THE GREENHOUSE EFFECT a short, but important, topic for passive heating and for climate change http://www.solcomhouse.com/globalwarming.htm Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 1 The Greenhouse Effect Is the physical basis for virtually all passive and active solar thermal systems (a system that intentionally converts radiation to heat) opaque object Improving the performance of a solar thermal system means increasing the effectiveness of the greenhouse effect a PV system is a solar-electrical system; not a solar thermal system Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 2 1
A Building-Scale Greenhouse Effect Involves the Following Steps Shortwave (solar) radiation is emitted by the sun, easily passes through space, and readily passes through the Earth s atmosphere The shortwave radiation also passes through glazing (because transparency is a basic property of glass and a fundamental reason why it is used in buildings) The shortwave radiation is absorbed by a material within the building Absorption of shortwave radiation heats the material Then >>> The temperature of the material rises The material emits longwave (infrared) radiation to its surroundings (and also convects, and perhaps conducts, heat) Longwave radiation is generally reflected by glazing, redirecting this energy back into the room The room temperature rises (due to convection from warmed objects and the trapping of longwave radiation emitted by such objects) Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 3 The Greenhouse Effect works in cars and works in collectors the less mass the greater the heating Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 4 2
Glazing as Connector/Barrier transmissivity UV IR (longwave) high visible transmittance light barrier filter connector low IR transmittance wavelength effect of angle of incidence on transmissivity http://steve.cooleysekula.net// Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 5 The Greenhouse Effect in a Building shortwave absorbed longwave glazing is a connector for shortwave radiation and a barrier for longwave www.learn.londonmet.ac.uk/ Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 6 3
Architecturally Inducing the Greenhouse Effect overheating controls greenhousesforall.yolasite.com www.infobarrel.com these examples have no underheating controls Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 7 Designing for the Greenhouse Effect greenhouse effect in design: direct gain solar and living machine at Islandwood campus Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 8 4
The Greenhouse Effect and a Thermal Collector www.volker-quaschning.de/ remove the glass cover sheet and solar radiation reaching the collector plate increases; but convection loss and outgoing heat (IR) radiation both Increase by a greater magnitude resulting in much lower net available heat Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 9 The Greenhouse Effect and Earth when incoming and outgoing are in balance the Earth s temperature is stable; if outgoing (longwave) is restricted more than incoming (shortwave), then climate changes NASA Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 10 5
Effects of the Greenhouse Effect ecology.com/features/vanishing-artic-ice-cap/images/2007-artic-ice-cap.jpg Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 11 Greenhouse Gasses Drive The Global Greenhouse Effect iter.rma.ac.be/en/img/ CO2-concenNEW_EN.jpg www.answersingenesis.org/assets/images/ articleimages/2006/09/global-warming-2.jpg Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 12 6
Greenhouse Gasses https://iasmania.com/greenhouse-effect-greenhouse-gases/ CO2 is not the only concern Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 13 Greenhouse Gasses http://climatechange.cityofchicago.org/ www.epa.gov/ Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 14 7
Operations Matter; but so Do Materials Selections see source credits on slide Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 15 Environmental Impacts of Materials www.steelconstruction.info/life_cycle_assessment_and_embodied_carbon Ball State Architecture ENVIRONMENTAL SYSTEMS 1 Grondzik 16 8