Citation
Passive Survivability for Single Family Home Construction in Florida

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Title:
Passive Survivability for Single Family Home Construction in Florida
Creator:
Mejia, Andrew
Place of Publication:
[Gainesville, Fla.]
Publisher:
University of Florida
Publication Date:
Language:
english
Physical Description:
1 online resource (50 p.)

Thesis/Dissertation Information

Degree:
Master's ( M.S.B.C.)
Degree Grantor:
University of Florida
Degree Disciplines:
Building Construction
Committee Chair:
Kibert, Charles J.
Committee Co-Chair:
Olbina, Svetlana
Committee Members:
Grosskopf, Kevin R.
Graduation Date:
8/9/2008

Subjects

Subjects / Keywords:
Cisterns ( jstor )
Cooling ( jstor )
Heating ( jstor )
Homes ( jstor )
Natural ventilation ( jstor )
Rain ( jstor )
Roofs ( jstor )
Solar radiation ( jstor )
Utility rooms ( jstor )
Ventilation systems ( jstor )
Building Construction -- Dissertations, Academic -- UF
Genre:
Electronic Thesis or Dissertation
born-digital ( sobekcm )
Building Construction thesis, M.S.B.C.

Notes

Abstract:
Passive survivability is a building's ability to provide critical life support functions for the occupants while utility services are unavailable. This thesis covers the design and application of these elements, which when coupled together provide for a passively survivable house. Passive survivable houses can effectively minimize the potential aftereffect problems associated with natural and human caused disasters. Disasters such as the 1995 Chicago heat waves, which left over 600 hundred people dead, reaffirm the importance of passive survivability building design. These Chicago building's design flaws were their dependence on active ac systems, which when failure occurred, left apartment overnight temperatures above 90 degrees F. Primary intention of this research was to develop a model home that designers and builders could refer to for single-family home construction in Florida. The model home showcases how to adapt passively survivable technologies to suit the needs of a single family during a post disaster period. Secondary goal of this thesis was to design the various passively survivable systems to provide for a predetermined length of survivability. It was found that green construction technology research and design techniques contributed to the overall research content. Adapting and coupling these ideas together on a model home for a specific period of time led to some innovative design thoughts, highlighting the fact that designing for passive survivability is still in the early stages of development. Further research and development will encourage better design strategies increasing the effectiveness of passive survivability. ( en )
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Thesis:
Thesis (M.S.B.C.)--University of Florida, 2008.
Local:
Adviser: Kibert, Charles J.
Local:
Co-adviser: Olbina, Svetlana.
Statement of Responsibility:
by Andrew Mejia.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright Mejia, Andrew. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Classification:
LD1780 2008 ( lcc )

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1 PASSIVE SURVIVABILITY FOR SINGLE FAMILY HOME CONSTRUCTION IN FLORIDA By ANDREW JOSEPH MEJIA A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2008

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2 2008 Andrew Joseph Mejia

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3 To my family and friends.

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4 ACKNOWLEDGMENTS I would like to thank m y parents and family first and foremost for their loving support. I would also like to thank Dr. Kibert, for sparking my intere st in sustainable design and construction, along with Dr. Olbi na and Dr. Grosskopf for their guidance while serving on my supervisory committee. I would also like to thank Dr. Issa and Dottie Beaupied for all of their time and assistance that they have offered to me.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ............................................................................................................... 4 LIST OF FIGURES .........................................................................................................................7 ABSTRACT ...................................................................................................................... ...............8 CHAP TER 1 INTRODUCTION .................................................................................................................. 10 Introduction .................................................................................................................. ...........10 Problem Statement ............................................................................................................. .....10 Research Objectives ........................................................................................................... .....11 Scope and Limitations ......................................................................................................... ...11 2 LITERATURE REVIEW .......................................................................................................13 Introduction .................................................................................................................. ...........13 Heating ....................................................................................................................... .............13 Cooling ....................................................................................................................... ............14 Natural Ventilation .................................................................................................................16 Daylighting ................................................................................................................... ..........18 Photovoltaic Power .................................................................................................................19 Rain Water Collection ............................................................................................................20 3 RESEARCH METHODOLOGY ...........................................................................................27 Introduction .................................................................................................................. ...........27 Assumptions ................................................................................................................... ........27 Creating a Model .............................................................................................................. ......27 4 RESULTS ....................................................................................................................... ........29 Heating and Cooling ........................................................................................................... ....29 Natural Ventilation .................................................................................................................30 Daylighting ................................................................................................................... ..........31 Photovoltaic Solar Power Generation .....................................................................................32 Water .......................................................................................................................................34 Surviving in the Model Home ................................................................................................ 36 5 CONCLUSION .................................................................................................................... ...44 APPENDIX: PASSIVE SURVIVABILITY CHEKLIST ............................................................. 47

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6 LIST OF REFERENCES ...............................................................................................................48 BIOGRAPHICAL SKETCH .........................................................................................................50

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7 LIST OF FIGURES Figure page 2-1 Suns path in summer and winter....................................................................................... 22 2-2 Window overhang blocking sun ra diation during summer months ................................... 22 2-3 Window overhang allowing sun ra diation during winter m onths ...................................... 23 2-4 Summer/winter tree performance ...................................................................................... 23 2-5 Use of tall plants to maximize breeze and provide shade .................................................. 24 2-6 Stack effect ventilation .................................................................................................. ....24 2-7 Tube skylight ............................................................................................................. ........25 2-8 Thermal shade for clerestory windows .............................................................................. 25 4-1 Orientation of model home ................................................................................................ 38 4-2 Sun elevation for May 1st & October 1st ............................................................................38 4-3 Layout of model home ...................................................................................................... .39 4-4 South elevation landscaping plan .......................................................................................39 4-5 West elevation landscaping plan ........................................................................................40 4-6 In-roof installation of PV array ..........................................................................................40 4-7 Output data for PV system ................................................................................................. 41 4-8 Self-cleaning gutter component .........................................................................................41 4-9 Floating extraction filter ................................................................................................ ....42 4-10 Riser diagram of rainwater delivery system ...................................................................... 42 4-11 Utility room ............................................................................................................. ...........43

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8 Abstract of Thesis Presen ted to the Graduate School Of the University of Florida in Partial Fulfillment of the Requirements for the Master of Science in Building Construction PASSIVE SURVIVABILITY FOR SINGLE FAMILY HOME CONSTRUCTION IN FLORIDA By Andrew Joseph Mejia August 2008 Chair: Charles Kibert Cochair: Svetlana Olbina Major: Building Construction Passive survivability is a buildings ability to provide critical life support functions for the occupants while utility services are unavailabl e. Our Study addressed th e design and application of these elements, which when coupled together provide for a passively survivable house. Passive survivable houses can e ffectively minimize the potential aftereffect problems associated with natural and human caused disasters. Utility service downtime is the post disaster problem that this paper addresses. Our primary intention was to develop a model home that designers and builders could refer to for single-family home construction in Flor ida. The model home showcases how to adapt passively survivable technologies to suit the needs of a single family during a post disaster period. The secondary goal of this thesis was to design the various passively survivable systems to provide for a predetermined length of surv ivability. It was found that green construction technology research and design tech niques contributed to the overall research content. Adapting and coupling these ideas together on a model ho me for a specific period of time led to some innovative design thoughts, highlighting the fact that designing for passive surv ivability is still in

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9 the early stages of development. Further research and development will encourage better design strategies increasing the effectiv eness of passive survivability.

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10 CHAPTER 1 INTRODUCTION Introduction The m ost basic feature any building can provide for it occupants is shelter. One would say that almost all buildings today provide shelter, but what about when the buildings experience a power, gas, or water outage? These three com ponents are the lifeblood for any typical building today and, without them, inhabiting these buildings is almost impossible. Back in 1995 in Chicago a heat wave led to over 600 heat related deaths due to a combination of failures in buildings. With no wa y to naturally ventilate them, the buildings became ovens, leaving many struggling to survive inside their own homes. Buildings that were so dependant on city power for air conditioning became uninhabitable with indoor temperatures of 90F at night when the power failed. Problem Statement The problem with m ost buildi ngs today is that they are designed with a dependency on local utilities. This dependency can become cri ppling to building functions when utility service goes down. Natural gas and power distribution, especially, are exposed and vulnerable to failures, due to the remote location of centralized lines (Wilson 2005). Then, the question is why are we not designing our buildings to pr otect us 100 % of the time. This is why passive survivability needs to be addressed in the design stages of any building. Passive survivability was best defined by Alex Wilson (2005), the Executive Editor of Environmental Building News, as, the ability of a building to maintain critical life-support conditions for its occupants if services such as power, heating fuel, or water are lost for an extended period. Passive design, a green building concept, has many of the same features as survivability, an emergency management term The linking of these two concepts is an

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11 acknowledgement that green design inherently supports survivability and that they are complementary ideas. Passive survivability needs to become inte grated into building design. Passive solar heating and cooling, along with natural ventilation and dayligh ting are among the main ideas in surviving passively. Solar heating can be utilized in the winter and passive-cooling techniques can be utilized in the summer co mbined with natural ventilation. Natural daylighting is an important component because the inhabitants should be able to work during the daytime hours without need for electrical lighting. Rainwater ha rvesting becomes especially important because of the water crisis that many cities nationwide are dealing with. Research Objectives The application of passively su rvivable technologies to a single-fam ily home in Florida is the main purpose of this thesis. Secondary obj ectives include adapting and coupling the ideas covered in the literature review together to achi eve survivability duration of two weeks. Creating a passively survivable home, in essence, provide s for a home that can become independent from local utilities during post disaster times while still providing critical components for the occupants survival. Scope and Limitations The passive survivab ility model home will be based in Jacksonville, Florida, which was chosen due to its varied weather conditions. Cl ose to the coast, this location has hot humid summers along with cooler winters, therefor e making the model homes passively survivable technologies applicable to most of (or rather coastal) Florida. Cool climate dominated or warm climate dominated lessons can be learned from th is study, creating a useful model for the masses. The main goal of this research is the creation of a model home that can remain habitable in the event of loss of utilities. This loss of u tilities can be caused by any number of natural or

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12 human caused disasters, therefore the set of circumstances leading up to the loss of utilities will not be addressed in this paper. The costs associated with the various systems were not covered because this design guide does not cover the actua l installation, rather the application of the components. Much research and work has alr eady gone into the design of storm resilient buildings, for which the results of this resear ch should be seen as a complementary design strategy.

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13 CHAPTER 2 LITERATURE REVIEW Introduction Green building strategies have become ev er increasingly popular in the world today. Incorporation of these technologies in resident ial hom es has proven successful on a number of levels: such as being a more environmentally friendly and energy efficient end product. While this paper is not a green building construction design guide, it will however utilize green building strategies in an attempt to satisfy the problem of building passively survivable houses. The following sections of the literatur e review focus on a passive survivability checklist composed of various green building strategies that when adapted to single family residential construction will create a level of pa ssive survivability. Heating Passively heating a hom e without the use of utilities can pose a challenge during the winter. In the case of a model home in Florida, although the need for heating during the winter months is minimal, it still need s to be addressed. The following pa ssive heating design strategies employ solar energy, which is a r eadily available and fuel free, thus making the houses heating and cooling completely independent from the local utilities in the case of emergencies. When designing passive solar heating systems fo r the home, it is important that the system depends on two basic material properties: (1) the ability of materials to store and release large amounts of heat slowly into the indoor space; and (2) the ability of glazing materials like glass to transmit solar radiation and block thermal radiation (Crosbie 1998). To store the heat generated by the solar radi ation the house employs a mass storage device. The storage device must be composed of materials that have the capacity to store heat for periods of time whether it be hours or days (Crosbie 1998). Materials that are high in mass are most

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14 suited for this purpose and, in residential constr uction, masonry and concrete are the two most appropriate and abundant materials. Using these ma terials is relatively simple because in most houses they are already included in the plans to serve some other purpose. Walls and floors made of masonry and concrete are of ten found in homes, and can serve as thermal storage devices. To use this mass for storing solar energy we need to allow the solar radiati on to reach these devices in a controlled fashion. Shown in Figure 2-1, the suns path during the winter months is lower than in the summer months. Thus, simple overh angs will control the amount of sunlight per season. Proper design and placement of windows in a home is critical when heating a house passively. The main idea here is simple: glazed surfaces that allow transmittance of solar radiation should be placed to maximize the amount of sunlight allowed in the house during the winter. The suns solar radiat ion can be transmitted through the south facing windows allowing radiation to be transferred to the mass therma l storage. During the daytime the mass storage device will collect and store the ra diation in the form of heat a nd release it during the night. Simple thermodynamics state that heat flows fr om hot to cold. This simple fact is why thermal storage devices perform so well for pass ive heating. The storage device can collect or discharge the heat according to the indoor temperature. The slow rate at which heat is discharged from the storage materials creates a comfortable temperature within the indoor spaces (Crosbie 1998). Cooling Passive cooling, unlike passive solar heati ng, is based upon heat gain prevention and modulation of heat gains The objective is to lim it thermal gains, by controlling thermal radiation (Santamouris & Asimakopolous 1996). In this case during the cooling seas on the solar radiation should not be easily transmitted indoors wh ere it can create unwanted heat.

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15 Thermal storage devices are used equally as effectively for cooling as they are in heating. The only difference is that passive cooling invo lves storing coolth in stead of warmth. This coolth is transmitted to the storage device by convection from cool night air. As the day progresses and the indoor air temper ature rises the storage devices di scharge their coolth in order to receive the warmth, therefore decreasing the temperature of the ambient air. This design strategy of night cooling is usef ul in climates where there are large differences between day and night temperatures. While most of Florida may not qualify for this ni ght cooling strategy, the thermal coupling of the house to the ground will provide a cooling effect. The stable low temperature of the earth can be transferred into the concrete fl oor slab, which serves a storage device for the coolth. This coolth can then be transferred to the ambient indoor air during the day. Utilization of shading devices during the day will allow the thermal mass storage devices to store their coolth for longer time spans into the day. Shading can be acc omplished with the use of simple roof overhangs for the south orient ation of the building. These overhangs shade the windows from solar radiation during the summer m onths when the sun is higher in the sky, as can be seen in Figure 2-2. Utilizing overhangs to shade the summer sun also provides benefits for the winter heating season. Since the sun is lo wer in the sky during the winter months, solar radiation is able to penetrate the window under the overhang allowing for solar heating, as seen in Figure 2-3. Thermal shutters installed on the model hous e serve a multitude of purposes. The shades, when closed during the summer daylight hours, eliminate the sola r radiation that causes heat buildup inside a home. The main advantage of this system its usefulness during both the heating and cooling season. The operation of the system is inverted in the cooling season by exposing the

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16 mass to the sun and insulating at night as opposed to insulating the mass during the day and exposing it at night (Santamouris & Asimakopolous 1996). In essence thermal shutters offer a higher thermal resistance (R-value) for windows. Keeping the thermal shutters closed will effectively make a tighter building envelope, whic h in conjunction with the thermal mass storage devices will limit indoor temperature swings. The use of landscaping as a shading device is another element included in passive cooling. Trees placed around a building not only block solar radiation but also reduce ambient air temperature through the process of evapotra nspiration (Santamouris & Asimakopolous 1996). The use of deciduous trees on the homes south f acing wall is another e ffective way to control solar radiation. Figure 2-4 shows the differences in transmittance of sola r radiation during the winter and summer months. As can be seen, deciduous trees aid in passively heating and cooling by naturally shedding leaves with the change in seasons, therefore eff ectively controlling the amount of solar radiation allowed in the home. East and west orientations of homes are particularly vulnerable to solar radiation during the sunrise and sunset periods of the day (Figure 2-1). In order to c ontrol the solar radiation allowed in the home during these periods, minimization of size of east and west facades should be designed for. Minimizing east and west exposure, while also utilizing landscaping to shade glazed surfaces on these facades, will serve to protect the building during the early and late hours of a given day. Natural Ventilation Natural v entilation combined with the passive cooling techniques previously described will effectively make the model home a habitable envi ronment. Natural ventilation is necessary to cool the occupants of the home. It is important to remember that the design techniques addressed in this paper serve not to remove the cooling load of a home but rather as a secondary system in

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17 the case of an emergency when the active cooling system has failed. These techniques extend the tolerance limits of thermal comfort for the occupants in the indoor space (Santamouris & Asimakopolous 1996). The house should utilize an active means to co ol the interior such as a forced air conditioning system. The passive cooling technologies are a back-up system, which will serve to maintain livable conditi ons in the event of a loss of power. When a loss of power renders the active syst em inoperable, it becomes necessary to exchange warmer inside air with cooler outs ide air by passive means. Cooling the building involves exchanging cooler outside air with wa rm inside air, while people cooling can be accomplished through circulation of indoor air (M oore 1993). Natural ventilation for the model home will be carried out by the use of two types of ventilation: cross ventilation and stack effect. Between the two types of ventilation, cross ventilation is a more efficient people cooler. The ventilation process works to cool people in two ways: evaporation and convection (Moore 1993). Natural cross ventilation occurs when there are pressure differentia ls across a building. In order to utilize these differentials to the hom es ventilation advantage, operable windows on opposite walls will be designed for. Cross ventila tion design criteria include a room depth of greater than 2.5 times the ceiling height along with a maximum room depth of 5 times the ceiling height (Awbi, 2003). When sizing windows for natura l ventilation it is impor tant to know that maximum ventilation occurs with equal size in let and outlet openings (United Nations, 1990). Effective use of landscaping not only provides fo r passive cooling but can also be used to aid in natural ventilation. Formations of trees and shrubs beside the home can be used to funnel winds through window openings. In order to mainta in proper ventilation for the home, while still protecting west and east exposures tall trees will be ut ilized. Figure 2-5 shows that taller trees will allow natural breezes to pass, while still shading the house with the higher leaf cover.

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18 The design of the interior part itions also plays an important role in maximizing natural ventilation. If interior partitions are utilized in the home then placing them parallel to the direction of airflow will have the least effect on airflow (Moo re, 1993). With this design criterion in mind the model home was designed to utilize a more open floor plan. This open floor plan increases natural ventilation and also natural daylighting (dis cussed in the natural lighting section). Stack effect ventilation is the second natural cooling strategy dealing with ventilation that can be utilized in a home. The general concept deals with the difference in buoyancies between warm and cold air. Warm air tends to rise due to its buoyancy and ventila tion of this warm air through upper openings is quite advantageous. With the escape of the warmer air, cooler air is drawn inside from lower openings, effectively intr oducing cooler temperatures for interior of the building. In order to take advantage of the stack effect the model home us es operable clerestory windows at the highest point in the house. The stack flow of air will be more effective when used in conjunction with the solar gain in the cleresto ry due to the elevation of the air temperature (Awbi 2003). Coupled with the lower window cross ventilation the clerestory windows will use the stack effect to create livable conditions passively (Figure 2-6). Daylighting In the event of a loss of power hom es can utilize natural day lighting. The basic idea behind daylighting for any home is to accept diffuse sunlight from the windows, which will provide light for the interior of the hom e. Accepting diffuse and not direct sunlight is an important concept to reduce unwante d solar heat gains. In other areas that cannot access the sunlight readily, tube skyl ights can be installed. Tube skylights (Figure 2-7) can allow as much as 900 watts of light into a room on a sunny day and as

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19 much as 100-500 watts on a cloudy day (Schaeffer & Pratt 1999). These tube skylights do not allow transmittance of solar radiation, making th em more effective in avoiding heat gain. Natural daylighting is coupled with the cleres tory windows already in use with the passive heating and natural ventilation systems. The majo r advantage of using cler estory windows is the fact that they allow light deeper into a space than with window s alone (Crosbie 1998). This is especially important with an open floor plan hou se because the clerestory can effectively serve the large interior portions of the house with natural light. Avoiding excessive solar exposur e during the cooling season dire ctly ties into natural day lighting and must be addressed to avoid overheating problems. In order to provide effective thermal protection shading devices should be pla ced on the exterior of the home (Crosbie 1998). To overcome an overheating problem during the summer months, when the sun is high in the sky, overhangs will be installed on the cleresto ry windows on the south facade. These overhangs shade the windows during the cooling season when the sun is high in the sky and during the heating season will allow penetration of direct solar radiation. Interior shading of the cleres tory windows is another aspect of avoiding overheating. Due to the position of the windows in the home it is n ecessary to have interior instead of exterior shading because operation is faci litated with indoor access. For best performance the shading devices should not only block solar radiation but also provide insulati on during the day in the cooling season and at night in the heating season (C rosbie 1998). Figure 2-8 shows an example of interior thermal shades that will provide a higher thermal resistance for the clerestory windows when necessary. Photovoltaic Power Providing a secondary f orm of power is an essential element for passive survivability. Photovoltaic power generation involves collecting and storing sola r energy. Since this energy is

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20 free and renewable, photovoltaic power systems are advantageous to passive survivability. These systems can supply enough power to operate e ssential appliances dur ing utility service downtime. Figure 2-9 shows the basic components and la yout of a photovoltaic power system. The collector located on the roof se nds power downstream to the inverter. From the inverter, power can be supplied to the AC breaker box and batt ery bank. The battery bank serves as a storage device for the power. The breaker box controls the circuits, which deliver the photovoltaic power. Another critical safety component for any photovoltaic power sy stem is the circuit breaker. This device eliminates the ri sk of electric shock for anyone serv icing the power system. Rain Water Collection Present-day houses m ainly rely on city wate r and a loss of water supply to these houses can cripple their functionality. Within these hous es any normal water fixture is rendered useless unless there is a backup water supply system. To overcome this over reli ance on city water one must look elsewhere for a supply. Lo cated in Florida, one of the wettest states in the country, rainwater can provide the dependence n ecessary for passive survivability. Rainwater collection systems are relatively simple systems and are utilized all over the world. These systems in general, utilize a num ber of components (G ould & Petersen 1999): A catchment surface where the rainwater runoff is collected A storage system where the rainwater is stored until required A delivery system for transporting the water from the catchment to the storage reservoir An extraction device to take the water from the reservoir The catchment surface in a residential setting is most often the roof of the house. Utilizing the roof is advantageous because it does not require any major design criteria to function. Normally the gutters on a house catc h the runoff and direct it to downspouts that discharge to the

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21 city storm sewer, but in this case the runoff will be directed to a large cistern. Stored in the cistern the water will sit until re quired for use in the home. This collected rainwater can be used for many purposes. In developing countries some families are solely dependent on harvested rainwater, but for the purposes in a city, like Jacksonville, the stored water will be a seconda ry source of water with the city being the primary. This secondary water source, during nor mal operation times, will be mostly used for gardening and flushing toilets. Ho wever during emergency situations this collected water can be used for survivability purposes ranging from drinking water to clothes washing. Harvesting rainwater creates the independence a build ing needs during emergency situations.

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22 Figure 2-1. Suns path in summer and wint er (Naumann, Quivik, Riley, & Sesso 1979) Figure 2-2. Window over hang blocking sun radiation durin g summer months (Crosbie 1998)

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23 Figure 2-3. Window over hang allowing sun radiation during winter months (Crosbie 1998) Figure 2-4. Summer/winter tree performance (Santamouris & Asimakopolous 1996)

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24 Figure 2-5. Use of tall plants to maximi ze breeze and provide shade (Santamouris & Asimakopolous 1996) Figure 2-6. Stack effect ventilation (Moore 1993)

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25 Figure 2-7. Tube skylight (Schaeffer & Pratt, 1999) Figure 2-8. Thermal shade for clerestory windows (Moore 1993)

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26 Figure 2-9. Example PV array wiring schematic (freesunpower.com, 2008)

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27 CHAPTER 3 RESEARCH METHODOLOGY Introduction This thes is is determined to integrate passively survivable techniques into single-family home construction in Florida. Research started with the creation of a passive survivability checklist (Appendix A). This checklist served as a guide when consulting libraries for research materials. Passive design construction texts serv ed as the bulk of information for the thesis. Using the checklist as a guide and learning from the literature, the various techniques then needed to be applied to a si ngle-family home in Florida. Assumptions Having chosen Jacksonville, Fl orida, for the location of the model hom e, assumptions based on the location were made to justify passive survivability. Choosing an average family size of 4 people, when the average family size is 3.2 (2006 Census data) was done to add in a factor of safety for design criteria. The duration for wh ich a family could remain living in the model home was another critical assumption that was made. A time period of 2 weeks was chosen as the length of time a family could survive. Choosing this time period was based on a 2006 hurricane workshop after the Katrina and Rita hu rricanes. The time period of two weeks was the average utility downtime for category 3 storms. Although this paper is not exclusively about passively surviving hurri cane damage, this type of weather da mage has the highest probability of affecting local utilities thereby justifying set ting the length of surviv ability at 2 weeks. Creating a Model W ith a 2-week survivability duration, the design stages of the model home included sketching a model home. The main purpose of developing the model was to showcases the homes various passive survivability techniques. Googl e Sketch-Up was used to design a basic

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28 model home for single-family construction in Fl orida. Screen shots of the model home are referenced as figures in the re sults section. The models interrel ated strategies can serve as a design strategy for designers and builders interested incorporating passive survivability into building design.

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29 CHAPTER 4 RESULTS Heating and Cooling Applying the concepts covered in th e literature review th e model home employs passive solar heating and cooling strategies. For the model home, located in Florida, the southern face of the house will receive the most sunlight per da y and windows placed here will prove the most efficient for solar radiation uses. The model home (Figure 4-1) is orientated with the main facades of the house facing to the south and north. East and west exposures are minimized because controlling solar radiation becomes too difficult. Passively heating the hom e will be accomplished using solar radiation. The transmittance of solar radiation into the home will be allowed due to the low elevation of the sun in respect to the windows (Figure 4-2). During the winter months the deciduous trees will loose their leaves, allowing the su ns solar radiation to pass through into the home to be stored in the floors and walls. This stored heat can then be slowly released to the am bient indoor air during winter. During the summer the opposite passive solar design approach is employed. In this case heat gain prevention is the goal and this is accomplished by limiting the amount of solar radiation allowed into the home. With the sun s elevation angle much higher, roof overhangs (Figure 4-2) will block solar radiation transmitta nce to the windows. Figure 4-2 also shows that due to the suns low elevation angle during the time period of October 1st to May 1st, solar radiation is allowed into the home. The deciduous trees, now covered with leaves, will provide added protection to the low southern facing windows. Thermal shades (Figure 2-8) will be provided for all glazed surfaces of the home. Operat ion of these shades will limit the heat gains in the model home, avoiding overheating problems during the summer.

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30 Natural Ventilation Natural v entilation combined with passive cooling will provide a more habitable environment for the model home. It is important to remember that th is design strategy of combining natural ventilation with passive cooli ng will be used in emergency situations and will extend the thermal comfort zone for the habita ble indoor space. Having stated this, natural ventilation of the model home will be carried out by applying lessons learned from cross ventilation and stack effect ventilation. Figure 4-3 shows the layout of the model home with a very large central area. This area was designed to create an open layout for the mo st often occupied rooms of the house. The other rooms of the house are located on the east and west sides of the home to eliminate the direct solar gain into the main living area. The garage bedrooms, bath, and utility room could occupy either side of the home but have been located in this layout to reduce he at gain into the home. This open floor plan benefits cross ventilati on because there are no walls impeding the natural crosswinds. Operable windows, on the north and s outh side, with equal op ening size will serve as the inlet and outlet for the cross draft. The rooms on the east and west end of the home will also utilize natura l ventilation in the case of the active cooling system failure. D ouble hung windows are placed in these rooms so one-sided ventilation could be possible. Thes e double hung windows, with their lower and upper openings, will effectively allow warm air to rise out of the room while drawing in cooler air from the lower opening. The stack effect was applied to the model home by designing operabl e clerestory windows at the top of the home. These openings, due to their high position in the home, will vent warm air to the outdoors while allowing cooler outside air in from the lower window openings. Stack

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31 effect combined with cross ventilation will re move unwanted heat from the model home along with creating ventilation that will cool the occupants. Landscaping for the model home not only blocks solar radiation but will also aid in ventilation. The south elevation utilizes low vegetation around the window openings (Figure 44). This vegetation creates a cooler microclimate, which will provide cooler air for ventilation. The deciduous trees are al so located to funnel air currents into the home. The east and west side landscaping plan can be seen in Figure 4-5. Th ese two sides of the hom e utilize taller trees, which provide shade while also providi ng an unobstructed path for ventilation. Daylighting In the ev ent of a power loss the model homes natural daylighting will provide sufficient light indoors. The clerestory windows allow deep pe netration of light into the large open area of the home. The color white was chosen for the homes various materials finishes. Two prime examples of the white finish are th e roof and interior walls, which ar e utilized to reflect light into the living space. Glazed surfaces on the north en d of the home accept reflected light, aiding in the natural daylighting strategy. While the model home utilizes landscaping to shade windows from dir ect solar radiation this rejection of usable light is made up for with the acceptance of light from the clerestory overhead. In addition to the sunlight allowed th rough the clerestory a nd exterior windows the model home will also utilize tube skylights. Thes e will be installed on the exterior rooms located on the east and west side of the home, which include the bedrooms, garage, utility room, and bathroom. These special skylight s provide overhead sunlight thr ough a mirror finished aluminum pipe through the roof of the house. These tubes skylights (Figure 27) are simple roof penetrating units that allow natural light into the model home without allo wing solar radiation. These tube

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32 skylights will be installed in the rooms that do not have access to the overhead light provided by the clerestory windows. Photovoltaic Solar Power Generation In the ev ent of a power loss, daylighting design strategies work well in conjunction with the sun, but during the nighttime hours, lighting is re quired not to mention the fact that power is needed to run essential applia nces. The model home will utili ze a small photovoltaic array to supply enough power for small task li ghting and essential appliances. The array will be located on th e south roof of the model hom e. The array panels will be built into the roof, meaning they will take the place of the roofing material, creating a smooth flush roof surface (Figure 4-6). The reason for th is is to protect the array from wind damage. A smooth roof surface will not create any uplift potentia l for the panels as compared to panels tilted and mounted above the roof surface. Designing the r oof pitch to match the latitude of 30 degrees for Jacksonville will produce the highest energy efficiency for the PV array. The PV array for the model home will be a gr id-connected system. This means that the power supplied from the array during normal opera tions (grid power available) will be fed back into the city power grid. The home will have an inverter, which will convert the DC power into AC power, and the utility company will install a separate PV power meter. This additional meter runs backwards, so in essence the homeowner is billed for the power di fferential usage between the PV generated and the power usage of the home. During emergency situations, when the city power grid is down the model homes PV system will provide power for the home. The PV system running independently of the city power will be limited in its power supply. The model hom e has been designed to utilize only chosen appliances in this instance. This emergency circ uit, fitted with a breaker, can be switched on when city power fails. The breaker serves as a safety device in the even t of service work. The

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33 homes emergency circuit has batteries downs tream which are charged and ready to supply power during the nighttime. The ap pliances selected were based on what could not be provided passively from the houses various other passiv e technologies. Small light ing fixtures throughout the home will be provided power for nighttime use due to the absence of daylighting at later hours of the day. A small refrigerat or can also be connected to th e emergency circuit so essential food can be kept cool. Another appliance that wa s taken into account for the emergency circuit is the power needed to charge a ce ll phone or laptop computer, in the event of an emergency when communication technology is essential. Sizing the system included the use of the sy stem sizing estimate program obtained from freesunpower.com. The software calculated the amount of 80-100 Watt panels and battery storage size based on the following inputs: 1 4-5 cubic foot fridge operating with below normal usage 200 watts of lighting operating for 3 hours a day 1 Laptop computer operating for 2 hours a day The outputs of the software can be seen in Figure 4-7. As shown, three 80-100 watt PV panels are required with seve n 12-volt batteries operating at 105 amp hours. The wiring schematic as seen in Figure 2-9 is an example of how the PV array would be wired for the model home. Although the AC generator is not included in the model s home backup power, this figure displays a basic wiring schematic for the model home. The AC (alternating current) out breaker box as seen in the schematic will control the various emergency circuits throughout the house, and will be located in the utility room. These circuits will each have small emergency lighting fixtures that can be switched on and off via the individual break er. Included in the emergency circuit breaker panel will be a circuit for an ou tlet run in the utility room, which will service the small fridge as well as a laptop or cellular phone.

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34 Water The m odel home utilizes collected rainwater as a secondary source of water for the house. Located in Florida, one of the wettest states in the country, rainwater is abundant during most times of the year. Utilizing this rainwater allows the model home to be more independent from the local utilities. In the event of a loss of city water the occupants of the home can rely on their secondary water source, th e harvested rainwater. The catchment system for the model home is th e roof. The roof is sloped to the south and north sides of the model home which will direct runoff into the delivery system or gutters. The gutters are sloped towards the west end of the house. This slope will allow for the water to be fed into the reservoir by means of gravity. The gutters will also provide a primary point of cleansing for the water. Utilizing a self cleaning component on the downspout of the gutters (Figure 4-8) debris washed into the gutters will be separated and kept out of the storage device. The storage system for the model home consists of a large underground cistern made of cement. This is where the rainwater is stored until required by the fixtures. Th e event of overflow may seem unlikely but must be addressed nonetheless. The ta nk will be fitted with an overflow device that allows excess water to be diverted into a drip line in the garden of the home. Sizing the cistern depends on multiple factors and for the model home located in Jacksonville, these factors need to be taken into consideration. The tank w ill need a capacity of around 2,000 gallons based on the calculations give n from the Harvested Rainwater Guidelines on the Green builder website. The average size fam ily in Jacksonville, according to the U.S. census bureau is was 3.20 in 2006 so to be safe in designing the cistern size 4 people are assumed. Using 40 gallons per person per day is a generous amount according to the rainwater harvesting guidelines. Using the survivability du ration of 14 days from the methodology section,

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35 the tank is sized by multiplying the 4 people, 40-gallon/ person per day, and the 14-day duration together to conclude that a 2,200-gallon cistern is required. This cistern water will be extracted by mean s of an electric pump during normal periods when the house is using grid energy. The extracti on line will be fitted with a floating suction line (Figure 4-9), which will extract water from the upper storage capacity of the cistern, which is seen as the cleanest water in st orage. In the event of a power loss the extraction method for the rainwater is a simple hand pump. The extracted water from the cistern will be taken to a smaller holding tank in the upper loft area of the mechanical room (Figure 4-10) wh ere it will be stored. This smaller holding tank, due to its elevation in the house, will use gravit y as a means for delivering the rainwater to the fixtures, thereby becoming independent of city water pressure. Two float switches, one in the cistern and one in the upper holding tank, will activate the electric pump which moves water from the cistern to the holding tank. The electric pump will be shut off when either the upper holding tank is full or the cister n is empty. The latter event, howe ver unlikely, will be minimized with a make-up inlet of city water in the rare ca se that the cistern is dr y. This city makeup water will be controlled by another float switc h located in the underground cistern. The design of the model home has a hybrid wa ter deployment system. Collected rainwater will be used mainly for flushing of toilets and outside watering. Another tap for harvested rainwater is located in the utility room at the slop sink. In the case of a loss of city water this tap can service the slop sink for clot hes washing and other essential needs. Operation of the hand pump in the utility room will fill the upper holding tank and then the toilet, slop sink, and exterior hose bib remain opera ble due to gravity delivery.

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36 The issue of wastewater systems backing up or failing is another concern that the model home design has taken into accoun t. In the instance of waste water systems failure all operation of city connected water fixtures should be ceased. The slop sink in the utility room will now serve as the homes central water fixture (sol id waste disposal is covered in the following section). This drainage system for the slop sink is separate from all other fixtures in the house. The drainage system consists of a rock and sand bed in the yard. This system is very permeable and able to handle large amounts of wastewater. As the water r uns through the layers of the drainage bed it is also cleansed before returning to the water ta ble below. Since the system is located underground, access hatches must be insta lled to service the filter and perform other repairs. This separate drainage system give s the model home independence when wastewater service disruption occurs. Surviving in the Model Home There are many issues involved with surviving in the m odel home that cannot be addressed by specific design techniques. This sections aim is to cover these various aspects of survival. The utility room (Figure 4-11) at the east end of the house can serve a wide variety of purposes for the model home. Due to the design of the ceiling height, space was limited to store certain mechanical equipment, so the loft was added to the utility room to house the upper rainwater harvesting tank, hot water heater, and the components for the PV system. Another design strategy for this room was to pla ce it in the interior of the home so that the only openings to the outside would be a solid stor m door. This room can be utilized as a shelter during storms because there is no danger of flying debris breaking through windows. With such solid construction this serves as the houses main food storage area. Keep ing a stocked inventory of dried and canned food will provide sustenan ce during emergency situations. With the harvested rainwater tank convenien tly located above drinking wate r can be provided by means of

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37 gravity through an outlet. This outlet will have th e capability to be fitted with a water filter, which can be changed when necessary. Cooking in the event that gas utilities fail w ill be accomplished with the use of propane. Twenty-pound backup tanks with a po rtable stovetop will provide cooking needs for the family. Cooking scraps and waste that are organic can be d ecomposed in a composting pile in the yard in the case that waste disposal is unavailable. Co mposting solid waste is another issue that the model home must employ in the case that city sewer lines fail. A composting toilet is a relatively low priced option that can operate without wate r and wastewater utilit ies. A self-containing model can sit dormant until needed and the non-el ectric model installation only requires a small vent to the roof. As mentioned previously in the Water s ection, the slop sink in the utility room will service many needs of the occupants in the case of utility failures. The rainwater tap becomes the access point for water related activities. Due to its gravity fed capability and separate waste water system, this sink can operate completely i ndependently of any city utilities. The various systems and elements that are operated from th is room include rainwater access and emergency PV circuit control, as well as serving as a pla ce of shelter and food stor age. The utility room itself becomes the central hub of activity during an emergency situation.

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38 Figure 4-1. Orientation of model home Figure 4-2. Sun elevation for May 1st & October 1st

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39 Figure 4-3. Layout of model home Figure 4-4. South elev ation landscaping plan

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40 Figure 4-5. West elev ation landscaping plan Figure 4-6. In-roof installation of PV array (Deutsche Gesellschaft fu r Sonnenenergie, 2005)

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41 Figure 4-7. Output data for PV system (freesunpower.com 2008) Figure 4-8. Self-cleaning gu tter component (Gould 1999)

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42 Figure 4-9. Floating extr action filter (Gould 1999) Figure 4-10. Riser diagram of rainwater delivery system

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43 Figure 4-11. Utility room

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44 CHAPTER 5 CONCLUSION The m odel home effectively utilizes passive heating, cooling, lighti ng, and water saving technologies. These technologies coupled together have the prim ary benefit of allowing the occupants to survive in the model home during non-utility service time. Justification is best accomplished by looking at the secondary benefits of designing a passively survivable house. These benefits, which are secondary to creati on of a non-utility dependant house, deal with environmental and cost savings concerns. Many of the technologies applied to the mode l home, in nature, are green technologies. Natural ventilation and daylighting, along with pa ssive heating and coolin g, substantially reduce the amount of energy the model home needs to ope rate. This allows for a lower size of heating and cooling equipment that will be installed on the house. The duration of operation time for this equipment will also be significantly reduced due to the design strategies that prevent large indoor thermal swings. During daylight hours, the mode l home will not require much, if any, power to light the interior of the home. The effective us e of daylighting keeps lighting power demand low, again reducing the amount of power required from the grid. The rainwater harvesting system will effec tively reduce the amount of water demand for the home. With water crises emerging throughout the country, the rise of water prices is inevitable, so any step towards reducing the amount of water consumed by the household is advantageous to not only the environment but also in keeping operating costs low. According to the harvesting rain water table in the harves ting rainwater guidelines, the model homes 2500sf roof in Jacksonville, which receives on average 52 inches of rainfall per year, will have access to over 73 thousand gallons of water annually. With that astounding amount of water it is no wonder why Florida is the wettest state in the nation. The question arises as to why more houses

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45 do not employ rainwater harvesting, when such a valuable resource can be collected with minimal effort. The combination of the various passively survivable technologies led to the creation of a residential model. The ability to provide critical life support f unctions during times of utility downtime has been effectively designed and appl ied to the model home. In the event of an emergency, the loss of any number or combina tion of utilities has been accounted for when designing the various systems. The passive heating and cooli ng strategies that were designed for the model home allow it to provide the thermal conditions necessary to survive indoors, while being completely dependent from local utilities. In the event of a loss of power to the home, daylighting provides sufficient light indoors, while the small PV arra y provides necessary back up power for essential appliances. Loss of city water, while not a very common occurrence, it is a possibility in the future especially with the recent occurrence of water crises throughout the nation. The rainwater harvesting system is designed as a hybrid wa ter distribution system, which can effectively operate during times of no water ut ility service, as well as redu ce the amount of water consumed by the household. With the creation of this passively survivab le residential model the foundation for new building design criteria has been laid. In the fu ture, designers and builders can look upon this thesis as a stepping-stone to re searching and developing new tec hnologies and applications that could extend to various climates as well as building types. Recommendations for future research would be an investigation into other various green technologies that improve the pass ive survivability of single-fam ily homes. Testing the various

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46 design elements and determining their efficienci es is the next step in developing passive survivability into our built environment. Recommendations for designers and builders would be to adap t passive survivability into larger residential and commercial buildings. Integr ating the idea of passi ve survivability into building codes will provide safer and more ha bitable shelters during post disaster times.

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47 APPENDIX PASSIVE SURVIVABILITY CHEKLIST Passive Heating o Glazing orientation/sizing depending on latitude o Mass storage devices depe nding on building materials Passive Cooling o Overhang design depending on latitude o Night cooling depending on climate region Natural Ventilation o Stack effect depending on design of home o Cross ventilation depending on size/layout of home Daylighting o Glazing depending on design of home (i.e. Clerestory window, tube skylights) Rainwater Harvesting o Cistern capacity depending on number of occupants Photovoltaic Power o Array size depending on amount of power required o Array mounting angle depending on latitude

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48 LIST OF REFERENCES All-Industry Research A dvisory Council. ( 1989). Surviving the storm: building codes, compliance and the mitigation of hurricane damage. Oak Brook, Ill: All-Industry Research Advisory Council. Awbi, H. B. (1991). Ventilation of buildings. London: E & FN Spon. Awbi, H. B. (2003). Ventilation of bu ildings. London: Taylor & Francis. Black, R. J. (1993). Florida climate data. [Gainesv ille, Fla.]: University of Florida Cooperative Extension Service, Institute of F ood and Agriculture Sciences, EDIS. http://purl.fcla.edu/UF/lib/EH105. Crosbie, M. J., (Ed.) (1998). The Passive Solar Design and C onstruction Handbook. New York: John Wiley & Sons, Inc. Crowley, J. S., & Zimmerman, L. Z. (1984). Pr actical passive solar design: a guide to homebuilding and land development. An Energy learning systems book. New York: McGraw-Hill. Deutsche Gesellschaft fu r Sonnenenergie. (2005). Planning and installing solar thermal systems: a guide for installers, architects, and e ngineers. London: James & James/Earthscan. Energy Efficiency and Renewa ble Energy Clearinghouse (U.S.). (1994). Solar heating and you. Washington, D.C.?: Energy Efficiency and Renewable Energy Clearinghouse. Energy Efficiency and Renewa ble Energy Clearinghouse (U.S.). (1996). Solar water heating. [Washington, D.C.?]: Energy Efficiency and Renewable Energy Clearinghouse. Galloway, T. R. (2004). Solar house: a guide for th e solar designer. Oxford: Architectural Press. Gould, J., & Nissen-Petersen, E. (1999). Rainwa ter catchment systems for domestic supply: design, construction and implementation. London: Intermediate Technology Publications. Hestnes, A. G., Hastings, R., & Saxhof, B. (1997 ). Solar energy houses: strategies, technologies, examples. London: James & James. Kibert, C. J. (2008). Sustaina ble construction: green buildi ng design and delivery. Wiley book on sustainable design. Hoboken, N.J.: John Wiley & Sons. Littlefair, P. J. (2000). Environmental site layout planning: solar access, microclimate and passive cooling in urban areas London: BRE Publications. Moore, F. (1993). Environmental control sy stems: heating, cooling, lighting. New York: McGraw-Hill.

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49 Naumann, H., Quivik, F., Riley, T., & Sesso, J. (1979). Natural cooling for homes: low-energy concepts. Butte, Mont: National Ce nter for Appropriate Technology. Santamouris, M., & Asimakopoulos, D. (1996). Passive cooling of buildings. London: James & James. Schaeffer, J., & Pratt, D. (1999). The Real Goods solar living sourcebook: the complete guide to renewable energy technologies and sustainable living. Ukiah, Calif: Real Goods Trading Corp. Skistad, Hkon. Displacement Ventilation. New York: John Wiley & Sons, 1994. United Nations Centre for Human Settlements. (1990). National design handbook prototype on passive solar heating and natura l cooling of buildings. Nairobi: United Nations Centre for Human Settlements (Habitat). United Nations Environment Programme. (1983). Rain and stormwater harvesting in rural areas: a report. Dublin: Published for the United Nations Environment Programme by Tycooly International Pub. Van Dresser, P. (1995). Passive solar house ba sics. Santa Fe, N.M.: Ancient City Press. Williams, J. M., Duedall, I. W., & Doehring, F. (1997). Florida hurricanes and tropical storms. Gainesville: University Press of Florida. Wilson, Alex. Passive Survivability: A New Design Criterion for Buildings. Environmental Building News. 2006. Accessed on January 21, 2008 from http://www.buildinggreen.com/aut h/article.cfm ?fileName=150501a.xml

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BIOGRAPHICAL SKETCH Andrew Joseph Mejia was born in 1985 to becom e the 5th member of the Mejia family. His hometown of Oak Park, Illinois is where he attended Fenwick High School. Purdue University in West Lafayette, Indiana is where Andrew r eceived his Bachelors degree in Building Construction Management in the spring of 2007. Fa ll of 2007 he started graduate school at The University of Florida. Andrew received his Masters of Science in Construction Management from the M.E. Rinker, Sr. School of Buildi ng Construction in the summer of 2008. He has moved back to Chicago to begin work in the construction industry.