Post by JW on Aug 20, 2008 21:41:46 GMT -5
This is the first installment of FANKILLERS, an educational series on how to get the longest life out of your fan by avoiding common mistakes that typical fan manufacturers will not tell you about.
This installment discusses running your ceiling fan on reverse. As you know, the reverse feature is a handy way to bring heated air down from the ceiling in the winter. However, this feature must be used correctly. It is recommended to run the fan on a low speed in the reverse setting, not only to avoid an unwanted draft and therefore a wind chill effect, but also to avoid premature injury or death to your ceiling fan.
Note: This lesson is directed primarily toward ceiling fans with electrically reversible motors. Some older fans, like Hunter Originals with Reversaire or Adaptaire, run counterclockwise regardless of how the blades are set and are thus safe from falling off the ceiling due to this condition.
As discussed in another thread, you should make the proper checks to your fan's "anatomy" to ensure that it is secure enough to withstand the torque of the motor turning the entire fan counterclockwise, therefore unscrewing it, while the blades turn clockwise.
First off, if your fan is attached to the ceiling by any form of mount covered by a BELL CANOPY or similar, lower the canopy to see if the fan is on a J-HOOK (which is a bolt in itself) or a U-BRACKET (attached to the ceiling or box by two screws or bolts). If your fan is attached with a J-HOOK, do not run the fan on high in reverse. The torque of the fan could cause the J-hook to untwist itself out of the ceiling, causing the entire fan to fall.
If your fan instead has a BALL-AND-SOCKET canopy, you still need to check and see how the downrod attaches to the ball. If it is a "normal" mount, the downrod should have a metal "pin" or "bar" running through the top, which rests on the inside of the top of the ball. (If you aren't certain, you will have to remove the fan from the ceiling to check this). Fans on which this feature first appeared, such as Casablanca, Emerson, and Old Jacksonville, may have a ball which simply screws onto the downrod with no further support. If this is the case, do not run the fan on high reverse.
If your fan passes both of these tests, the last step is to check the bottom of the downrod and how it connects to the motor housing. If the downrod is held in by a metal bar (usually with a flat head on one end and a cotter pin on the other to hold it in place), your fan is secure; however, you still need to tighten any set screws around the pin to minimize wobbling. If the downrod twists into the motor, it may or may not have the bar and pin. If this is the case, the set screws MUST be tightened as far as possible without damaging them, and you should not run your fan on high reverse.
Some fan manufacturers have limited the reverse speeds of their fans for best performance and possibly to compensate for the risks posed by running them too fast. Some spinners manufactured by CEC (Toastmaster), as well as some fans made by Kando, will only run at a maximum speed on reverse roughly equivalent to the low speed on forward.
In conclusion, running a fan on high speeds on reverse might have some advantages - for example, avoiding a direct current of air where one has loose papers but still wants a strong breeze. However, the fan should not be used in this way to redistribute heated air (except possibly on very high ceilings) - and it is important to check your fan's structure to make sure it can tolerate the reversed torque of the motor.
This installment discusses running your ceiling fan on reverse. As you know, the reverse feature is a handy way to bring heated air down from the ceiling in the winter. However, this feature must be used correctly. It is recommended to run the fan on a low speed in the reverse setting, not only to avoid an unwanted draft and therefore a wind chill effect, but also to avoid premature injury or death to your ceiling fan.
Note: This lesson is directed primarily toward ceiling fans with electrically reversible motors. Some older fans, like Hunter Originals with Reversaire or Adaptaire, run counterclockwise regardless of how the blades are set and are thus safe from falling off the ceiling due to this condition.
As discussed in another thread, you should make the proper checks to your fan's "anatomy" to ensure that it is secure enough to withstand the torque of the motor turning the entire fan counterclockwise, therefore unscrewing it, while the blades turn clockwise.
First off, if your fan is attached to the ceiling by any form of mount covered by a BELL CANOPY or similar, lower the canopy to see if the fan is on a J-HOOK (which is a bolt in itself) or a U-BRACKET (attached to the ceiling or box by two screws or bolts). If your fan is attached with a J-HOOK, do not run the fan on high in reverse. The torque of the fan could cause the J-hook to untwist itself out of the ceiling, causing the entire fan to fall.
If your fan instead has a BALL-AND-SOCKET canopy, you still need to check and see how the downrod attaches to the ball. If it is a "normal" mount, the downrod should have a metal "pin" or "bar" running through the top, which rests on the inside of the top of the ball. (If you aren't certain, you will have to remove the fan from the ceiling to check this). Fans on which this feature first appeared, such as Casablanca, Emerson, and Old Jacksonville, may have a ball which simply screws onto the downrod with no further support. If this is the case, do not run the fan on high reverse.
If your fan passes both of these tests, the last step is to check the bottom of the downrod and how it connects to the motor housing. If the downrod is held in by a metal bar (usually with a flat head on one end and a cotter pin on the other to hold it in place), your fan is secure; however, you still need to tighten any set screws around the pin to minimize wobbling. If the downrod twists into the motor, it may or may not have the bar and pin. If this is the case, the set screws MUST be tightened as far as possible without damaging them, and you should not run your fan on high reverse.
Some fan manufacturers have limited the reverse speeds of their fans for best performance and possibly to compensate for the risks posed by running them too fast. Some spinners manufactured by CEC (Toastmaster), as well as some fans made by Kando, will only run at a maximum speed on reverse roughly equivalent to the low speed on forward.
In conclusion, running a fan on high speeds on reverse might have some advantages - for example, avoiding a direct current of air where one has loose papers but still wants a strong breeze. However, the fan should not be used in this way to redistribute heated air (except possibly on very high ceilings) - and it is important to check your fan's structure to make sure it can tolerate the reversed torque of the motor.
