Thermodynamics Simplified Heat Flows from Warm to Cold

Originally published by the following source: Applied Building Technology GroupAugust 15, 2018
by Timothy Ahrenholz with contributions by Kirk Grundahl, P.E., Larry Wainright and Sean Shields

  

Designing a resilient building envelope can seem intimidating, especially with all the building and energy code requirements. And while there is no getting around the complexity of the interactions between a building’s interior, its walls, and the surrounding environment, things make more sense when you take the time to look at the fundamental physics at work. The second law of thermodynamics, which can be simplified to concepts like moisture flow is from warm to cold, also states that the a closed system like a building will try to move toward equilibrium. Hence the need for continuous insulation, which slows this movement and makes buildings comfortable.   This knowledge allows us to craft effective building science and building envelope solutions to manage this behavior. Many of these solutions are described in detail at continuousinsulation.org, whether you are designing commercial walls or residential walls.

In this video, in a series we are featuring, Joe Lstiburek summarizes how the principles of thermodynamics apply to building envelopes, and this is a good place to start as you explore continuousinsulation.org.

For additional information, please review the following articles, as well as the previous videos in this series:

Perfect Wall Articles

  1. Creating the ‘Perfect Wall’: Simplifying Water Vapor Retarder Requirements to Control Moisture
  2. Perfect Walls are Perfect, and Hybrid Walls Perfectly Good
  3. Wood Framed Wall Insulation Calculator Explained
  4. New Wall Design Calculator for Commercial Energy Code Compliance
  5. Energy Code Math Lesson: Why an R-25 Wall is Not Equal to a R-20+5ci
  6. Continuous Insulation Solves Energy Code Math Problem

Video Series

  1. Fear Building Envelopes No More with This Website & Videos
  2. Thermodynamics Simplified Heat Flows from Warm to Cold
  3. Moisture Flow Drives Water Induced Problems
  4. Video: How the 'Perfect Wall' Solves Environmental Diversity
  5. Video: How Important Is Your WRB?
  6. Video: A Reliably Perfect Wall Anywhere
  7. Video: The Best Wall We Know How to Make 
  8. Video: How to Insulate with Steel Studs
  9. Video: Thermal Bridging and Steel Studs
  10. Video: Better Residential Energy Performance with Continuous Insulation
  11. Video: How to (Not) Ruin a Perfectly Good Wall
  12. Video: Tar Paper and Continuous Insulation? No Problem!
  13. Video: Do CI and WRBs Go Together?
  14. Video: Assess Your 'Perfect Wall' Using Control Layers