Thursday, March 6, 2008

How does a greenhouse work?

Some of you may wonder how a green house takes solar energy and turns it into thermal energy. A good example of this is something you can observe every day in the summer in you own car. It happens when you leave you car in a sunny parking lot with the windows up. The solar energy is passing through the glass and is heating the cars interior.

Whats really happening is the short wave infrared waves are going in and are turning into long wave infrared waves, which cannot escape. So they just reflect around and get absorbed by their surroundings. This of course is the ideal setup to grow plants. And thus you green house helps your plant grow.

The infrared light waves are invisible to the naked eye, they lie between microwaves and visible light waves in the light spectrum. Other waves include UV, and opaque. We all know all about infrared, we may just not know it. Its what you feel when you stand next to a fire, its lying in the sun and sweating, or huddling up for warmth.