Thread: Clearvue CV1800 / Max Impeller Install - Home Garage Workshop

Bob, the circumference of my cyclone body is 142cm so diameter is approx. 45cm. The diameter of the cutout for the blower housing intake is approx 200 mm but this is measured by ruler and eyeball from ouside the cyclone body. As you can see in the pic (hard to get a good photo) there is no lip aside from the thickness of the perspex

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Originally Posted by wodjie

I'd be interested in hearing what you think the noise is like after having the 2HP dusty.

Hi mate,

I took a quick measurement when I got home tonight. The 2HP dusty was 85.1 dB(A) at 1m and 81.3 dB(A) at 3m. This compares with 88 dB(A) at 1m and 83 dB (A) at 3m for the Clearvue. Note that these measurements were conducted; with both extractors in their current positions in the workshop (see pics) so the effects of reverberation may be a bit different for both, with the Clearvue set to 60 Hz and with both extractors running open inlets. Unfortunately I don't have an Anechoic chamber at home to take measurements in a free-field lol and I'm not about to drag both out into an open grass field.

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Originally Posted by DomAU

Wrt static pressure; understood. When I say curve I meant the system resistance curve and fan curves which are expressed as a Static Pressure vs flow.

Yeah, I expected that I was getting the Max impeller and housing but it appears I just got the Max impeller. My outlet is 8". Is this normal for a cv1800?

What about the inlet?

Originally Posted by BobL

What about the inlet?

The inlet is a rectangular to 6" round transition but as I ordered the CV1800 cyclone I assume this is as it should be.

Originally Posted by DomAU

The 2HP dusty was 85.1 dB(A) at 1m and 81.3 dB(A) at 3m. This compares with 88 dB(A) at 1m and 83 dB (A) at 3m for the Clearvue. Note that these measurements were conducted; with both extractors in their current positions in the workshop (see pics) so the effects of reverberation may be a bit different for both, with the Clearvue set to 60 Hz and with both extractors running open inlets.

Thanks for this. I'm running the 2HP all the time while I'm working (muffs on too) but I'm always thinking of noise. 4db doesn't sound like much difference, but I'd bet you do notice it, unless the noise characteristic/frequency is different. The 2HP fan does howl pretty badly, but some new 6" will make it work less.

Are you happy with everything so far?

Originally Posted by wodjie

Thanks for this. I'm running the 2HP all the time while I'm working (muffs on too) but I'm always thinking of noise. 4db doesn't sound like much difference, but I'd bet you do notice it, unless the noise characteristic/frequency is different. The 2HP fan does howl pretty badly, but some new 6" will make it work less.

Are you happy with everything so far?

While the sound pressure levels were only about 3dB (A) different, it's clear that the 2HP Dusty has more higher frequency content that is therefore also far more directional. I didnt use an integrating sound level meter so i dont have the 1/3 octave info but you can hear the difference. For the clearvue the bulk of the noise is below 500Hz. If I didn't take the measurements pointing the free field mic directly at the noise source the difference in levels would be greater. 85dB (A) is generally considered to be the limit for 8 hour daily exposure so it's unlikely the 2HP would be doing any significant permanent hearing damage and with ear muffs you'd be completely fine.

Yeah, so far I'm very happy. Before ordering i had concerns about the quality of the kit for the price and that there would be a lot of work to install it. But I found the quality of the parts to be very good and it hasn't taken long at all to put together. The fit and finish is not 100%, but I was pleasantly surprised rather than dissapointed. It's the performance that really matters and I couldn't find anything in Australia that I thought would work any better than the clearvue even at a higher price.

I'm hoping to fit most of the ducting this weekend and hopefully be using the system properly in the next two weeks (I'll need to modify machine ports to 6" etc). Also, the service from Stephen was very good, he forgot to ship a couple of items but sent them express as soon as I let him know, so very happy with the response.

I'm going to take some static pressure measurements later today and will try to get some proper airflow measurements along the way as well.

I was thinking more subjective tests of "hmmmm, thats a bit quieter". Noise tests can be like that, they register as louder, but our perception of frequency is different. Im thinking 85dB at high frequency would make you insane, but at lower frequencies it would be quite OK.

Originally Posted by wodjie

I was thinking more subjective tests of "hmmmm, thats a bit quieter". Noise tests can be like that, they register as louder, but our perception of frequency is different. Im thinking 85dB at high frequency would make you insane, but at lower frequencies it would be quite OK.

You are quite right. We have equipment and software at work that can analyse sound wrt "psycho-acoustics" eg. Harshness, loudness and sharpness. Like you say, for two sources with equal spl levels one may be perceived as a lot "louder" or harsher. I would say the clearvue is louder but the 2HP is more irritating / harsh.

Also, max static pressure at 60Hz was 360mm h2O and for the 2HP was 178mm. Both with filters/exhaust connected.

Originally Posted by DomAU

You are quite right. We have equipment and software at work that can analyse sound wrt "psycho-acoustics" eg. Harshness, loudness and sharpness. Like you say, for two sources with equal spl levels one may be perceived as a lot "louder" or harsher. I would say the clearvue is louder but the 2HP is more irritating / harsh.

Also, max static pressure at 60Hz was 360mm h2O and for the 2HP was 178mm. Both with filters/exhaust connected.

It would be interesting too know the SP at 50Hz for the Cleavue.

Originally Posted by BobL

It would be interesting too know the SP at 50Hz for the Cleavue.

You know I actually did check at 50Hz and even 63 and 70hz but didn't write those down and now wouldn't trust the numbers from my memory. I'll re-test and let you know.

Originally Posted by DomAU

You know I actually did check at 50Hz and even 63 and 70hz but didn't write those down and now wouldn't trust the numbers from my memory. I'll re-test and let you know.

Probably OK for an SP test because the motor will not draw as much current, but I would be careful about going above 60Hz with a 16" impeller for anything else as the current drawn by the motor could be greater than the motors capability. This is where having a VFD rating to suit the motor or a VFD that allows a current limited to be set.

Originally Posted by DomAU

You know I actually did check at 50Hz and even 63 and 70hz but didn't write those down and now wouldn't trust the numbers from my memory. I'll re-test and let you know.

Ok. Here it is;

50Hz: 252 mm
60Hz: 360 mm
63Hz: 385 mm
70Hz: 470 mm

This is for the cyclone in its current state with cyclone mounted and 3m of HVAC exhaust ducting venting outside through a roof vent.

Has anyone else measured the Max static pressure of a clearvue cyclone, cv1800 or cvmax? I'm curious to see if the 16 vs 15 inch impeller makes any difference to this.

Originally Posted by DomAU

Has anyone else measured the Max static pressure of a clearvue cyclone, cv1800 or cvmax? I'm curious to see if the 16 vs 15 inch impeller makes any difference to this.

Me too. Bill Pentz advised me in discussions I had with him during testing and evaluation of running the cyclone in Oz that we stick to an upper limit of 70hz. His reasoning was that a material collision with the impeller could be contained in the housing if the speed was held to those figures but there has been at least one collision that penentrated the housing and that was below 60hz IIRC. I have always wondered what the fan curve does above 60hz and where the point of no return for an increase in speed occurs. I suspect that the entry and exit of the housing may well be the bottle neck and in the US they have found that 7" duct on an 1800 gives far better results. Try buying 7" duct in this country and people look at you strangely as if you should be committed. A very interesting thread, what current does the system run at with blast gates open?