There are times when rotary screw air compressors must operate in high ambient temperatures, leaving questions about the impact on these vital machines. What follows is an overview of what’s possible in these conditions, along with advice for ensuring the optimal performance of these air compressors in hot ambient conditions. Although all air compressors compress air, there is a difference in how centrifugal, oil flooded rotary screw, oil free rotary screw, piston and scroll machines compress air. Because this article focuses on rotary screw air compressors, it’s important to know the difference between oil free and oil flooded air compressors. This can be understood in part by looking at the actual air compressor component, which is often referred to the “airend”.