Air movers can be generally classified as fans or blowers. Fans are usually axial fans or propellers that produce low-pressure air movement. Blowers, on the other hand, are usually centrifugal devices that deliver air at a higher pressure, usually for a process such as a reaction, as well as cooling. For a discussion of heat exchangers, see When fans are used to cool enclosures, they either draw air through the cabinet, or move it through an air-to-air heat exchanger. Although heat exchangers do not mix inside with outside air, they do pass heat to the environment. However, the technique isolates outside dirt and debris from sensitive components within the heating system. An airtight cabinet without a fan can dissipate heat but may require a large enclosure for a minimum temperature rise. Adding a fan improves the cooling process over convection and radiation alone by up to tenfold. When a fan is required for enclosure cooling, a washable air filter at the incoming air stream is recommended. When using air filters, a plenum must also be used to separate the fan from the filter and to maintain even, effective airflow. If a plenum is not used, the filter is placed against the fan reducing filter efficiency because 90% of the airflow passes through the tips of the fan blade. Carefully positioning the fan in the cabinet can avoid some common cooling pitfalls. First, placing a hot component, such as a transformer, in the incoming airflow may seem good for the transformer but subjects other components to unwanted heat. If possible, hot devices should be located near the exhaust so that their heat dissipates directly to the outside. Also, because axial fans have relatively low static pressure, their exhaust grill is often sized too small. To be safe, the size of the opening
Products & Services
Fans and Blowers (Industrial)
Industrial fans and blowers are designed to move air and/or powders in industrial and commercial settings. Typical applications include air circulation for personnel, exhaust or material handling.
HVAC Fans and Blowers
HVAC fans and blowers are used to move air through heating, ventilating, and air conditioning (HVAC) systems. They are an integral part of the air handling systems that bring or draw fresh air into buildings.
Heat exchangers are commonly used in a wide variety of industrial, chemical, and electronics processes to transfer energy and provide required heating or cooling.
Fan Blades and Propellers
Fan blades and propellers are used to convey power from a source (such as a jet engine) for propulsion or the movement of air. Propellers are an array of fan blades that transmit power by converting rotational motion into thrust. They are sometimes referred to as props.
Topics of Interest
4.4 Fan Heat Gain and Temperature Rise
4.4.1 Fan Heat
Fan heat is a significant cooling load that must be included in the cooling load calculation. Supply fans produce the largest heat gains,...
Oil filled transformers can generally take care of themselves, since they are seldom built into other enclosures. Dry types, however, are often purchased as core and coils with no...
Fans create a flow of air, which they can then force through equipment that needs cooling. The necessary output is determined from the flow rate and the required static pressure. If the airflow...
In most HVAC systems, the final energy transport medium is moist air a mixture of dry air and water vapor. This is conveyed through filters, heat exchange equipment, ducts, and...
Enclosure Types and Cooling Methods
There are various types of enclosures associated with DC motors. The following are the more common configurations found in industry. The system of cooling or...