Posted on 20th Sep 2010 @ 4:33 PM

Effective Ventilation Design: It's a Matter of "Push & Pull"...

Effective Ventilation Design is not rocket science by any means but it is truly amazing how many systems we've seen with plenty of fans but no ventilation.

Rule #1: Out goes the humid air, in goes the dry.

We have seen many, many systems with fans fastened with Rube Goldberg-type clips, goosenecks and other make-shift attempts to blow air directly onto the water. THE most important concept to understand is that you must have a source of cool, dry air and an exhaust port to vent out the hot humid air. Simply moving air around inside a closed space accompished nothing except waste electricity and prematurely rust your door hinges.

Rule #2: (For the canopy or upper cabinet) Pull hot air out by pushing cool air in.

This may seem ridicuously simple but consider: Hot air rises. You need to do nothing to collect the hot air in the warmest part of your tank, which always the canopy or upper cabinet. You just need to place a fan connected to an opening to effiiciently exhaust the hot air. Now, if you have TWO fans drawing cool air from the lowest points in your aquarium canopy, they not only draw in cool air but they PUSH the exhaust fan. By creating slight positive air pressure, the exhaust fan works most efficiently. The exhaust fan will crank out much more hot air if it is being "pushed".

Rule #3: (For the base cabinet) Pull the cool air in by pushing the hot air out.

This is almost the opposite case but not exactly. Thermodynamics in the canopy are very differnt from the base cabinet. In the base cabinet, humidity and heat will accumulate. That heat, which is right under your tank, if not vented, will transfer heat via high humidity, to the tank itself. It will also quickly corrode door hinges and just be troublesome. In this case, we want to do just the opposite: We want two fans pulling out warm, humid air and a single cool air source. In this case, you can certainly have two fans drawing cool air in.

If possible, a lower cabinet draw inlet from under the house (crawl space) is ideal. We will add more detail to this article soon. Check out the above schematic.