HEATING, COOLING, LIGHTING - Healthcare Architecture

viiiâ ‡ â 1812.19365Introductionâ 366Lightâ 367Reflectance/Transmittanceâ 370Colorâ 371Visionâ 374Perceptionâ 375Performance of a Visual Taskâ 379Characteristics of the Visual Taskâ 379Illumination Levelâ 381Brightness Ratiosâ 382Glareâ 384Equivalent Spherical Illuminationâ 387Activity Needsâ 389Biological Needsâ 392Light and Healthâ 394The Poetry of Lightâ 395Rules for Lighting Designâ 395Career Possibilitiesâ 396Conclusionâ 397Key Ideas of Chapter 12â 1913.2013.2114ELECTRIC tory of Daylightingâ 400Why Daylighting?â 403The Nature of Daylightâ 405Conceptual Modelâ 407Illumination and the Daylight Factorâ 409Light without Heat?â 410Cool Daylightâ 411Goals of Daylightingâ 412Basic Daylighting Strategiesâ 413Basic Window Strategiesâ 416Advanced Window Strategiesâ 419Window Glazing Materialsâ 424Top Lightingâ 427Skylight Strategiesâ 427Clerestories, Monitors, and LightScoopsâ 432Special Daylighting Techniquesâ 437Translucent Walls and Roofsâ 442Electric Lighting as a Supplement toDaylightingâ 444Physical Modelingâ 445Guidelines for Daylightingâ 449Conclusionâ 450Key Ideas of Chapter 13â 45014.2014.21History of Light Sourcesâ 454Light Sourcesâ 455Incandescent and Halogen Lampsâ 457Discharge Lampsâ 459Fluorescent Lampsâ 460High Intensity Discharge Lamps (Mercury,Metal Halide, and High PressureSodium)â 462Solid State Lightingâ 464Comparison of the Major LightingSourcesâ 466Luminairesâ 467Lenses, Diffusers, and Bafflesâ 468Lighting Systemsâ 470Remote-Source Lighting Systemsâ 472Visualizing Light Distributionâ 473Architectural Lightingâ 476Outdoor Lightingâ 478Emergency Lightingâ 479Controlsâ 480Maintenanceâ 480Rules for Energy-Efficient Electric LightingDesignâ 481Laws and Standardsâ 481Conclusionâ 482Key Ideas of Chapter 14â 48215THE THERMAL ENVELOPE: KEEPING WARMAND STAYING 15.1215.1315.1415.1515.16453483Backgroundâ 484Heat Lossâ 485Heat Gainâ 487Solar Reflectivity (Albedo)â 489Compactness, Exposed Area, and ThermalPlanningâ 490Insulation Materialsâ 493The Thermal Envelopeâ 498Heat Bridgesâ 505Windowsâ 508Movable Insulationâ 512Insulating Effect From Thermal Massâ 513Earth Shelteringâ 515Infiltration and Ventilationâ 519Moisture Controlâ 521Radonâ 524Appliancesâ 525

CONTENTSâ ‡ â ‡ ix18RECOMMENDED LOW ENERGY CASE STUDIES15.17 Conclusionâ 526Key Ideas of Chapter 15â 52616MECHANICAL EQUIPMENT FOR HEATINGAND .2116.2216.23Introductionâ 578Traditional Tropical Architectureâ 578The Tropical Climateâ 583The Solar Geometry of the Tropicsâ 583Shading in Tropical Climatesâ 587Daylighting in the Tropicsâ 589Passive Coolingâ 589Air-Conditioned Buildings in theTropicsâ 59017.9 Conclusionâ 593Key Ideas of Chapter 17â 59418.1 Introductionâ 59618.2 Case Studiesâ 59619CHECKLIST FOR DESIGNING INTEGRATEDIntroductionâ 530Heatingâ 530Thermal Zonesâ 532Heating Systemsâ 532Electric Heatingâ 534Hot-Water (Hydronic) Heatingâ 535Hot-Air Systemsâ 537Coolingâ 540Refrigeration Cyclesâ 541Heat Pumpsâ 542Geo-Exchangeâ 543Cooling Systemsâ 545Air-Conditioning for SmallBuildingsâ 548Air-Conditioning for Large MultistoryBuildingsâ 552Design Guidelines for MechanicalSystemsâ 562Air Supply (Ducts and Diffusers)â 563Ventilationâ 566Energy-Efficient VentilationSystemsâ 568Air Filtration and Odor Removalâ 570Special Systemsâ 570Integrated and Exposed MechanicalEquipmentâ 572Low Energy Heating and Coolingâ 573Conclusionâ 573Key Ideas of Chapter 16â 57417TROPICAL TAINABLE 19.1119.1219.1319.1419.15577595599Introductionâ 600Site Selectionâ 600Formâ 600Planâ 600Windowsâ 600Daylightingâ 601Shadingâ 601Colorâ 601Thermal Envelopeâ 602Thermal Massâ 602Glazingâ 602Air Barrierâ 603Passive Systemsâ 603Electric Lightingâ 603Mechanical Equipmentâ 603APPENDIXAHORIZONTAL SUN-PATH DIAGRAMS605APPENDIXBVERTICAL SUN-PATH DIAGRAMS617APPENDIXCSOLAR ALTITUDE AND AZIMUTH ANGLES629APPENDIXDMETHODS FOR ESTIMATING THE HEIGHT OF TREES,BUILDINGS, ETC.D.1â Proportional-Shadow Methodâ 635D.2â Similar-Triangle Methodâ 635D.3â 45 Right-Triangle Methodâ 636D.4â Trigonometric Methodâ 636D.5â Tools for Measuring Vertical Anglesâ 636635

xâ ‡ â ‡CONTENTSAPPENDIXESUNDIALSAPPENDIXFSUN-PATH MODELS639649F.1â Introductionâ 649F.2â Directions for Constructing a Sun-PathModelâ 649APPENDIXGTHE WATER TABLE FOR VENTILATION STUDIES659G.1â Introductionâ 659G.2â Construction of a Water Tableâ 659APPENDIXHSITE EVALUATION TOOLSH.1H.2H.3H.4H.5661Introductionâ 661The Solar Pathfinderâ 661The SunEyeâ 661The Sun Locatorâ 663Do-It-Yourself Solar Site Evaluatorâ 663APPENDIXIHELIODONSI.1â Introductionâ 669I.2â The Sun Simulator Heliodonâ 669I.3â The Sun Emulator Heliodonâ 669I.4â The Tabletop Heliodonâ 670I.5â The Bowling Ball Heliodonâ 673APPENDIXJTABLES OF R-VALUES675APPENDIXKRESOURCES679K.1â Booksâ 679K.2â Journalsâ 679K.3â Videosâ 679K.4â Organizationsâ 680K.5â Web-Based Resourcesâ 681APPENDIXLCONVERSION FACTORS BETWEEN THEINCH-POUND (I-P) SYSTEM AND THEINTERNATIONAL SYSTEM OF UNITS (SI)BIBLIOGRAPHYâ 687INDEXâ 693669683

FOREWORD TO THE FOURTH EDITIONThe compelling words written by James Marston Fitchin 1991 in the Foreword to the first edition (which follows) are still valid, but the stakes are now much higher.Because the fate of the planet is at stake, it is no longerjust a question of following a particular architectural ordesign philosophy. Buildings consume about half theenergy produced in the United States and around theworld. Today, more than 50 percent of the world’s population lives in cities, a figure that is likely to rise to 60percent over the next two decades. It is clear that timingis critical: with 900 billion ft2 (80 billion m2) of urbanenvironment projected to be built and rebuilt in the nexttwenty years (an area equal to three times the total building stock of the United States), we are presented with anextraordinary window of opportunity to meet presentand looming threats. Our best chance of doing so is toensure that the architecture, planning, and developmentcommunity, the primary agents shaping the built environment through design and construction, have access tothe knowledge and tools necessary for the transition to adecarbonized, sustainable, and adaptive world.Professor Lechner’s book describes how to achieve thistransition in the built environment. The book illustratesthe many sustainable strategies available to designers andprovides the information needed during the early phasesof the design process, when a building’s energy consumption patterns are defined. By using the strategies presentedin this book, much of the energy consumed to heat, light,and cool buildings can be dramatically reduced.Professor Lechner’s book is also an important resourcefor those architects who are concerned about the aesthetic aspects of sustainability. He convincingly explainsand demonstrates how lessons learned from vernacular architecture can be combined with the best of modern ideas to create low-impact yet beautifully designedhumane architecture. Since carbon neutral buildings canbe fully powered by renewable resources, a future of lowimpact buildings is not only necessary but also elegantlyachievable.EDWARD MAZRIA, AIAxi

FOREWORD TO THE FIRST EDITIONProfessor Lechner’s book differs from most of its predecessors in several important respects: (1) he deals withthe heating, cooling, and lighting of buildings, not as discrete and isolated problems, but in the holistic sense ofbeing integral parts of the larger task of environmentalmanipulation; (2) he deals with the subjects not merelyfrom the engineer’s limited commitment to mechanical and economic efficiency but from the much broaderviewpoint of human comfort and physical and psychicwell being; (3) he deals with these problems in relationto the central paradox of architecture—how to provide astable, predetermined internal environment in an external  environment that is in constant flux across time andspace; and finally, (4) he approaches all aspects of thiscomplex subject from a truly cultural—as opposed to anarrowly technological—perspective.This attitude toward contemporary technology is by nomeans hostile. On the contrary, Professor Lechner handlesit competently and comprehensively. But he never losessight of the fact that the task of providing a truly satisfactory enclosure for human activity is that one must viewthe building as a whole. He points out, quite correctly, thatuntil the last century or so, the manipulation of environmental factors was, of necessity, an architectural problem.It was the building itself—and only incidentally any meager mechanical equipment that the period happened toafford—that provided habitable space. To illustrate thispoint, he makes continuous and illuminating analysis toboth high-style and vernacular traditions, to show howsagaciously the problems of climate control were tackledby earlier, prescientific, premechanized societies.This is no easy-to-read copybook for those designersseeking shortcuts to glitzy postmodern architecture. Onthe contrary, it is a closely reasoned, carefully constructedguide for architects (young and old) who are seeking anescape route from the energy-wasteful, socially destructive cul-de-sac into which the practices of the past severaldecades have led us. Nor is it a Luddite critique of moderntechnology; to the contrary, it is a wise and civilized explication of how we must employ technical and scientificknowledge if we in the architectural field are to do our bittoward avoiding environmental disaster.JAMES MARSTON FITCHHon. AIA, Hon. FRIBAIn memory of James Marston Fitch, architect,historian, professor, preservationist, andarchitectural theorist, 1909–2000.xiii

PREFACEIn this new edition the goal of previous editions remains:to provide the appropriate knowledge at the level of complexity needed at the schematic design stage. In the yearssince the first edition was published, we have movedfrom a shortage of information to a flood because of theInternet. This book will aid the designer because it presents the information in a concise, logical, and accessiblearrangement and at a useful level.Since heating, cooling, and lighting are accomplishedby adding energy to or removing it from a building, andsince the consumption of energy is causing global warming, it is vital for architects to design low energy, sustainable buildings. Although sustainability deals with manyissues, the energy issues are the most critical. Thus, anadditional goal of this book is to provide architects withthe skills and knowledge needed to create low energy andlow carbon-emission buildings.In addition to improving and updating every chapter,three new chapters have been added. Chapter 17 on tropical architecture was added because a large portion of theworld’s population lives in the tropical zone and becausemany architects trained in designing buildings in temperate climates end up designing buildings in the tropics.Case studies, formerly in Chapter 17, are now in Chapter18. Because of the extensive information available on theWeb, only a brief description is given of a personal selection of buildings.Chapter 19, the third new chapter, presents a checklistto help in the design of low energy, sustainable buildings.The checklist guides the designer through the decisionmaking process so that important options are consideredat the appropriate time.This book focuses on the schematic design stage,where the key decisions are made. The graph below pointsout how the earliest decisions have the greatest impacton a project. A building’s cost and environmental impactare established mainly at the schematic design stage. Themost basic decisions of size, orientation, and form oftenhave the greatest impact on the resources required during both construction and operation. Thus, designs forsustainable buildings are achieved primarily by the earliest decisions in the design process rather than by add-onsand engineering decisions made after the architecturaldesign of the building has been  essentially completed.The information in this book is presented to supportthe three-tier approach to sustainable design of the heating, cooling, and lighting of buildings. The first tier isload avoidance. Here the need for heating, cooling, andlighting is minimized by the design of the building itself.The second tier consists of using natural energies throughmethods such as passive solar, passive cooling, naturalventilation, and daylighting. This tier is also accomplishedmainly by the design of the building itself. The third andlast tier uses mechanical and electrical equipment to satisfy the needs not provided for by the first two tiers.With the knowledge and information presented in thisbook, the first two tiers can provide most of the thermal andlighting requirements of a building. As a consequence, themechanical and electrical equipment of the third tier willbe substantially smaller and will use much less energy thanis typical now, thereby resulting in more sustainable buildings. Since tiers one and two are the domain of the architect,the role of the engineer at the third tier is to provide only theheating, cooling, and lighting that the architect could not.xv

ACKNOWLEDGMENTSFor the fourth edition, I would like to thank especially JohnMarusich for his excellent work on the new and revised drawings. Since this book is built on the previous three editions,I also want to thank again all of the people who helped mewrite those earlier editions. The typing and proofreading forthe fourth edition were done by my son, Walden Lechner.And again, I want to thank my wife, Prof. Judith Lechner,whose help, support, and love are invaluable to me.NORBERT LECHNERProf. Emeritus and ArchitectAuburn Universityxvii

1C H A P T E RHEATING, COOLING,AND LIGHTING ASFORM-GIVERS INARCHITECTURETwo essential qualities of architecture [commodity and delight], handed downfrom Vitruvius, can be attained more fully when they are seen as continuous,rather than separated, virtues. . . In general, however, this creative melding of qualities [commodity and delight]is most likely to occur when the architect is not preoccupied eitherwith form-making or with problem-solving, but can view theexperience of the building as an integrated whole. . . .John Morris Dixon,Editor of Progressive Architecture, 1990All design projects should engage the environment in a way that dramaticallyreduces or eliminates the need for fossil fuel.The 2010 Imperative,Edward Mazria, AIA,Founder of Architecture 20301

2⠇⠇ Heating, Cooling, and Lighting as Form-Givers in Architecture1.1 INTRODUCTIONArchitecture has been called journalism in stone, since it reflects the culture, climate, and resources of the timeand place. During the Renaissance,for example, the main influence wasthe rediscovery of the classical world.What is the agent of change today?The story that is now shaping thefuture of architecture is sustainability.There are few people left today who arenot in favor of creating a sustainableworld or who would claim that weare living in a sustainable world. Sincebuilding impacts the environmentmore than any other human activity,architects have both the responsibilityand the opportunity to lead humankind to a sustainable future.Sustainable architecture can beachieved by using “the best of theold and the best of the new.” A newarchitecture is being created by usingmodern science, technology, andideas of aesthetics combined withtraditional ideas that responded tohuman needs, regionalism, and climate. Such  architecture will be morevaried than contemporary architecture, which gives no clue to where abuilding is located. Much contemporary architecture looks the same inNew York, Paris, New Delhi, or Tokyo.Furthermore, this de facto “international” architecture is equally inappropriate wherever it is built since it isnot sustainable for any climate.Sustainability covers many issues,but none is as important as energyconsumption. More than any otherfactor, the energy consumption ofbuildings is destroying the planet aswe know it. Buildings use about 48percent of all the energy consumed,with 40 percent for their operationand 8 percent for their construction(Fig. 1.1a). This energy is mostlyderived from fossil sources that produce the carbon dioxide that is themain cause of global warming. Wemust replace these polluting sourceswith clean, renewable energy sourcessuch as wind, solar energy, and biomass, or we must increase the efficiency of our building stock so thatINDUSTRIAL25%BUILDINGS48%TRANSPORTATION27%U.S. ENERGY CONSUMPTIONFigure 1.1a Buildings are the main causeof global warming because they use about48 percent of all energy. Of that 48 percent,about 40 percent is for operating the buildings (heating, cooling, lighting, computers,etc.) and about 8 percent is for their construction (creating materials, transportation, anderection). (Courtesy of Architecture 2030.)it uses less energy. Of course, weneed to do both, but decreasing theenergy consumption of buildingsis both quicker and less expensive.Furthermore, the design of energyresponsive buildings will yield a newaesthetic that can replace both theblandness of most modern buildingsand the inappropriate copying of previous styles.Is it really possible for architecture to seriously address the problem of global warming? The answeris an unambiguous yes, both becauseFigure 1.1b The good news is that buildingsdo not have to use climate-changing fossilfuels. Over the years, we have learned howto design buildings so energy efficient thatwe can now build zero-energy buildings. Thesmall amount of energy that they still needcan be supplied by renewable sources such asphotovoltaics on the roof.present buildings are so wasteful ofenergy and because we know how todesign and construct buildings thatuse 80 percent less energy than thestandard new building. Presently,there are architects around the worlddesigning “zero-energy buildings,”which are designed to use as littleenergy as possible, with the smallremaining load being met mostly byon-site renewable energy such as photovoltaics (Fig. 1.1b). We have theknow-how (see Sidebox 1.1); all weneed is the will.SIDEBOX 1.1Characteristics of a Zero-Energy House Correct orientationForm as compact as appropriate for the climate and functionExtensive use of white or very light colored surfacesSuperinsulated walls, roof, and floorAirtight construction with a heat recovery unit for ventilationHigh-performance, properly oriented windowsWindows fully shaded in summerPassive solar space heatingActive solar domestic hot waterHigh-efficiency appliancesHigh-efficiency electric lightingHigh-efficiency heating and cooling equipment (e.g., earth-coupledheat pump) Photovoltaics on roof that produce the small amount of electricitystill needed

1.2 Indigenous and V

10.3 Passive Cooling Systems 292 10.4 Comfort Ventilation versus Night-Flush Cooling 293 10.5 Basic Principles of Airflow 293 10.6 Airflow through Buildings 297 10.7 Example of Ventilation Design 306 10.8 Comfort Ventilation 307 10.9 Night-Flush Cooling 309 10.10 Double-Skin Facades and Operable Roofs 312 10.11 Radiant Cooling 313