Type.

2. Double Skin Façade System.

3. Depth of the Double Skin Façade Cavity.

As previously described in Chapter 2, the four main methods of classification of

Double-Skin Façade are as follows:

Box Façade Corridor Façade Shaft-Box Façade Multi-Storey Façade

Each type of Double-Skin Façade will be assessed by varying the configuration of

the cavity within the IES 3D model. Google SketchUp models of the various

configurations to be examined are shown above in figures 4.8 - 4.11.

In addition to each Double-Skin Façade configuration, there are a number of cavity

system variations to be examined. As previously described in Chapter 3, the three

main system variations are as follows:

A Naturally Ventilated Cavity.

A Sealed Cavity.

A Regulating (mixed-mode ventilation) Cavity.

Figure 4. 11: Box

Façade

Figure 4. 8: Corridor Façade Figure 4. 10: Shaft-Box Façade

Figure 4. 9: Multi-Storey Façade



Accordingly each respective system was created within the IES MacroFlo Openings

Database Manager. This allows for a detailed composition of ventilation openings

and window systems as required. A detailed account of the MacroFlo Opening

Profiles for the various Double-Skin Façade cavity systems used within the dynamic

thermal modelling analysis can be a seen in Appendix 2 (figure 2.3-2.5).

In addition to the variations in Double-Skin Façade configuration and system to be

assessed, the effect of the depth of the cavity on energy consumption within the

office area will also be examined. The dimensions of the cavity to be assessed are

as follows:

200mm.

600mm.

1000mm.

A broad range of depths (400mm variation in each) is to be examined in order to

achieve a large spectrum of results and to determine the effect of varying the cavity

depth.

4.3 Analysis / Simulations

Upon completion of the 3D model in the Model IT interface, the next step is to run

the various additional IES components in order to generate detailed experimental

result outputs.

4.3.1 SunCast

The purpose of SunCast is to analyse the way in which solar gains impact the

building. These impacts are also quantified in terms of heat gains and energy

consumption within the

building for later integration

with ApacheSim. The use of

SunCast as a method of

calculating annual solar

shading calculations is shown

in figure 4.12:

Calculation Parameters Interface

Solar Shading Calculations Output Figure 4. 12: IES SunCast – Solar Shading Calculations.



4.3.2 ApacheSim

The purpose of ApacheSim is to model dynamic interactions between the building,

the external climate, the internal loads and processes and the building mechanical

systems. It integrates information generated from additional IES applications and

performs detailed performance simulations. It is within this application that detailed

analysis in relation to energy consumption will be calculated on the ‘’Drum’’ office

area. The user interface for setting the parameters of using the ApacheSim

application is shown below in figure 4.13.

4.3.3 Vista Results Analysis

Vista Results Analysis is located under the thermal group of applications within the

IES Virtual Environment suite. Its primary function is to act as a tool which is efficient

and easy to analyse the results from one or more simulations carried out using the

dynamic thermal modelling tools within IES. In figure 4.14, the user interface for the

comparison of dynamic thermal modelling is shown.

Vista Results Analysis Calculations Output

Results Parameter Interface

Figure 4. 13: ApacheSim Parameters User Interface.

Figure 4. 14: Vista Results Analysis Interface.



4.3.4 MacroFlo

The primary function of the MacroFlo application is for analysing infiltration and

natural ventilation in buildings. It utilises a zonal airflow model to calculate air

movement in and through the building, driven by wind and buoyancy induced

pressures. For the purpose of comparing various Double-Skin Façade cavity airflow

systems, MacroFlo enables the input of data such as air flow characteristics, opening

profile, etc. which is necessary for an effective comparison of the various cavity

airflow systems. As previously mentioned in 4.2.2 the type of Double Skin Façade

systems to be examined comprise of naturally ventilated, sealed and regulating

(mixed-mode) cavities. The user interface of the MacroFlo Openings Database

Manager is shown below in 4.15.

In conclusion, through the use of each IES application as mentioned above the aim

of performing dynamic thermal calculations is to determine if Double-Skin Façade

construction provides a viable solution to reduce overall energy consumption as

opposed to a conventional single-skin façade.

Figure 4. 15: MacroFlo Openings Database Manager Interface.

Chapter 5 Dynamic Thermal Modelling Simulations


0 10 20 30 40 50 60 70

Naturally Ventilated Cavity

Sealed Cavity

Regulating Cavity


Sealed Cavity

Regulating Cavity


Sealed Cavity

Regulating Cavity

Bas

e M

od

el

20

0m

m

60

0m

m

10

00

mm

Base Model 200mm 600mm 1000mm Naturally

Ventilated Cavity

Sealed Cavity Regulating

Cavity

Naturally Ventilated

Cavity Sealed Cavity

Regulating Cavity


Cavity Sealed Cavity

Regulating Cavity

Multi-Storey Façade 36.767 39.411 39.034 38.098 33.385 32.865 38.106 33.149 32.585

Shaft-Box Façade 47.258 42.419 42.268 49.645 42.968 42.697 61.625 38.836 38.509

Corridor Façade 39.509 34.302 33.680 40.340 34.482 33.801 41.568 35.329 34.588

Box Façade 38.817 34.164 33.810 41.812 35.335 34.936 44.011 36.097 35.774

Base Model 38.6719

Annual Energy Consumption (mWh) 5.0 Dynamic Thermal Modelling Simulations

As described in the previous chapter the aim of performing

dynamic thermal modelling calculations is to carry out a

comparative analysis of the effect on energy consumption

within the ‘’Drum’’ office area and to identify the most energy

efficient configuration in terms of the set parameters. In this

chapter the results obtained through the parametric analysis

on Double-Skin Façade energy performance are presented.

5.1 Analysis of Simulation Results

The overall energy consumption within the office area is

evaluated under the effect on heating and cooling loads in

relation to the use of various combinations of Double-Skin

Façade configurations, systems and depths. In order to

provide an accurate comparison of results, the energy

consumption related to heating and cooling loads for a

conventional single-skin façade is also evaluated (as

previously described in Chapter 4 – 4.2.2).

5.1.1 Annual Energy Consumption (mWh)

The annual energy consumption of each respective Double-

Skin Façade configuration, system and varying cavity depth

examined is shown to the right in Figure 5.1.

For the purpose of clarity each method of Double-Skin

Façade configuration, system and depth examined are

presented as a group in order to quickly determine the

efficiency of each system and to highlight any potentially

inefficient variations in terms of annual energy consumption.

Please refer to Appendix 3 (figure 3.1) for an additional

detailed analysis and account of the office annual energy

consumption for each of the respective simulations

performed.

Figure 5. 1: Annual Energy Consumption – Dynamic Thermal Modelling Simulations.



0

10000

20000

30000

40000

50000

60000

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Base Model 200mm Naturally Ventilated Cavity

200mm Sealed Cavity 200mm Regulating Cavity

200mm Cavity Depth

Base Model Box Façade Corridor Façade Shaft-Box Façade Multi-Storey Façade

As previously discussed, detailed dynamic thermal simulations were carried out on

each method of Double-Skin Façade configuration, system and depth as mentioned

below:

Double-Skin Façade Configuration.

Double-Skin Façade Cavity Airflow System.

Double Skin Façade Cavity Depth.

In order to determine the most efficient combination of the Double-Skin Façade

variations examined, a detailed analysis of each configuration, system and cavity

depth are presented below.

5.1.2 Annual Heating and Cooling Loads (kWh)

A detailed examination of the annual heating and cooling loads (kWh) of the office

area of each respective Double-Skin Façade configuration and system are presented

below. Each are defined under the various cavity depths used within the dynamic

thermal modelling simulations.

Figure 5. 2: Annual Heating and Cooling Loads - 200mm Cavity Depth.



0

10000

20000

30000

40000

50000

60000

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)



600mm Cavity Depth


0

10000

20000

30000

40000

50000

60000

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)

Annual Heating

Load (kWh)

Annual Cooling

Load (kWh)



1000mm Cavity Depth






Upon initial review of the annual heating and cooling loads (kWh) within the office

area of the Hawkins House Redevelopment, it is clear that the conventional single-

skin façade base model has a greater demand on annual cooling loads than that of

heating loads.

However, in each of the various Double-Skin Façade simulations carried out it is

clear that the annual heating load demand is substationally greater than that of the

cooling load. This would suggest that although the heating demand associated with a

Double-Skin Façade is increased compared to a conventional single-skin façade, the

concept of a thermal buffer utilising the stack effect to remove excessive heat within

the cavity reduces the cooling loads significantly.

Due to this fact, overall annual energy consumption in relation to Double-Skin

Façade construction may be greater than that of a conventional single-skin façade

due to the increased heating loads. However, According to The European Energy

(Portal., 2013), as of November 2012 in Ireland, Industry prices per kWh for natural

gas (heating demands) and electricity (cooling demands) are €0.03852 and

€0.09618 respectively. This is an important economical aspect to consider as the

costs associated with the heating and cooling of a building has a ratio of

approximately 3:1. As a result, due the increased cooling load demand of a

conventional single-skin façade construction, the use of a Double-Skin Façade in

reality still provides a more cost effective method of façade construction in terms of

consumption of energy. A detailed account of the annual cost, and loads in relation

to energy consumption of each scenario can be seen in Appendix 3 (table 3.3-3.14).

5.1.3 Annual Energy Consumption (kWh/m²)

The annual energy consumption within the office area of the Hawkins House

redevelopment is presented below under the various Double-Skin Façade

configurations evaluated (A Box Façade, Corrdidor Façade and a Multi-Storey

Façade configuration).

The results are presented as per square metre of floor area (total floor area

852.44m²) This is necessary in order to determine and easily compare the overall

performance of each Double-Skin Façade configuration in greater detail.



Base Model 200mm 600mm 1000mm

Base Model 45.366

Naturally Ventilated 45.536 49.049 51.629

Sealed Cavity 40.077 41.452 42.345

Regulating Cavity 39.662 40.984 41.967

0.000

10.000

20.000

30.000

40.000

50.000

60.000

70.000

80.000

An

nu

al E

ne

rgy

Co

nsu

mp

tio

n (

Kw

h/m

²)

Box Façade


Base Model 45.366


Sealed Cavity 40.239 40.451 41.445


0.000

10.000

20.000

30.000

40.000

50.000

60.000

70.000

80.000

An

nu

al E

ne

rgy

Co

nsu

mp

tio

n (

Kw

h/m

²) Corridor Façade

Figure 5. 5: Box Façade – Annual Energy Consumption (kWh/m²).

Figure 5. 6: Corridor Façade – Annual Energy Consumption (kWh/m²).




Base Model 45.366


Sealed Cavity 49.762 50.406 45.559


0.000

10.000

20.000

30.000

40.000

50.000

60.000

70.000

80.000

An

nu

al E

ne

rgy

Co

nsu

mp

tio

n (

Kw

h/m

²)

Shaft-Box Façade


Base Model 45.366


Sealed Cavity 46.234 39.164 38.887


0.000

10.000

20.000

30.000

40.000

50.000

60.000

70.000

80.000

An

nu

al E

ne

rgy

Co

nsu

mp

tio

n (

Kw

h/m

²)

Multi-Storey Façade

Figure 5. 7: Shaft-Box Façade – Annual Energy Consumption (kWh/m²).

Figure 5. 8: Multi-Storey Façade – Annual Energy Consumption (kWh/m²).



Upon review of the annual energy consumption of each Double-Skin Facade

configuration examined within the office area of the Hawkins House Redevelopment,

it is clear that the configuration which is performing the least efficiently in terms of

annual energy consumption is the Shaft-Box Façade configuration.

As such, the least efficient variation of the Shaft-Box Façade configuration examined

is the 1000mm naturally ventilated cavity. The annual energy consumption has a

value of 72.292 kWh/m², approximately 62% less efficient than the conventional

single-skin base model (45.366 kWh/m²).

As highlighted in Appendix 3 (table 3.5) the detailed cost analysis highlights that this

elevated value is attributed to by high annual heat loading demands (54,757.8 kWh)

and as a result, is the only configuration which is more expensive per annum than

the base model of the conventional single-skin façade.

Due to the nature of the Shaft-Box Façade, ie. dependent on various shafts to induce

the stack effect and cause air flow from the box elements in order to remove

excessive heat from the cavity (see figure 5.9). The high heating load may be as a

result of excessive airflow through the cavity due to a combination of the elevated

exposed façade of the office are (wind effects) and due to the large depth (1000mm)

of the naturally ventilated cavity.

In conclusion, the various dynamic

thermal modelling simulations carried

out on each respective Double-Skin

Façade configuration, cavity airflow

system and depth are presented above.

Through the results obtained from the

simulations, the optimal combination of

Double-Skin Façade construction is to

be identified in order to provide a

quantified conclusion on the most

efficient method of construction for use

within a temperate climate.

Figure 5. 9: Shaft-Box Façade Configuration – Airflow Concept.

6.0 Conclusions and Recommendations



Through the results obtained within the dynamic thermal modelling simulations, as

discussed in the previous chapter, this chapter aims to provide a recommendation as

to which is the most energy efficient combination of Double-Skin Façade

configuration, system and depth of cavity to be utilised in an office building in a

temperate climate.

6.1 Comparison of Façade Configuration Energy Consumption

As highlighted within the various results in the previous chapter, the annual energy

consumption (kWh/m²) within the office area of the Hawkins House redevelopment

was presented under each of the four Double-Skin Façade configurations evaluated

within the dynamic thermal modelling simulations (see figures 5.5-5.8).

In order to determine which Double-Skin Façade configuration and cavity airflow

system is achieving the highest degree of efficiency in relation to energy

consumption, each of the best case scenarios from the four figures of results in

relation to façade configuration are shown together below in Table 6.1:

Figure 6. 1: Annual Energy Consumption – Facade Efficiency Comparison.

Box Façade Corridor Façade

Shaft-Box Façade


Regulating Cavity 200mm 39.662 39.510

Regulating Cavity 1000mm 45.175 38.226

34.000

36.000

38.000

40.000

42.000

44.000

46.000

An

nu

al E

ne

rgy

Co

nsu

mp

tio

n (

kWh

/m²)

Façade Efficiency



200mm 600mm 1000mm 1200mm 1400mm 1800mm

Multi-Storey Façade 45.791 38.554 38.226 38.201 38.312 38.937

34.000

36.000

38.000

40.000

42.000

44.000

46.000

48.000

An

nu

al E

ne

rgy

Co

nsu

mp

tio

n (

kWh

/m²)

Multi-Storey Façade - Optimal Cavity Depth

As indicated above, each of the best case scenarios of the Double-Skin Façade

configurations and systems evaluated are utilising a regulating cavity, underlining its

efficiency as opposed to the utilisation of a naturally ventilated or sealed cavity.

However, the 1000mm Multi-Storey Double-Skin Façade with a regulating cavity is

the most efficient façade construction combination evaluated. This combination

achieved an annual energy consumption value of 38.226 kWh/m², an increase in

efficiency of approximately 16% as opposed to the base model utilising a

conventional single-skin façade (45.366 kWh/m²).

In order to determine the most efficient combination of the Multi-Storey Double-Skin

Façade with a regulating cavity in terms of energy consumption a number of

additional dynamic thermal modelling simulations were undertaken at increased

cavity depths of 1200mm, 1400mm and finally 1800mm. These calculations were

performed to identify and establish the optimal depth of the cavity in terms of energy

consumption. A comparison of the energy consumption in relation to the cavity

depths is shown below in table 6.2:

Figure 6. 2: Multi-Storey Façade Regulating Cavity – Determination of Optimal Cavity Depth.



0.00 500.00 1000.00 1500.00 2000.00 2500.00 3000.00

1000mm

1200mm

Base Model

Annual Energy Consumption Cost (€)

1000mm 1200mm Base Model

Base Model 2711.34

Multi-Storey Cavity 1624.76 1636.19

Multi-Storey Façade - Optimal Cavity Depth

As indicated above in figure 6.2, the optimal cavity depth of the Multi-Storey Double-

Skin Façade with a regulating cavity is located at a depth of approximately 1100mm.

Initially, the graph indicates a steady increase in energy efficiency of the Double-Skin

Façade between the respective depths of 200mm and 600mm. The energy efficiency

then gradually begins to stabilise between the respective depths of 600mm and

1200mm, before reducing in efficiency at an approximate depth of 1200mm. A

steady decrease in efficiency between the respective depths of 1200mm and

1400mm becomes considerably more substantial beyond a depth of 1400mm to

1800mm.

This trend indicates that beyond a certain depth of cavity (1200mm) the efficiency of

the Double-Skin Façade begins to decrease, becoming less efficient the greater the

depth, thus highlighting the importance of the need for careful consideration when

designing the dimensional parameters of a Double-Skin Façade construction.

However, even though the optimal cavity depth of the Multi-Storey Double-Skin

Façade with a regulating cavity is approximately 1100mm, there is only a relatively

small difference in terms of annual energy consumption between a cavity of 1000mm

and 1200mm (25 kWh/m²).

As such, further exploration in relation to the annual cost (€) of the office area in

relation to energy consumption of each depth is shown below in figure 6.3:

Figure 6. 3: Annual Energy Consumption Cost – Optimal Cavity Depth.



As highlighted above in figure 6.3, the difference in cost of the annual energy

consumption between the 1000mm and 1200mm Multi-Storey regulating cavity is a

relatively unimpressive €11.43.

However, a substantial difference in the cost of annual energy consumption of the

office area of €1,086.58 exists between the 1000mm cavity depth and the

conventional single-skin façade base model.

This indicates a substantial improvement of 31% in annual energy efficiency

between the conventional single-skin façade base model and the Multi-Storey

Double-Skin Façade with a 1000mm regulating cavity system.

6.2 Recommendations – Optimum Cavity Depth

The primary aim of this research was to determine and evaluate the effect in which

various configurations, systems and cavity depths of Double-Skin Façade

construction plays in relation to overall the energy consumption of an office building

within a temperate climate.

Additionally, to establish and determine the optimal combination of Double-Skin

Façade configuration, cavity airflow system and cavity depth in relation to overall

building energy consumption for use within the façade of the office area of the

Hawkins House redevelopment.

Through the careful analysis of the results of the simulations of the dynamic thermal

modelling of the variations and combinations of Double-Skin Façade construction, it

is clear that the most efficient method of Double-Skin Façade construction for use

within the office area of the Redevelopment of Hawkins Hawkins House is comprised

of the following main parameters:

A Multi-Storey Double Skin Façade Configuration.

A Regulating (mixed mode) cavity ventilation system.

A 1000mm cavity depth.

In conclusion, this combination of Double-Skin Façade construction provides

increased annual percentage efficiency in terms of energy consumption of 31%, and

a substantial cost saving of €1,086.58 as opposed to the use of a conventional

single-skin façade.



6.3 Areas for Further Research

Double-Skin Façade construction has excellent potential for a further decrease in

overall building energy consumption in a wide range of research areas. Some of the

main areas for further thought and research arising from this dissertation are:

The potential harnessing of heat generated within the Double-Skin Façade cavity for

reintegration within the building. As the temperature within the cavity can reach

extremely high temperatures, the ability to collect such heat is a viable option as

opposed to releasing the heat generated back into the environment. This can be

achieved through various methods in which the overall energy consumption of the

building can be decreased further, such as:

The use of phase-change materials.

The use of mechanical heat recovery systems.

Another viable method of potentially reducing overall building energy consumption is

the use and integration of photovoltaic panels within the external skin of the Double-

Skin Façade. This is an interesting area of further research as the high levels solar of

exposure in which double-skin facades receive provides an ideal situation for the

collection of solar energy and generation of electricity while also providing often

much needed solar shading to the building interior.

Another area of further research in

which the possibility of building

energy consumption can be

decreased is through the use of an

external skin comprised of

horizontal slats of transparent and

translucent glass (see figure 6.4).

The orientation of this method of

external skin configuration is

regulated by the use of a building

management system and as such

construction protects the interior of

building from large amounts of solar

radiation and thus regulates the interior temperature reducing overall cooling loads.

Figure 6. 4: Horizontal Pivoting Transparent Slats (Teuxido,

2013).

References


References

12792., B. E. (2003). Ventilation for buildings, Symbols, terminology and graphical symbols.

Aksamija, A. Context Based Design of Double Skin Facades: Perkins + Will Research Journal.

ArchiExpo. (2003). from http://archiexpo.com/prod/feal-croatia-itd/ventilated-aluminium-facades-57866-587842.html

Arons, D. (2000). Properties and Applications of Double-Skin Building Facades. Massachusetts Institute of Technology.

Baker, N. (2013). Natural ventilation - stack ventilation. from http://www.architecture.com/SustainabilityHub/Designstrategies/Air/1-2-1-2-Naturalventilation-stackventilation.aspx

Bayram, A. (2003). Energy Performance of Double Skin Facades In Intelligent Office Buildings: A Case Study in Germany., The Middle East Technical University.

BBRI, B. B. R. I. (2004). Ventilated Double Facades - Classification and Illustration of Facade Concepts: Department of Building Physics, Indoor Climate and Building Services.

Caine, T. (2013). Green Buildings: The Cambridge Public Library. Consultants, B. (2013). Building Envelope. from

http://www.bauerconsultbotswana.com/7_BuildingEnvelope.pdf Crespo, A. M. L. (2002). History of the Double-Skin Facade: Harvard School of

Design. Dickson, A. (2003). Modelling Double-Skin Facades. University of Strathclyde,

Glasgow, Scotland. Gonchar, J. (2013). More Than Skin Deep | From Architectural Record | Originally

published in the July 2010 issue of Architectural Record | Architectural Record's Continuing Education Center. from http://continuingeducation.construction.com/article.php?L=5&C=685&P=4

Heimrath, R., Hengsberger, H., Mach, T., Streicher, W., & Waldner, R. (2005). Best Practice for Double-Skin Facades: Institute of Thermal Engineering, Graz University of Technology.

King, D. (2010). Engineering a Low Carbon Built Environment. London: The Royal Academy of Engineering.

Lee, E., Selkowitz, S., Bazjanac, V., Inkarojrit, V., & Kohler, C. (2002). High-Performance Commercial facades: Ernest Orlando lawerence Berkeley National Laboratory.

Oesterle, E., Lieb, R.-D., Lutz, M., & Heusler, W. (2001). Double-Skin Facades - Integrated Planning: Prestel.

Palmer, D. (2011). A Decision Making tool, Guidance and Considerations to Optimise Energy Consumption and Occupant Comfort when Replacing Facades on Exisiting Buildings. The University of Bath., Bath.

Permasteelisa, G. (2013). Closed Cavity Facades. from http://josef-gartner.permasteelisagroup.com/about-gartner/products-services/closed-cavity-facades/

Poizaris, H. (2006). Double-Skin Facades - A literature Review: Lund University, Lund Institute of Technology.

Portal., E. E. (2013). Renewable energy in final energy consumption. from http://www.energy.eu/

http://archiexpo.com/prod/feal-croatia-itd/ventilated-aluminium-facades-57866-587842.html

http://archiexpo.com/prod/feal-croatia-itd/ventilated-aluminium-facades-57866-587842.html

http://www.architecture.com/SustainabilityHub/Designstrategies/Air/1-2-1-2-Naturalventilation-stackventilation.aspx

http://www.architecture.com/SustainabilityHub/Designstrategies/Air/1-2-1-2-Naturalventilation-stackventilation.aspx

http://www.bauerconsultbotswana.com/7_BuildingEnvelope.pdf

http://continuingeducation.construction.com/article.php?L=5&C=685&P=4

http://josef-gartner.permasteelisagroup.com/about-gartner/products-services/closed-cavity-facades/



http://www.energy.eu/

References


Saelens, D. (2002). Energy Performance Assessment of Single Story Multiple-Skin Facades.

Solla, I. F. (2013). Façades Confidential: 11/01/2011 - 12/01/2011. from http://facadesconfidential.blogspot.ie/2011_11_01_archive.html

Streicher, W., Heimrath, R., Hengsberger, H., Mach, T., Waidner, R., Flamant, G., et al. (2007). On the Typology, Costs, Energy Performance, Environmental Quality and Operational Characteristics of Double Skin Facades in European Buildings. [Article]. Advances in Building Energy Research, 1, 1-28.

Tascón, & Hernandez., M. (2008). Experimental And Computational Evaluation Of Thermal Performance And Overheating In Double Skin Facades: University of Nottingham.

Teuxido, C. (2013). Double skin façade of Agbar Tower in Barcelona, by Jean Nouvel [226].

Uuttu, S. (2001). Study of Current Structures in Double-Skin Facades. Helsinki University of Technology, Helsinki.

Wolfe, R. (2013). The Sociohistoric Mission of Modernist Architecture:.

http://facadesconfidential.blogspot.ie/2011_11_01_archive.html

Appendix 1


Appendix 1: The History of Double-Skin Façades

Although the concept of Double-Skin Façades is not new, there is a growing

tendency within the construction industry for architects and engineers to incorporate

them into projects. Information on the history of Double-Skin Façades can be

obtained through a wide range of articles, books, reports, etc.

However according to (Saelens, 2002) in 1849, Jean-Baptiste Jobard, the director of

The Industrial Museum in Brussels, was the first person to describe the idea of a

mechanically ventilated multiple-skin façade. He mentioned his theory of how ‘’in

winter hot air should be circulated between two glazing, while in summer it should be

cold air’’. His theory however is not mentioned for another 65 years. In 1914, Paul

Scheerbaert mentions a similar idea in his book “Glasarchitectur”.

It is apparent that as early as the 19th

century consideration was given to the

performance of buildings, especially in

terms of thermal performance. One can

still find an example of this in old

farmhouses with box-type windows in

Mürren, Switzerland. It is possible to open

the box windows but also remove the outer

casements completely. They are

constructed in such a manner that in

summer, the inner-casements can be opened and the outer layer of glazing

removed. This allows an adaptation of the building envelope to the climatic

conditions (Oesterle, et al., 2001).

The first example of a Double-Skin wall

construction can be found from the year

1903 in the Steiff Factory in Giengen,

Germany. The aim of the project was to

maximise day lighting but to also to

provide protection from the harsh climate

Appendix 1. 2: Famhouse Box-Type Windows in

Mürren, Switzerland (Oesterle, et al., 2001).

Appendix 1. 1: Steiff Factory Giengen, Germany. Circa 1904 (Solla, 2013).

Appendix 1


of the region. In order to achieve these goals a three storey structure was erected. It

comprised of a ground floor acting as storage space with two upper floors as work

areas. The building was regarded as a complete success and thus two extensions

were built in 1904 and 1908. They were constructed using the same double-skin

façade construction method but timber was used as the main structural material due

to budgetary reasons. All buildings are still in use today (Heimrath, Hengsberger,

Mach, Streicher, & Waldner, 2005).

Also in the year 1903, the Post Office Savings Bank in Vienna, Austria, held a

competition for the design of its main building. Otto Wagner won the competition and

the bank was built in two construction phases from 1904 to 1912. It contained a

double-skin aluminium skylight supported by steel columns in the main hall (Poizaris,

2006).

By the end of the 1920’s, double-skin façades began to advance with other

considerations in mind. There are two main examples which can be used to highlight

this (Uuttu, 2001).

In 1928 in Russia, Moisei Ginzburg

investigated the possible use of double-

skin sections in the communal service

blocks of the Narkomfin housing building,

in Moscow. Ginzburg was very interested

in the technical aspects of windows and

how to achieve greater performance

standards (Uuttu, 2001).

Also at the same time in Moscow, Le Corbusier was in the

process of designing the Centrosoyus. The following year in

Paris he would then undertake the design of La Cité de

Refuge and the Immeuble Clarte. Each of the initial projects

were designed with Le Corbusier concept of ‘’mûr

neutralisant’’. His theory predicted that the transmission

losses and gains would disappear by the circulation of air at

room temperature through the building cavity. However his

Appendix 1. 3: Narkomfin Housing Building, Moscow,

Russia. Circa 1928 (Wolfe, 2013).

Appendix 1. 4: Corbusier Sketch

Illustrating Ideas (Tascón & Hernandez., 2008).

Appendix 1


system was deemed as too expensive and inefficient to build and thus the idea was

abandoned (Saelens, 2002).

However, there was then little or no progress made in double-skin façade

construction up until the late 70’s and early 80’s of the century (Poizaris, 2006). The

oil crisis’ of 1973 and 1979 had a positive effect and resulted in a boost on the

development rate of insulating glazing as greater awareness on energy consumption

became evident. Many innovative improvements to the technology were made with

the introduction of low-emissivity coating and inert gas filled cavities. In the same

period an awareness grew on the effects of external shading, thermal mass and the

role of ventilation in relation to building performance standards (Dickson, 2003).

During the 80’s double-skin façades finally began to gain momentum within the

construction industry. Most of the façades constructed during this era were designed

with consideration to environmental factors, such as the offices of Leslie and

Godwin, or with the aesthetic effect of multiple layers of glass (Poizaris, 2006).

During the 90’s there were two main factors which began to have a large influence of

the proliferation of double-skin façades. The increase of environmental concerns

began to influence architectural design not only from a technical standpoint but also

due to political influences that make ‘’green buildings’’ a good image for corporate

architecture. In addition the rapid development of software and hardware allowed

designers to carry out highly complex calculations in order to effectively design

façades (Heimrath, et al., 2005).

As a result these factors make double-skin façades an ideal option for use in high

rise buildings. Typically they are provided with a large budget and the aim of

achieving an environmentally friendly image. Another aspect which makes them

particularly effective with high-rise buildings is the fact that a double-skin façade

allows windows to be opened despite strong wind conditions incurred on certain

floors due to their height within the building.

Examples of such can be found in RWE AG Headquarters by Ingenhoven, Overdiek

Kahlen und Partner, the Commerzbank Headquarters by Foster and Partners, both

of which were completed in Germany in 1997. The work of Renzo Piano in the Debis

Tower in 1998 is a less extreme example of this tendency. The firm carried out a

Appendix 1


thorough environmental analysis of the façades in the building. As a result the idea

of creating an environmentally friendly skyscraper was progressed by the concept of

allowing the skin to adapt to the individual requirements (Crespo, 2002).

Appendix 2


Appendix 2: IES Virtual Environment User Interface

Appendix 2. 1: Office Room Conditions.

Appendix 2. 2: Double-Skin Façade Room Conditions.

Appendix 2


Appendix 2. 4: Double-Skin Façade MacroFlo Opening Template – Naturally ventilated Cavity.

Appendix 2. 3: Double-Skin Façade MacroFlo Opening Template – Sealed Cavity.

Appendix 2


Appendix 2. 5: Double-Skin Façade MacroFlo Opening Template – Regulating Cavity.

Appendix 3


Base Model

Box Façade

Corridor Façade

Shaft-Box Façade


0

10

20

30

40

50

60

70


Cavity


Cavity Naturally

Ventilated Cavity


Cavity Naturally

Ventilated Cavity


Cavity

Base Model 200mm

600mm

1000mm

Base Model

Box Façade

Corridor Façade

Shaft-Box Façade


Appendix 3: Double-Skin Façade – Energy Consumption

and Cost Analysis

A detailed analysis of the various results obtained within the

thermal dynamic simulations is highlighted within the current

appendix, in addition to a number of detailed cost analysis

calculations. The results obtained include:

Natural Gas Consumption (kWh).

Electricity Consumption (kWh).

Annual Energy Consumption (mWh).

Annual Energy Consumption (kWh/m²).

Annual Energy Consumption Cost (€).

Percentage Efficiency (Opposed to Base Model).

An overview of the annual energy consumption (mWh) of each

respective Double-Skin Façade combinations is available to the

right in Appendix 3 Figure 3.1.

Dublin Experimental Parameters

Building Area (m²) 852.44 Natural Gas Price (€) 0.03852 Electricity Price (€) 0.09618

Project Baseline (kwh/m²) 110, 210 Appendix Table 3.1: Base Model Experimental Parameters

Dublin (Curtain Wall Construction) Cost (€) Natural Gas Consumption (kWh) 17484

€ 673.48

Electricity Consumption (kWh) 21187.9

€ 2,037.85

Annual Energy Consumption (mWh) 38.6719

€ 2,711.34

Energy Consumption ( kWh/m²) 45.36612548

€ 3.18

Appendix Table 3.2: Base Model Examination.

Appendix 3. 1: Annual Energy Consumption Overview (mWh).

Appendix 3


Dublin (200mm Naturally Ventilated Cavity)

Façade Configuration Natural Gas Consumption

(kWh) Electricity Consumption (kWh) Annual Energy Consumption (mWh) Energy Consumption (kWh/m²) Annual Cost (€)

Box Facade 32001.7 6815 38.8167 45.5359908 €

1,888.17

Corridor Facade 32795.5 6713.8 39.5093 46.348482 €

1,909.02

Shaft-Box Facade 40623.9 6634.3 47.2582 55.43874056 €

2,202.92

Multi-Storey Facade 30563.1 6204 36.7671 43.1315987 €

1,773.99 Appendix Table 3.3: IES Test Results

Dublin (600mm Naturally Ventilated Cavity)



Box Facade 35227.6 6583.9 41.8115 49.04919994 €

1,990.21

Corridor Facade 33778 6562 40.34 47.32297874 €

1,932.26

Shaft-Box Facade 42999 6645.5 49.6445 58.23811647 €

2,295.49

Multi-Storey Facade 31724.1 6373.4 38.0975 44.69229506 €

1,835.01 Appendix Table 3.4: IES Test Results Dublin (1000mm Naturally Ventilated Cavity)



Box Facade 37432.6 6578.4 44.011 51.6294402 €

2,074.61

Corridor Facade 35048.4 6519.9 41.5683 48.76390127 €

1,977.15

Shaft-Box Facade 54757.8 6866.9 61.6247 72.29212613 €

2,769.73


1,831.38

Appendix 3


Appendix Table 3.5: IES Test Results

Dublin (200mm Sealed Cavity)



Box Facade 26065.3 8098.3 34.1636 40.0774248 €

1,782.93

Corridor Facade 26500.1 7801.4 34.3015 40.23919572 €

1,771.12

Shaft-Box Facade 35437.4 6981.8 42.4192 49.76209469 €

2,036.56

Multi-Storey Facade 32331 7080.3 39.4113 46.2335179 €





Box Facade 27754.6 7580.8 35.3354 41.45206701 €

1,798.23

Corridor Facade 26992.5 7489.3 34.4818 40.45070621 €

1,760.07

Shaft-Box Facade 36119.5 6848.9 42.9684 50.40636291 €

2,050.05






Box Facade 28779.1 7317.4 36.0965 42.34491577 €

1,812.36

Corridor Facade 27933.2 7395.9 35.3291 41.44467646 €

1,787.32

Shaft-Box Facade 32049.6 6786.3 38.8359 45.55851438 €

1,887.26


1,680.29


Appendix 3


Dublin (200mm Regulating Cavity)



Box Facade 26364 7445.7 33.8097 39.66226362 €

1,731.67

Corridor Facade 26525.4 7154.1 33.6795 39.5095256 €

1,709.84

Shaft-Box Facade 35574.5 6693.3 42.2678 49.58448688 €

2,014.09






Box Facade 28170.1 6766.3 34.9364 40.98399887 €

1,735.89

Corridor Facade 27015 6786.3 33.8013 39.65240955 €

1,693.32

Shaft-Box Facade 36259 6438.3 42.6973 50.08833466 €

2,015.93






Box Facade 29326.5 6447.6 35.7741 41.96670733 €

1,749.79

Corridor Facade 27955.7 6632.6 34.5883 40.57564169 €

1,714.78

Shaft-Box Facade 32220.3 6288.8 38.5091 45.17514429 €

1,845.98


1,624.76


Appendix 3






Multi-Storey 25942 6622 32.564 38.2009291 €





Multi-Storey 26006 6652.4 32.6584 38.31167003 €





Multi-Storey 26584 6607.2 33.1912 38.93669936 €

1,659.50

a comparative analysis on the effect of double- skin...

Documents