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DIYer Makes Cannon Quieter

Bill is an expat living in the hills northwest of Beijing, and he uses his DIY Cannon to cut the particulate in his home.

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But Bill wanted to improve on the biggest downside of the Cannon–it’s a bit loud on high:

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So Bill designed a sound dampening box for the Cannon out of foam blocks:

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There are openings in the front and back to let air through, although my guess is this lowers effectiveness by at least a few percent.

To further cut down on noise, Bill wrapped the Cannon with a blanket:

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With all that padding, Bill measured a 6 decibel drop in noise! If you have a Cannon already, here’s an idea of what that’s like: That’s 2 decibels quieter than the regular Cannon on low (52 db).

If the noise gets to you and you don’t mind a craft project, I sanction it! However, keep in mind two things:

  1. Monitor the fan temperature. Make sure your design does not allow the fan to overheat.
  2. I suspect this will lower effectiveness by at least a few percentage points. I can’t say more precisely without testing it.

Great work, Bill!

 

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Noise

The new Cannon kicks butt (scientific definition of kicking butt), but it’s noisier than the Original DIY. How noisy is it? As is my habit, I wanted to answer this question scientifically.

So I bought a decibel meter:

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And I tested the Cannon, Original DIY, Blue Air 203/270E, and IQ Health Pro Plus on their highest settings from 1.95 meters away. Here are the results:

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The cannon is noisier than I’d like, but it’s similar to the Blue Air on the high setting. To give you an idea of how loud that is, this decibel chart says that’s between “conversation at home” and “conversation in restaurant.”

It’s still louder than I’d like, but fortunately I’ve found that the Cannon is still very effective on the lower settings:

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So I recommend running the cannon on a lower setting if you find it noisy.

Conclusions: 

  1. Cannon-owners can use the lower settings without sacrificing much performance.
  2. For people who are particularly sensitive to noise, the Original may be a better choice.
  3. For people who are VERY sensitive to noise, the Philips AC4072is expensive (2,700 RMB), but it’s quite quiet on the low setting.

As always, I’m posting the data and methods below for fellow nerds.

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