An air compressor system is disclosed that includes a housing sized to enclose an air compressor pump as well as a dryer structured to remove moisture from air that is compressed by the compressor pump. The air compressor pump may be intermittently placed into operation, but the dryer itself is structured in one form to continuously maintain a heat exchanger in a desired temperature range in anticipation of operation of the air compressor pump. The heat exchanger of the dryer can include sufficient thermal mass such that a refrigerant pump of the dryer need not be operated continuously in anticipation of operation of the air compressor pump. While a cooling air flow can be created by operation of the air compressor pump, when the air compressor pump is not operated a cooling fan can be used provide cooling to the heat generating components of the dryer.