PASSIVE SOLAR ARCHITECTURE: BASICS

J. K. NayakEnergy Systems EngineeringIIT, Powai, Mumbai 400 076

PASSIVE SOLAR ARCHITECTURE

INTRODUCTIONEXAMPLES: IMPORTANCE & USEFULNESSPASSIVE FEATURESSUMMARY AND CONCLUSIONS

Introduction

PSA : an ancient conceptModern science has provided quantitative supportLarge potential for energy conservationCan lead to a thermally comfortable indoor environment

Introduction

DEFINITIONCollection, storage, distribution and control of energy flow by natural processes of heat and mass transfer

WORKING DEFINITIONUse natural energy (sun, wind, etc.) to conserve conventional energy for achieving thermal comfortThermal comfort refers to comfortable indoor conditions (temperature, humidity, air movement)

LEDeG Trainees’ Hostel, Leh

Cold and Sunny Direct gain; Trombe wall

Solar access and daylightingdesign

Himurja office building, Shimla

COLD CLIMATEDirect gain⌧Windows

⌧Solarium⌧Air heaters⌧Solar chimney⌧Light shelves

Himachal Pradesh State Co-operative Bank, Shimla

Modified Trombe wall

Double glazed windows

Sunspaces

Air-lock lobby

Solar air heater (Roof)

Section of the building showing modified Trombe wall

Roof collector

MLA hostel,Shimla•Direct gain•Overhang•Insulation•Trombe walland sunspaces

Solar cooker Solar water heater

Residence of Sudha and Atam Kumar, New Delhi

Composite Climate

Solar exposure

Wall and roof insulation

Wind tower with evaporative coolingWall and roof surfaces: reflective

TERI Retreat, Gurgaon

Earth air tunnelSolar chimneyDirect gainInsulation

PV: solar roof

PV-Gasifierhybrid system

Earth-air tunnel System: passive space conditioning

Water and waste management system

American Institute of Indian Studies, Gurgaon

Examples: MANILA

WARM & HUMIDLight shelvesPergolasDaylightingComputer controlled energy management system

Estimated annual energy consumption approx. 1/3 rd of a conventional building

EXAMPLES: OKINAWA

WARM AND HUMID CLIMATE

Earth on roofPergolasShadingCross ventilationNight flushing

CIVIC CENTER IN JAPAN SHOWING CONCERN FOR PUBLIC WELFARE

DESERT CLIMATEWind tower with evaporative coolingEarth bermingShadingMassive structures

Examples: JODHPUR

Examples: NEGEV

ARID CLIMATEPARTIAL SUNKEARTH-BERMING (U=0.19 W/m2-K)ROOF INSULATION (U=0.28 W/m2-K)SHADINGCROSS-VENTILATION

Earth Berming

BRAMPTON (NORTH-WEST OF TORONTO)

•CLIMATE: LONG COLD WINTER, SHORT BUT WARM AND HUMID SUMMER

•KEY FEATURES: Sunspace ,superinsulation,High-performanceWindows, HVAC,Energy efficientDevices.

EXAMPLE

JAPANESE WISH HOUSE: IWAKI (NORTH OF TOKYO)

CLIMATE: MILD WINTERHOT AND HUMID IN SUMMERKEY FEATURES:Photovoltaic-thermal hybrid collectorPCM storageInsulationDehumidification with lithium bromide

COMPARISON OF ANNUAL LOAD (kWh/house)

MODERATE CLIMATE

SunspaceRoof-integrated systemsCross ventilationInsulation

Examples: OSHIMA

TORRENT RESEARCH CENTRE, AHMEDABADHOT & DRY CLIMATEBUILDING:Passive down-draft evaporative cooling

(PDEC) systemInsulatedCavity wallsNatural light and ventilationDust reduction mechanisms

PASSIVE DOWNDRAFT EVAPORATIVE COOLING SYSTEM

A system of inlet and outlet shafts

Locations, sizes and heights : generate required air movement

A fine spray of water cools the air at entry

6-9 air change rates per hour observed

Strategy:Hot season: evaporative

coolingMonsoon: cooling off, induce

ventilation by fansWinter:ventilation minimised

(inlets closed by shutters)

GERMAN ZERO-HEATING-ENERGY HOUSEBERLIN SATELLITE TOWN OF SPANDAU

Key features: super glazing, active solar collectors, storage, heat recovery, energy efficient devices

PASSIVE FEATURES

DIRECT GAIN

PASSIVE FEATURES

TROMBE WALL

PASSIVE FEATURES

SOLAR CHIMNEY

PASSIVE FEATURES

SUN SPACE

PASSIVE FEATURES

EARTH-BERMING

PASSIVE FEATURES

WIND TOWEREVAPORATIVE COOLING

WIND TOWEREVAPORATIVE COOLING

EARTH AIR TUNNEL

PASSIVE FEATURES

PASSIVE FEATURES

ROOF GARDEN

OTHER PASSIVE FEATURES

Shading devicesDesiccant coolingRoof pondTranswallRoof radiation trapIsolated gain systemsCourtyards (traditional architecture)etc.

DAYLIGHTING

Vision is by far the most developed of all our senses; Light has been the main pre-requisite for sensing thingsDaylight: coolest and efficient source of light

Cfl less efficient by about 20% to 40%Heating effect of daylighting is about 1 w per lumen; It is much less than that of artificial lighting

Various components for admitting daylightingshown in next few slides

DAYLIGHTING

EXAMPLES OF SPA : MINNEAPOLIS

DAYLIGHTING COMPONENTS

CLERESTORY

DAYLIGHTING COMPONENTS

LIGHT SHELF

DAYLIGHTING COMPONENTS

ATRIUM

SIMPLE TECHNIQUEScan be easily incorporated in the building without much additional cost. refer to design considerations involving :

• site conditions : • landform• vegetation•waterbodies• street width and orientation•open spaces and built form

•building orientation•planform

SIMPLE TECHNIQUESbuilding envelope⌧roof type: rcc, rcc with insulation, etc.⌧wall type: brick, stone, accb⌧external colour and texture:

smooth and light colour: reflects morerough textured surface: self-shading

larger surface area for re-radiationwhite or lighter shades: higher emissivity

⌧fenestration (openings)

NEW CHALLENGES

MaterialsTransparent insulationAdvanced glazings

NEW CHALLENGES

SystemsBuildings integrated with photovoltaic arraysBuildings integrated with solar collectorsBuildings integrated with active systemse.g.⌧Domestic hot water systems⌧Solar cookers

Buildings integratedWith photovoltaic Arrays

SIMULATION

To find out if the design can achieve the expected requirementsResults can be quantified

temperatureloadenergy savings

. Relative comparison of design alternatives

CONCLUSIONS

Introduction to passive solar architectureChallenges facing architects in view of new technologyImportance of simulation studies to integrate design with passive solar architecture

REMARKSNecessary to consider building as a system

Focus on total energy use (not only heating and/or cooling)

Integrate different technologiesEnergy-conservation (insulation, super windows)Passive solarActive solar

Develop whole building concept

REMARKS

Designing new, innovative building: requires multi-disciplinary design team

Energy aspects be considered at the early stageArchitects and engineers work together

Simulation: desirableConstruction practicesUser behaviour

THANK YOU