Originally Posted by DeepFrz
Every engine bay should be ventilated. The engine needs fresh air and will run better on cooler air. Make sure the inlet and outlet vents are outside with the inlet vent low in the engine room and the outlet vent high in the engine room. Often there is an exhaust
fan on the outlet vent so the inlet vent needs to be larger in size in order to supply enough cool air for cooling
the engine room and for combustion air. A fan or vent hose directed at an alternator
can help keep it cool. Engine room temperature should not exceed 125 deg f or 52 deg. c.
That's all very good advice.
Not only your alternator, but your engine, and just about everything else in your engine space, needs plenty of cool, fresh air. Ventilation is paramount. Your engine will have less power and run less efficiently if you don't feed it cool air, and alternators and other such equipment
won't be as efficient and won't last as long if you don't keep them cool.
Besides what DeepFrz recommends, I would suggest a temperature sensor in the engine space to keep an eye on the ambient temperature in there.