Applying Building Science to Refrigerated Buildings and Cold Storage Facilities What Is a Building?
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Applying Building Science to Refrigerated Buildings and Cold Storage Facilities What is a Building? 2 A Building is an Environmental Separator 3 Defrost Time Lapse What is Building Science? • Not a mature discipline • Most building scientists have a civil engineering, mechanical engineering or architecture background • If offered, universities don’t quite know what to do with it –is it the architectural side of engineering? Is it the technical side of architecture? • Includes a unique mix of physics, material science, meteorology, construction technology, physiology, and engineering analysis in the physical sciences (chemistry, thermodynamics, fluid mechanics, heat transfer, psychrometrics) Thermodynamics • Zeroth Law – Equal Systems • First Law – Conservation of Energy • Second Law –Entropy • Third Law – Absolute Zero The Second Law of Thermodynamics • “In an isolated system, a process can occur only if it increases the total entropy of the system.” • Huh? The 2nd Law of Thermodynamics in Layman’s Terms • Heat goes from warm to cold • Moisture goes from warm to cold • Moisture goes from more to less • Air goes from high to low Key Psychrometric Concepts • At any given temperature, there is a maximum amount of water vapor that the air can hold (i.e. saturated air) • The warmer the air, the more moisture the air can hold (exponential function) • Relative humidity will increase when air is cooled (at constant dewpoint) • Condensation will occur on any surface that is colder than the dewpoint temperature of the air around it Performance Requirements for the Building Enclosure • Control heat flow • Control airflow • Control water liquid penetration • Control water vapor flow • Control light and solar radiation • Control noise • Control fire • Provide strength and rigidity • Be durable • Be constructable, maintainable, and repairable • Be aesthetically pleasing • Be economical • Be sustainable Enclosure Control Layers • Water Control Layer (WRB) • Air Control Layer (Air Barrier) • Vapor Control Layer (Vapor Barrier/Retarder) • Thermal Control Layer (Insulation) Image courtesy of Building Science Corp. Image courtesy of Building Science Corp. Insulated Metal Panels Images courtesy of Building Science Corp. Compact Roof Assembly Image courtesy of Building Science Corp. Insulated Metal Panel Roof Image courtesy of Building Science Corp. It’s All About the Joints • Water control continuity • Air control continuity • Vapor control continuity • Thermal control continuity Wall Panel Joint Image courtesy of Building Science Corp. Wall Panel Mounting Clip Image courtesy of Building Science Corp. Roof Panel Joint Image courtesy of Building Science Corp. Roof Panel Mounting Clip Image courtesy of Building Science Corp. The Perfect Slab, Err…. The More Perfect Slab Summary • Refrigerated buildings and cold storage facilities are a challenge to design and construct • The enormous energy potential (more to less, high to low) across the enclosure needs to be accounted for • Properly applied building science principles translates to durable and energy efficient facilities • Building science is all about continuity of enclosure control layers • You have to be attentive to and concerned with accuracy and detail .