Noise Insulation for shop compressor?

[Doofy]

Still about 2 times more than I would spend. If trying to make a living with it, maybe.

 

[ruffdog]

Still about 2 times more than I would spend. If trying to make a living with it, maybe.

I know what you mean. At one time, I had a use for all my air tools and spray guns. Now, I use air to blow off the mower and fill tires.

 

[Doofy]

I know what you mean. At one time, I had a use for all my air tools and spray guns. Now, I use air to blow off the mower and fill tires.

I also wonder about the longevity of aluminum pumps vs the venerable cast iron pumps?

 

[TMGT]

I get the log scale for dB and that is a huge drop, but honestly I don't have a clue what 5x means in terms of audible sound. Need to hear it side by side.

Worth it... nope. Got other tools I 'need' first. Time to get on with the design of the outhouse for the compressor. Doghouse is covered... that is my shop. Recently plumbed for a sink and small fridge, just need a foldable cot. :laughing:

My large screw compressor is rated at 70dba, I can say it is just a hum in the distance, especially compared to my standard 7.5ho 2 stage reciprocating compressor. I couldn't find the dba rating on it but i imagine it would be close to yours. I imagine 75dba would be pretty tolerable.

 

[dragoneggs]

Would this one for $1400 shipped be ok?

California Air Tools CAT-60040CAD 60040CAD Ultra Quiet & Oil-Free 4-HP 60-Gallon Steel Tank Air Compressor w/ Auto Drain

Any idea of the difference between this one and the $3500 unit? I haven't matched up the specs.

 

[dragoneggs]

Okay a bit deeper dive into my Husky 3.7hp 60gal compressor...

Pulleys
Motor = 4in
Compressor 12in
Centers 10in

Motor = 3450rpm
Compressor = 1150rpm

View attachment 667348

Compressor is mounted on double sheet of 3/4in plywood and HF 3in polyurethane casters.

Noise (pretty much against wall)

88dB @3ft
85dB @6ft

Noise (compressor 3ft from wall and rotated 90deg so front/back not facing wall)

86dB @3ft
83dB @6ft

Compressor intake on top with filter on side. 2 intake ports about 1.25in by .5in (a little smaller but couldn't fit my calipers)

View attachment 667351 View attachment 667352

Checked noise to compare with OEM intake filter on/off:

Noise (compressor 3ft from wall and filter ON)

86dB @3ft
83dB @6ft

Noise (compressor 3ft from wall and filter OFF)

88dB @3ft
85dB @6ft

 

[ray66v]

I also wonder about the longevity of aluminum pumps vs the venerable cast iron pumps?

Though everyone seems to agree a cast iron pump is quieter and would last longer, my home compressor is a Campbell Hausfeld V-twin, it's belt driven with an aluminum pump, 30 gallon tank, and a true 4hp motor.

It was not cheap, ($780, in 1984). But, it was a light commercial grade unit, and it's the quietest compressor I have ever heard.

This compressor has a lot of hours on it, many of them hard hours. And, the aluminum pump has never needed any repair.

If you consider the reality that the tank has reached the limits of it's useful life, the pump has effectively out lasted it.

I have owned both cast iron, and aluminum compressors commercially as well, and I do not consider an aluminum pump a liability.

 

[Doofy]

Though everyone seems to agree a cast iron pump is quieter and would last longer, my home compressor is a Campbell Hausfeld V-twin, it's belt driven with an aluminum pump, 30 gallon tank, and a true 4hp motor.

It was not cheap, ($780, in 1984). But, it was a light commercial grade unit, and it's the quietest compressor I have ever heard.

This compressor has a lot of hours on it, many of them hard hours. And, the aluminum pump has never needed any repair.

If you consider the reality that the tank has reached the limits of it's useful life, the pump has effectively out lasted it.

I have owned both cast iron, and aluminum compressors commercially as well, and I do not consider an aluminum pump a liability.

Good to know. Thanks

 

[pmsmechanic]

There is also the possibility that the aluminum compressor has a cast sleeve for the piston to run in.

 

[dragoneggs]

I just ordered 12sq ft (1ft squares) of insulation panel. Will experiment with them in the compressor's current indoor spot and see if they are effective. If not, I have another project that I can use the insulation.

Speaking of noise insulation... the dang squirrels are waking us up in the early mornings. They are picking and dropping (intentionally throwing) green pine cones on our roof above the bedroom. They are about to be served a 22 pill.

 

[Doofy]

Also, air compressor manufacturers have been caught stretching the truth. My Cambell Hausfeld 6 Horsepower / 60 Gallon compressor is actually only 3.4 Horsepower. Beware of Lies!

 

[dragoneggs]

Also, air compressor manufacturers have been caught stretching the truth. My Cambell Hausfeld 6 Horsepower / 60 Gallon compressor is actually only 3.4 Horsepower. Beware of Lies!

Yep... look at Volts x amps/745 for more accurate Hp number.

 

[Doofy]

Companies sure know how to troll for Suckers. Sears also nailed me on a 6hp Shop Vac about 20 years ago. It couldn't have been over a 1hp. Still using it with a "Dust Deputy" in the garage.

 

[radios1]

Companies sure know how to troll for Suckers. Sears also nailed me on a 6hp Shop Vac about 20 years ago. It couldn't have been over a 1hp. Still using it with a "Dust Deputy" in the garage.

it was probably 6HP. PEAK. NOT Average.. like when the motor is stopped very quickly after it gets to full speed!..

 

[BukitCase]

" look at Volts x amps/745 for more accurate Hp number"

Mark, a MINOR "nit pick" - 1 electrical horsepower is 745.7 watts :laughing:

Also, using that formula only tells you how much horsepower you're INPUTTING; one example - the 5 horse industrial compressor I linked to previously in this thread, uses 21.5 amps @ 240 volts: so it's INPUT power works out to just over 6.9 horsepower. Works out to just over 72% efficiency, IF that Baldor motor's only putting out a REAL 5 horsepower.

And no, I'm NOT gonna hook it up to a rope/pulley/weight and see if it can lift a 550 lb weight more than 5 feet per second :laughing:

Attention Required! | Cloudflare

radios1 - I've seen little 120 volt vertical "roll-around" compressors marked 6 horsepower; pretty sure they used locked rotor amps to calculate THAT lie ... Steve

 

[ovrszd]

Kinda like small fuel engines.

 

[BukitCase]

Yup; one of my old man's favorite sayings was "figures don't lie- but a liar can figure..." ... Steve

 

[radios1]

" look at Volts x amps/745 for more accurate Hp number"

Mark, a MINOR "nit pick" - 1 electrical horsepower is 745.7 watts :laughing:

Also, using that formula only tells you how much horsepower you're INPUTTING; one example - the 5 horse industrial compressor I linked to previously in this thread, uses 21.5 amps @ 240 volts: so it's INPUT power works out to just over 6.9 horsepower. Works out to just over 72% efficiency, IF that Baldor motor's only putting out a REAL 5 horsepower.

And no, I'm NOT gonna hook it up to a rope/pulley/weight and see if it can lift a 550 lb weight more than 5 feet per second :laughing:

Attention Required! | Cloudflare

radios1 - I've seen little 120 volt vertical "roll-around" compressors marked 6 horsepower; pretty sure they used locked rotor amps to calculate THAT lie ... Steve

if someone wants to calculate the kinetic energy of a motor running a 3450 rpm and has a 10 lb. rotor, here's the formula.. Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared. Kinetic energy is usually measured in units of Joules (J); one Joule is equal to 1 kg m2 / s2.

 

[dragoneggs]

" look at Volts x amps/745 for more accurate Hp number"

Mark, a MINOR "nit pick" - 1 electrical horsepower is 745.7 watts :laughing:

Also, using that formula only tells you how much horsepower you're INPUTTING; one example - the 5 horse industrial compressor I linked to previously in this thread, uses 21.5 amps @ 240 volts: so it's INPUT power works out to just over 6.9 horsepower. Works out to just over 72% efficiency, IF that Baldor motor's only putting out a REAL 5 horsepower.

And no, I'm NOT gonna hook it up to a rope/pulley/weight and see if it can lift a 550 lb weight more than 5 feet per second :laughing:

Attention Required! | Cloudflare

radios1 - I've seen little 120 volt vertical "roll-around" compressors marked 6 horsepower; pretty sure they used locked rotor amps to calculate THAT lie ... Steve

if someone wants to calculate the kinetic energy of a motor running a 3450 rpm and has a 10 lb. rotor, here's the formula.. Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared. Kinetic energy is usually measured in units of Joules (J); one Joule is equal to 1 kg m2 / s2.

Yep all good stuff guys... thanks for adding additional 'noise' here. :laughing:

 

[dstig1]

So I looked into mine a bit more. Here it is with a look at the air intake. There is a pleated paper element like an old style car engine air filter and a tube sticking up inside the housing for some reason. This doesn't look far off what the "mufflers" that you see from a web search show.







Then I used an app to measure the sound level via my phone. It averaged out around 68.5 dB at ~3'. But yet it seems louder than that to me. I'm not sure if this thing is at all calibrated, so maybe I will check it vs a sound meter we have at work. But if that is correct, then you guys with the 80+dB compressors must be in a world of hurt!