Kohler 20--2800 kW manual Air Requirements, General

Section 4 Air Requirements

4.1 General

An ample flow of clean, cool air is required to support combustion and dissipate heat. Approximately 70% of the heat value of fuel consumed by an engine will be rejected to the cooling system and exhaust.

Battery compartment ventilation. To prevent the accumulation of explosive gases, ventilate compartments containing batteries.

If a generator set is to be located in a building or enclosure, make certain that adequate air intake and air outlet openings are provided. If air flow provided by the engine-generator cooling fan is not sufficient to prevent excessive temperatures, other means such as ductwork and/or ventilating fans will have to be used to provide adequate air flow. If an exhaust fan is used, (Figure 4-1 and Figure 4-2) check the fan’s capacity in cubic feet (cubic meters) per minute. Follow the fan manufacturer’s recommendations to determine the size of the inlet and outlet openings.

In certain cold climate applications, controlled recirculation may be used as a means of heat recovery; however, special equipment such as thermostatically activated louvers and fans are needed to prevent engine and engine room overheating. The uncontrolled recirculation of heated air within an enclosure must be prevented. Otherwise, the temperature in the enclosure quickly rises to a point where efficient cooling is no longer possible. With a properly designed ventilation system, a sufficient temperature differential is not hard to maintain—even on the hottest days. Make certain air inlets and outlets cannot be blocked by snow. Air inlets and outlets should also be kept clean and unobstructed at all times. The direction of the prevailing wind should be considered when positioning outlets. If wind velocity is considerable, it tends to cancel the effects of the engine or exhaust fan. When strong prevailing winds are anticipated, face the air inlet into the wind and the outlet in the opposite direction. See Section 4.6, Liquid-Cooled Models, for additional suggestions.

Figure 4-1 Exhaust Fan-Operated Louvers (fan not shown)

Figure 4-2 Fans Required On Some Installations

TP-5700 7/93 Section 4 Air Requirements 11