AZFlow coolers and Improved reliability and availability
As stated above, aspen pad and recirculating evaporative coolers have a history of failures with high consequence that include: stuck float valves resulting in flooding and water damage; thrown blower drive belt physically damaging the float valve and recirculating pump; and galvanic corrosion causing structural failure of motor vibration dampers resulting in separation of the drive motor from the foundation. Without constant attention and preventive maintenance some failure should be expected for each operating aspen pad or recirculating cooler during the course of the cooling season even when the coolers start with new pads, pumps, floats, and belts. The outage duration associated with these failures vary with the specific failure, availability of spare parts, and design features to support repair and replacement. The experience of facilities with more than 4 coolers is that one person is usually fully occupied in conducting repair and maintenance of the coolers.
Contrary to the above, AZFlow coolers have no pumps, floats, or blower belts (tubeaxial fan models), and are designed to have few active high reliability components such that no failures are expected for several full seasons of operation. The few active components include the blower motor, the water metering solenoid valve, and the control system with each of these selected for their reliability and performance. Additionally, the cooler control system both self monitors performance and provides the ability for maintenance personnel to monitor and quickly diagnose performance issues from their desktop. For example, if the control system determines that a sensor is out of calibration it will send an alert and apply a predetermined compensatory action that will support continued operation in a safe and reliable mode until it is convenient to perform maintenance on the sensor.
Media change out in the AZFlow coolers is expected to be an infrequent activity but the cooler is designed so that this can be performed quickly and with limited manpower.
The blower and cabinet are designed with graded materials such that the cooler is expected to have a life well beyond the 10 year warranty. The term "graded materials" means that the materials used in the fabrication of the various components were selected consistent with the environment the components are expected to see during their operating life. To this end, the wet section is made of stainless steel and the blower casing and frame are made of galvanized steel. To avoid galvanic corrosion between dissimilar metals a dielectric material is used to electrically isolate the components.