Thread: Sound Insulation

Originally Posted by Chris Parks

I have a good reason to slow mine down and it works. I tune two stroke motors as part of racing in superkarts so I slow my DE down enough that it captures all the smoke and gets it outside the shed. I just run a length of flexible line to the exhaust and it captures all the smoke.

The original reason we started using VFD's for the Cleaview Cyclones was because the Leeson motor was multivoltage and it allowed us to run 230V three phase at 60hz and as Bob pointed out it ensures a gain of at least 20% but I think it is slightly higher than that IIRC. Now we have begun using Ozzie supplied motors we still use a VFD to run it at 60hz. No amount of design will lift the airflow to what can be had with 60hz, if you can do it let me know how and I will save a lot of people a fair bit of money.

As I thaught, the motor and the system you are supplying is not specificaly designed for Australian market and Australian supplies and running it on 50 Hz disadvantaged it to the tune of 20%.

A small amount of design would definitely lift the airflow to what can be achieved at 60Hz

If the system was properly designed for the australian market, the impeller would be designed to run at motor speeds dictated by our 50Hz supply.

So instead of building a product that properly suits the australian market, you add an additional expense and introduce a variable frequency drive.

Yeh I get it now.

cheers

Originally Posted by soundman

So instead of building a product that properly suits the australian market, you add an additional expense and introduce a variable frequency drive.

Chris is not building anything. He's importing and assembling a few % of a premade product made specifically for the US. If the impeller/housinbg/fittings were to be designed and made specifically for the small numbers that would be imported into Australia the cost to the buyer would be much more than the cost of a VSD. VSD control also adds much more than frequency/RPM control. eg On a DCs, Ramped/soft starts reduce high current draw at start up which protects circuits etc.

So we have confoirmation that we have a product not designed for the Australian market do we.
And one that is fundamentally disadvantaged to the tune of 20% because of it. an additional expense is require to make it perform to specification.

So soft start is much more is it.....every other motor in our workshop draws large amounts of current on start up......its a realtivly small problem with blowers because they by their nature start off load.

If the circuits where properly designed and within capacity, they should require no other protection that provided by AS3000.

This then brings up a fundamental problem with cyclonic dust extraction.....the inherant air flow inefficiency, huge airflow losses and the large motors and blowers required to compensate for it

I came to the conclusion over 10 years ago that reticulated dust extraction and cyclonic dust seperation where of very questionable viability in small workshops, because of these losses, the losses in the ducts, and other practicalities.

It seemd plainly rediculous that I would need a 5Hp blower to produce the same airflow I can achieve from 2Hp using standard extractors close to the machine r with very short ducts.....and ya still have to expend on filtration

Combine with that the loss of performance to the tune of 20% or the cost of patching that up.

The whole idea is a white elephant

cheers

It may well be a white elephant, but I like mine a lot.

Three months ago I had a serious dust problem. As I waded through the possibilities to fix the problem a wish list was drawn up:

1. I wanted a ducted system so I was not dragging machines around the workshop.
2. I wanted to vent outside.
3. I wanted a small footprint (so I could keep the system in the shop and did not need to build a shed outside for a dusty).
4. I wanted to achieve the magic numbers of 1000 and 4000 so I had a shot at capturing the very fine material and at avoiding clogged lines.

I looked at the web to see what was around. I went to Carba Tech and to Gregory Machinery to judge the suitability of their offerings. In the end, the decision, for me, was easy. The cheapest solution that met all my needs was a Clear Vue. In fact it was the ONLY system that ticked all the boxes on my wish list.

It is not necessary to use a VFD to get good results with a Clear Vue. Even at 50 Hz it is no slouch; or you could get the Max version which was specifically designed for markets that use 50 Hz power ... that way you could put your hand on your heart and claim you were using a product designed for the Australian market ... if that was your objective.

But why would you? I got the system that met my needs. My workshop stays clean. I breathe clean air.

If this system was designed for the Greek, Finnish or Vietnamese markets, I could not give a hoot. All I care about is that it works and represents value for money.

It works ... very well.

It was the cheapest solution that met all of my wish list points.

We all have differing needs and priorities. What's best for me will not be best for everyone ... but I do like my Clear Vue ... a lot.

Found another reason to like my VFD.

The system ran well until about Chrissy time. Since then I have had power issues on and off.

The problem is that when everyone is at home on holidays and it gets hot, they all turn on their air-conditioners. The power supply drops enough for me not to be able to spin the cyclone at 60 Hz. So, I dial it down to 55 or 50 Hz, and it works fine.

I only have 10 Amp outlets in my shop, so it looks like I might be up for an upgrade to avoid this issue in the future.

Talked to a sparky about my power supply to the shed issue. He knew my house, having worked on it before, and reckoned a 15 Amp circuit to the cyclone would cost about @$2,000.

Cough ... splutter ... gasp, and wheeze. Time for a second quote.

Second sparky turned up this morning. Not only did he put in the 15 Amp circuit on the spot, he used 20 Amp cable because it was a long run. Then he changed the circuits so all other shed outlets were on one circuit (house and shed were together before, now shed has its own circuit breakers), and upgraded the cable from the board to 4.5 mm because of the longish run. Total cost was $630.00.

So, all is well in my world again.

Originally Posted by John Samuel

Talked to a sparky about my power supply to the shed issue. He knew my house, having worked on it before, and reckoned a 15 Amp circuit to the cyclone would cost about @$2,000.

Cough ... splutter ... gasp, and wheeze. Time for a second quote.

Second sparky turned up this morning. Not only did he put in the 15 Amp circuit on the spot, he used 20 Amp cable because it was a long run. Then he changed the circuits so all other shed outlets were on one circuit (house and shed were together before, now shed has its own circuit breakers), and upgraded the cable from the board to 4.5 mm because of the longish run. Total cost was $630.00.

Let me get this straight
Circuit breaker to shed at main house breaker box.
New 4.5 mm cable.
Shed has it's own set of circuit breakers in shed? (How many?)
If so, $630 is a very good price

OK ...

The house had two power circuits/circuit breakers before today. The meter box is near the front of the house ... the shed is at the back, about 30 M away. The power circuit for the shed also carried some of the house outlets.

Now the house has four power circuits. Two dedicated to the house, and two dedicated to the shed (one is a single 15 Amp outlet and one has four (double) 10 Amp outlets plus one for the garage door).). All circuit breakers are in the main meter box.

The sparky gave me the quote and got the go-ahead. Once he was in the roof space he saw that it would be easy to give the shed its own 10 Amp circuit while he was there. Also, he reckoned that it was a good idea to upgrade the cable for the 10 Amp shed circuit for two reasons. First, it is a long run. Second, it is a warm day and the cabling was warm to touch, and I learned that hot cables carry less current than cool cables. Giving the shed its own 10 Amp circuit and upgrading the main cable for that circuit to 4.5 core was quick and cheap.

Very cheap. The original quote for the 15 Amp circuit was $630. In the end the sparky threw in the additional lump of cable, the extra circuit breaker and a little of his time. Guess who I am calling next time I need a sparky? If you live on the Northside of Brisbane and need a sparky, give me a yell and I will put you in touch with Josh.

The house is only three years old, and the time taken to wire everything in (including circuit breakers) after the cabling was in place was only a few minutes.

Hi John,
You can do it on the cheap, but not too many are in favour of it.
Many moons ago, an old friend bought some S/H Masonite. Attached it to the walls, put a 4in. hole in the top of ea. sheet & blew all his Shavings & Sawdust in, & John that Shed was like Death to walk into.
He wood have machines running, & I was not to far away from his shed & the noise level was almost zero.
Most who are not in favour of this Idea are afraid of fire, but I don't know how it wood catch fire.
His Shed never suffered that Fate.

Originally Posted by John Samuel

OK ...

The house had two power circuits/circuit breakers before today. The meter box is near the front of the house ... the shed is at the back, about 30 M away. The power circuit for the shed also carried some of the house outlets.

Now the house has four power circuits. Two dedicated to the house, and two dedicated to the shed (one is a single 15 Amp outlet and one has four (double) 10 Amp outlets plus one for the garage door).). All circuit breakers are in the main meter box.

OK so there are no circuit breakers in the shed they are back up in the house. Still quite a fair price.

Issatree, the good news is that we can have it all ... very effective dust control and reasonably low noise levels.

My cyclone and BobL's dusty have almost identical noise levels ... around 63dB. Both systems work well and are not noisy.

I am ashamed to say that there is every chance that four months ago my shop was worse than the one you mention; but I am very pleased with the current situation.

David,

Here are two shots of my HVAC ducting ... one from inside and one from outside.

There is a single piece of 8 inch duct the whole way. The 12 inch duct is fitted only to the inside. I pulled two louvres out of the window and fitted clear PVC around the duct to weatherproof the window again.

IMAG0239.jpgIMAG0022.jpg

The two pieces of insulated duct dropped the sound levels from 97 to 66 dB. Given that a 10 dB drop reduces noise by half, that is a big difference. Insulating the blower housing dropped it again to 62-63 dB. At that point, the cyclone was quieter than my shop vac and nearly all my machines. There did not seem to be much point it pursuing it further. In fact I only insulated the blower to see what would happen ... I doubt the time and cost (it was more expensive that the insulated duct) is worth the 3-4 dB reduction.

Hi john Thanks for the extra information. I will let you know how I go sometime next week.

David

Originally Posted by John Samuel

The 12 inch duct is fitted only to the inside. I pulled two louvres out of the window and fitted clear PVC around the duct to weatherproof the window again.

John, is the insulated outlet standard aircon ducting? Guess there is no need for anything heavy duty as it's only fine dust you're having to deal with down the backend.

What thickness PVC did you use? I have a stucco wall and am not wanting to poke a hole through the wall if I don't have to. So I've considered replacing the glass in one window with thick PVC, polycarb or the like and cutting a hole in that. If I used aircon ducting I'd not have to worry about putting too much weight on the window.

Also, what material did you use to cover the impeller housing?

Thanks.