Monday, January 12, 2009

Heater Hacking Part II - But Wait...

After spending a bunch of time (not to mention cash) on integrating a heater in to our Coke fridge, we discovered something amazing/annoying.

The Coke fridge will heat itself.

The existing cooling system includes two high speed fans located inside the fridge. These fans pull air across a radiator (or exchanger or whatever it is called) and direct a sheet of cold air down the front of the fridge. I assume this is to achieve an air-curtain effect to minimized the loss of cold air when the door is opened.

Even when the compressor is turned off these high speed fans are still running. And guess what? The fan motors generate heat. DUH! So with the door closed, the compressor off, and the fans running the temperature inside the fridge slowly climbs. We went from 61F to 73F in about 30 minutes. Amazingly, this is actually TOO HOT. We need about 65F max.

Sigh.

So Shawn is going to figure out how to wire the system so that by default the fans are off. When we need a little heat, the fans will kick on. When we need to cool the fans and the compressor kick on. Simple, right?

Right.

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