One of the most common mistakes someone can make when building a Frankencooler is allowing air to get around the heat exchangers (radiators). When running, the blower(s) on a Frankencooler are working hard to pull air through multiple heat exchangers, and even a small gap can draw in hot air that can severely compromise the cooling effectiveness. A good quality, dense, foam tape is your best friend for sealing heat exchangers to surfaces. HVAC foil tape and silicone sealer are also handy in some applications.
Even if you’re using a 12V power plug for juice, pay attention to manufacturers’ stated amperage draw specifications when choosing pumps and blowers for your project – lower is better. This is doubly critical when running off of a power cell/small battery as even .5 amp can make a big difference in running time.
Keep the air chamber as small as possible. The area under the cooler lid and above the thermal barrier should be just big enough for the heat exchangers and tubing. Use 90-degree fittings on your heat exchangers to route water tubes more tightly, keeping the area as shallow as possible and allowing for a thicker insulative panel and more ice storage below.
For maximum cool, do not operate blower(s) at full speed. Inline blowers of the type used by Frankencooler are powerful. Run at full speed, they can pull air through heat exchangers so fast that the transfer of heat (cold) is compromised. You’ll find that a range of around 50 – 75% blower speed provides a ‘sweet spot’ of strong airflow combined with maximum cooling.
Consider the surface. The asphalt parking lot surface we tailgate on, even in the shade, is extremely hot. Being a cheapskate, my Frankencoolers are built from inexpensive coolers that don’t benefit from 3″ of solid foam insulation on their bottoms like a Yeti and the radiating heat takes a toll on the ice. Consider laying down a piece of foam board insulation like you used in your build underneath the cooler. If you don’t have foam board on hand, even a folded towel will help conserve ice.
