On Monday November 11, electricians installed the second fan I purchased for the King's Room, a Casablanca Stealth in Graphite with Dark Walnut blades. Though not quite as thin and sexy as the Haiku fan, it is also very nice looking and contemporary. The Walnut blades matched the color of the Haiku Bamboo blades as exactly as I could determine.
But when the fan was powered up to top speed, I heard a small bit of chuffing noise. Chuffing was also one of the ways I described the Haiku fan at it's 4 highest speeds. The noise had some similarities, but was also quite different, mainly from being far lower in level. I'd guestimate the noise to be 20-30dB lower, or about 100-1000x less energy. It also didn't have the peculiar double-chuffing sound that's characteristic of a helicopter. This was more random, less complex, more like flipping a deck of cards.
There also seems to be a little instability at the top speed. The gap between the motor housing and the lamp changes rapidly, and it almost seems like the motor itself is shaking a bit. But you only see that movement close up, from 8 feet away the fan looks perfectly stable.
I worried for the first evening that maybe the electrician had not attached the blades with perfect alignment, and that perhaps there was some imbalance. However, the instability occurs only at the very top speed. At lower speeds, the fan is perfectly stable. If there were any static imbalance, it would actually become more visible as the fan slowed down. Then I also observed that at the second-from-top speed, the fan is perfectly stable looking, and the chuffing sound is almost undetectable, being perhaps another 20 dB lower.
All this evidence fits the interpretation that there is something constant about the room that was affecting both fans, and I now strongly believe it is the vaulted ceiling that puts a strange load on the fan blades, and that is the underlying cause of the noise. With a perfectly flat ceiling, both fans might be much quieter. The DC motor of the Haiku is servo controlled and electronically reacts to the strange load, resulting in the double-chuffing heliocopter sound. The AC motor of the Casablanca also reacts, but at the level of the laws of electromagnetic forces, hence a simpler single-chuffing sound, and possibly greatly reduced by the much higher mass of the Casablanca Stealth.
The Casablanca Bel Air fan is quieter than the Stealth, and much more stable looking at top speed, but if I were to move the Bel Air into the Kings Room under the vaulted ceiling there, it might well be noisier and equally unstable at the highest speed. Or worse! The Bel Air is significantly lighter than the Stealth, and so it might react even worse to the vaulted ceiling than the Steath.
Anyway, I'm quite happy with the second-from-top speed of the Stealth, and it probably provides most of the cooling I need. It is far quieter than my pedestal fan at any speed. A good ceiling fan is a wonderful luxury in an already fully climate controlled house.
But when the fan was powered up to top speed, I heard a small bit of chuffing noise. Chuffing was also one of the ways I described the Haiku fan at it's 4 highest speeds. The noise had some similarities, but was also quite different, mainly from being far lower in level. I'd guestimate the noise to be 20-30dB lower, or about 100-1000x less energy. It also didn't have the peculiar double-chuffing sound that's characteristic of a helicopter. This was more random, less complex, more like flipping a deck of cards.
There also seems to be a little instability at the top speed. The gap between the motor housing and the lamp changes rapidly, and it almost seems like the motor itself is shaking a bit. But you only see that movement close up, from 8 feet away the fan looks perfectly stable.
I worried for the first evening that maybe the electrician had not attached the blades with perfect alignment, and that perhaps there was some imbalance. However, the instability occurs only at the very top speed. At lower speeds, the fan is perfectly stable. If there were any static imbalance, it would actually become more visible as the fan slowed down. Then I also observed that at the second-from-top speed, the fan is perfectly stable looking, and the chuffing sound is almost undetectable, being perhaps another 20 dB lower.
All this evidence fits the interpretation that there is something constant about the room that was affecting both fans, and I now strongly believe it is the vaulted ceiling that puts a strange load on the fan blades, and that is the underlying cause of the noise. With a perfectly flat ceiling, both fans might be much quieter. The DC motor of the Haiku is servo controlled and electronically reacts to the strange load, resulting in the double-chuffing heliocopter sound. The AC motor of the Casablanca also reacts, but at the level of the laws of electromagnetic forces, hence a simpler single-chuffing sound, and possibly greatly reduced by the much higher mass of the Casablanca Stealth.
The Casablanca Bel Air fan is quieter than the Stealth, and much more stable looking at top speed, but if I were to move the Bel Air into the Kings Room under the vaulted ceiling there, it might well be noisier and equally unstable at the highest speed. Or worse! The Bel Air is significantly lighter than the Stealth, and so it might react even worse to the vaulted ceiling than the Steath.
Anyway, I'm quite happy with the second-from-top speed of the Stealth, and it probably provides most of the cooling I need. It is far quieter than my pedestal fan at any speed. A good ceiling fan is a wonderful luxury in an already fully climate controlled house.
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