Ceiling fans now need a quality rating system check and public statement of that inspection. There are five sections to this QRS and each must be met the standards set by the government in order to be sold to the public. For each fan in the store, there is a public document stating that fan's QRS levels. The five sections tested are quality, CFM (cubic feet per minute) airflow, wind speed, efficiency, and watts of electricity used.
The quality rating measures from 1 to 5 with 5 being the best. It tests how well the fan was made, the noise level, the smoothness of the turn and the projected longevity. For this and more than any other section of the test, ceiling fans with a quality score of 4 or 5 are recommended.
CFM airflow measures how much air the fan can move in the room. There is a graph of the CFM airflow on the QRS sheet showing the levels while the fan is on high speed. This measurement is second only to quality in helping to make a ceiling fan choice. A CFM of 1400 or lower is the worst score where 10,000 CFM is the best possible. The range in CFM is due to the fact that not all rooms are the same size and a lower CFM is needed for a smaller room.
The wind speed is how well the fan will be able to cool off the room. This is done by a chill effect not the actual wind that moves. This measurement takes into account the CFM and blade span when calculated and figures out the wind velocity just beneath the fan. A large fan will create a larger column of air under the fan and therefore a lower wind speed causing the entire room to be cooled where a smaller fan will concentrate on the area beneath the fan.
The ceiling fan's efficiency is the CFM divided by the number of watts needed. This formula calculates the amount running the fan costs compared to the amount of comfort the fan affords the room. This rating is important but not nearly as important as the CFM simply because a good rating in efficiency will usually only save about $10 a year whereas a good rating in CFM will save on heating and air conditioning costs year round. The better way to get more air flow is to have a higher powered engine. This quality test is measured for the amount of energy the fan pulls when set at the highest level. It is best to have lower watts rather than higher but, again, the more power, the better the airflow and thus the better the CFM. This is not a very important criterion as virtually all ceiling fans use very little electricity to run at high speed.
Modern Ceiling Fans is a comprehensive information source on fans that are attached to the ceiling to include the flush mount, remote as well as vintage ceiling fans, their accessories and everything else you need to know.
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