Here’s an excerpt from an article and podcast from GreenBuildingAdvisor.com which provides a really nice explanation of how heat moves through buildings. If you haven’t read my earlier post on Passivhaus design, you can have a gander at that too.
The Basics of Heat Flow
As construction methods and materials change, and energy gets more expensive, how and why we insulate our homes become more important.
Why insulate?
- For thermal comfort
- To save energy
- To stop condensation and the potential for mold and rot
- To reduce the size, cost, and complexity of our HVAC systems
In order to slow the flow of heat through our foundations, walls, windows, and roofs, it helps to understand what heat is and how it moves.
What is heat?
- Heat is energy in the form of vibrating particles
- The faster the particles move, the farther they move apart — slow particles make solids, faster ones turn to liquids, and even faster ones become gases
How can it move?
- Conduction: solid things touching other solid things — drywall touching wall studs touching plywood
- Convection: fluids, like water or air, moving around in an open space, like a pipe, wall cavity, or room
- Radiation: heat in the form of electromagnetic energy moves through open space — the less stuff in the way, the better
