Air-Flow-Basics

By adam
May 14, 2010   Leave a comment

These simple concepts will allow you to understand how your home uses energy to increase comfort.

Air-Flow Basics

  • A hole and a driving force are needed for a building to leak.
  • A driving force can be anything…. Wind, Heat, Fans, Clothes Dryer, Dirty Filter, etc…
  • Air leaks through the hole of least resistance.
  • If some air exits the building, an equal amount enters elsewhere.
  • The Stack Effect is natural. Warm air rises and cool air falls.
  • Air moves towards a place of lower pressure.
  • Air carries things: Hot/Cold, Wet/Dry, Birds/Planes, Pollutants/Toxins

Heat Loss: Convection, Radiation, Conduction

  • Convection happens when there is gas/air between surfaces of different temp/pressure.
  • Radiation happens when there is a direct line of site between two surfaces.
  • Conduction happens when two sides of the same solid object have different temperatures.

So …

The more air-tight a building, the better we can control the temp/RH%. Once we have an airtight space, insulation surrounds it, and additional layers/boundaries may be used to strategically protect against unwanted Convection, Radiation and Conduction.