Dick, we always advise a cooling fan for maxium motor/pump life. Its no different than a car engine that needs cooling in the winter or summer as the air temp does little to cool the engine . Pulling volumes of air through a confined space will give you maxiumm life out of your pump.Think of it as a fan that cools the radiator on your vehicle. It will still feel hot to the touch but will give you many more years of service. Consider this if your pump produces 5 CFM (give or take) a small cooling fan is 105 CFM and we have ramped up the cooling fans on the new Brookwood piston pumps to 290 CFM. Excessive heat is the main culprit on any type of motor. I realize your trying to be as cost efficient as possible and you can buy many $40-$100 pumps for what a cabinet with a cooling fan costs.I list cabinets with cooling fans on my site.Ted
