Golf Course Management

DEC 2013

Golf Course Management magazine is dedicated to advancing the golf course superintendent profession and helping GCSAA members achieve career success.

Issue link: http://gcmdigital.gcsaa.org/i/215757

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gcm ex t ra The most commonly misunderstood compressor rating is cubic feet per minute (CFM). Generally, the ideal solution is to look for an engine with more than enough power needed to turn the pump. Otherwise, if the engine is underpowered for the unit, it will constantly run under high stress, leading to premature failure. 72 GCM December 2013 RPM. However, the formula only calculates displaced CFM. Because of factors like atmospheric pressure, temperature and friction, compressors actually produce less air than this number implies. To more accurately measure performance, other rating systems have been developed. For instance, standard CFM gives the volume of a unit according to certain conditions, such as 14.7 PSIA, 60 degrees ambient temperature and zero percent relative humidity. Actual CFM is another rating system that calculates the true output of the compressor at real-life operating conditions. Because there is no gold standard in the industry for rating CFM, manufacturers are basically free to advertise whichever number they prefer. Some companies rate their compressors with the actual CFM, while others state the larger displaced CFM number. Regardless of the rating method, the most important point is to not compare apples with oranges. In other words, a unit advertised with a displaced CFM shouldn't be directly compared with another stating the actual CFM. In this case, the best approach is to ask for the actual CFM of the frst unit and then make a fair comparison of the compressors' air volumes. The driving force Another specifcation that often gets confused is horsepower. For gas-powered compressors, this isn't as much of an issue. The horsepower ratings on these units are fairly straightforward, making comparisons easier. Generally, the ideal solution is to look for an engine with more than enough power needed to turn the pump. Otherwise, if the engine is underpowered for the unit, it will constantly run under high stress, leading to premature failure. On the other hand, electric motors aren't as well understood. A person may believe he has a 5.5-horsepower unit when it really only operates at 1½ horsepower. This is the difference between peak and continuous horsepower.

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