With electrical and electronic equipment one of the primary secrets to long, trouble-free life of the gear is keeping it cool. So, when you are selecting equipment and trying to figure out where you are going to mount it, consideration for air circulation needs to be made. The good news here is that as things continue to migrate towards totally solid state design, this task has gotten a little bit easier in that much of this equipment simply runs a bit cooler inherently. But, even with that fact in mind, proper air circulation around the back side of most electronic equipment is still a concern.
To achieve adequate cooling, some minor modification to your boat may be necessary if you load up a closed space with gear like battery chargers, inverter/chargers, or traditional diode type battery isolators. Keep in mind that it is not just the heat generated by the component we need to think about here either. Engine spaces, often where some of this gear ends up, can get pretty warm on a sunny July day after a long run. Overhead lockers on fly bridges or steering pedestal mounted pods on sailboats can get pretty toasty sitting in the hot summer sun. Louvered vent plates are a simple solution in many cases and these are readily available at just about any marine supply store. If the device in question has any cooling fins on it, or a louvered opening in the case with a fan behind it, consider it vulnerable. Examples are shown below:
The chart plotter shown above will generate some heat from its display screen backlighting as well as its internal power supply. The fins are cast into the case to help radiate this heat away. They’ll work a lot better if comparatively cool air is circulating over the fins.
The inverter above has a built in cooling fan, but the compartment it’s installed in may still need a vent opening to get the hot air out, find a place to cut out and install a louvered vent or two.
In some cases, addition of a small “pot” fan may be necessary. Just remember if the area in question shares space with a gasoline engine or fuel tank, these are not rated for “ignition protection” which is a requirement for electrical components installed in these spaces. The one above came from Radio Shack, and cost under $10. These can be set up to run only when the electronics are turned on.
What’s the magic temperature you may be asking? Several Standards come to mind. The NMEA installation standard states “sufficient means shall be provided to supply circulation of air behind equipment displays.” Further it states: for devices that use cooling fans, ” there shall be sufficient air circulation to cool the equipment during direct sunlight operation with ambient temperatures of 100 degrees F.”
ABYC Standard A-31, which covers inverters and battery chargers requires that the equipment be designed to operate at an ambient temperature of 122 degrees F (50C) and be able to withstand an ambient temperature of 158 degrees F or 70 C. Keep in mind that those values are not categoric, other equipment may need to run cooler.