Which factor does NOT contribute to the deterioration of a drive belt?

A drive belt can deteriorate due to several factors, and excessive heat, improper alignment, and high tension are all issues that can lead to wear and failure. Excessive heat can cause the material of the belt to degrade more quickly, leading to cracks and brittleness. Similarly, improper alignment can cause uneven wear and increased friction, further compromising the belt's integrity. High tension can lead to overstretching or deformation of the belt, making it prone to breakage.

In contrast, too much ventilation does not contribute to the deterioration of a drive belt. Adequate ventilation helps maintain a suitable operating temperature and can even aid in cooling the components of the system. Therefore, rather than causing harm, proper ventilation can be beneficial, making it the correct choice for the factor that does not contribute to drive belt deterioration.