It's all about ENERGY

This word hit me as I followed how cyclone Yasi unfold itself. The weatherman described it as an "energy system moving across...". That's a very concise description and a "massive energy system" indeed.





It also reminds me of the time when I studied bird house designs. In essence we are trying to emulate a cave environment - its temperature & humidity stability. Natural caves are in massive limestone hills that insulate it from external environmental fluctuations. Constant water sip-page helps to maintain high humidity within. Air exchange through cave entrances/openings maintain oxygen supply to sustain life. Dark cavities offer safe sanctuary from predators. Swiftlets must have its echolocation capability develop and evolved over tens (hundreds?) of thousand years.















In the case of bird house, the walls are egg shell in comparison. Climatic changes have direct impact to its micro-environment. It is common knowledge daily cycle of sun's heat has direct influence, the dominant factor in fact. If one observes the daily temperature cycle inside a bird house, it typically peaks around 4-5pm and coolest around 4-5am.

In a nutshell, it is the movements of thermal energy in/out of the bird house in daily and seasonal cycles. The thermal insulation properties of the building materials are basic to design considerations. First thing I did was to dust off my old physics book for a refresher on thermodynamics. Understanding heat and thermal energy is fundamental.















So it is all about thermal energy in every aspect of bird house micro-environment design. I have a mental picture of an underlying thermal model when taking each design consideration; may it be orientation, humidity, air-exchange etc. They are all inter-related.

In depth understanding of this subject would certainly help to improve one's bird houses to the next level.