Engine Compartment Air Management for Engine Cooling and Air Conditioning System Performance

Engine Cooling and Air Conditioning tests were performed using a sports utility vehicle with a V-6 engine. The original vehicle was equipped with an engine driven fan. This vehicle was modified by adding electric motor driven fans, air path sealing and advanced heat exchangers in a predetermined test configuration. Engine cooling performance and air conditioning performance were evaluated at each step. Identical grade load and idle tests were conducted with this vehicle at each step.

The V-6 sports utility vehicle was selected due to its use of an engine driven fan. The grade load of 8.7% was selected due to off road use by the consumers.

The results of the testing showed that engine cooling performance and air conditioning performance were improved by using electric motor driven fans, air path sealing and advanced heat exchangers. This improvement was demonstrated both on the grade and during idle immediately following the grade accordingly:

• lower coolant temperature
• lower coolant system pressure
• lower transmission oil temperature
• lower engine oil temperature
• lower vent outlet temperature
• lower compressor suction pressure
• lower compressor discharge pressure
• higher engine compartment air flow.