Need quiet 240v 14 cfm FAD @ 8 bar compressor. Options?

[flanajb]

Morning all,

I have been looking into this one and am struggling to come up with a solution. Piston compressors will give me the FAD, but they are too noisy and I need something < 70db. I have seen a 240v screw compressor, but the FAD is around 12 CFM.

The other option is whether I could purchase a 3 phase screw compressor, something around 5.5kw and run it off a single to 3 phase inverter? Just not sure whether compressors are suited to running off an inverter.

Thanks

 

[rtbcomp]

Most people get round the problem by installing the compressor in a soundproofed housing, but this brings its own problems.

You could try fitting a silencer on the inlet, quite a lot noise comes from there.

I've extended my inlet with a length of vacuum cleaner hose and put the end in a filing cabinet drawer, that made a noticeable difference.

I've also seen a car exhaust box fitted to a compressor.

If you do fit anything to the inlet, make sure it's perfectly clean though.

 

[CompoSimmonite]

What about two smaller compressors ?

 

[flanajb]

Most people get round the problem by installing the compressor in a soundproofed housing, but this brings its own problems.

You could try fitting a silencer on the inlet, quite a lot noise comes from there.

I've extended my inlet with a length of vacuum cleaner hose and put the end in a filing cabinet drawer, that made a noticeable difference.

I've also seen a car exhaust box fitted to a compressor.

If you do fit anything to the inlet, make sure it's perfectly clean though.

With the changes you have made are you able to have a conversation next to the compressor or is it still too loud for that? Just keen to understand how much of a db reduction you managed to achieve?

 

[rtbcomp]

With the changes you have made are you able to have a conversation next to the compressor...

Probably not, though I've never tried, (It's situated in the loo and I only go in there by myself) but you can hear a difference in sound level when you open & close the cabinet drawer.

 

[HughF]

Compressor on vfd is fine, wire the pressure switch to the control terminals...

Hydrovane 15 would be a good option for your air/noise requirements.

 

[flanajb]

Having researched 240v options I have concluded that a single phase unit will not provide the required FAD. Anyone know whether I can use an inverter to run a 5.5hp 3 phase compressor from 240v?

The unit I am looking at https://www.machinemart.co.uk/shop/product/details/clarke-sse25c270-5-5hp-270ltr-low-noise-recipr

 

[brightspark]

Having researched 240v options I have concluded that a single phase unit will not provide the required FAD. Anyone know whether I can use an inverter to run a 5.5hp 3 phase compressor from 240v?

The unit I am looking at https://www.machinemart.co.uk/shop/product/details/clarke-sse25c270-5-5hp-270ltr-low-noise-recipr

Having researched 240v options I have concluded that a single phase unit will not provide the required FAD. Anyone know whether I can use an inverter to run a 5.5hp 3 phase compressor from 240v?

The unit I am looking at https://www.machinemart.co.uk/shop/product/details/clarke-sse25c270-5-5hp-270ltr-low-noise-recipr

why dont u ring clarke up or a supplier of converters and get the proper advise . its a lot of money to take a gamble on

 

[CompoSimmonite]

Have you considered simply having 3 phase supply installed ? Could work out cheaper in the long run than an inverter.

 

[HughF]

Having researched 240v options I have concluded that a single phase unit will not provide the required FAD. Anyone know whether I can use an inverter to run a 5.5hp 3 phase compressor from 240v?

Yes, buy a big enough VFD and wire the pressure switch to the control logic...

 

[MattH]

Having researched 240v options I have concluded that a single phase unit will not provide the required FAD. Anyone know whether I can use an inverter to run a 5.5hp 3 phase compressor from 240v?

The unit I am looking at https://www.machinemart.co.uk/shop/product/details/clarke-sse25c270-5-5hp-270ltr-low-noise-recipr

A suitable VFD for that job is going to cost you around £1000. You'd be better off buying two 3hp single phase belt driven units and combining the output to get the CFM you want.

 

[HughF]

7.5kw chinese vfd, £179 quid delivered off ebay... Granted that is 240-240 not 240-415, re-wirable motor required.

 

[MattH]

I was under the impression that the big Hyanyang VFD's needed three phase input?

I wouldn't think that 7.5kw would be enough for a 5.5kw comp.
I'd be looking in the 15kw range to handle startup current.

 

[octo0072000]

this any good single phase sorry no noise figures plenty of air though

https://www.machinemart.co.uk/shop/product/details/se29d270-ol-air-compressor

 

[HughF]

I was under the impression that the big Hyanyang VFD's needed three phase input?

I wouldn't think that 7.5kw would be enough for a 5.5kw comp.
I'd be looking in the 15kw range to handle startup current.

According to the chinglish ebay add, it's single phase or 3 phase (not much help, that)...

My experience of compressor pumps off vfd's is that provided the ramp up time is kept fairly sensible and the unloader works properly, you can size the vfd directly to the motor - startup current isn't a problem.

 

[MattH]

Looking at them they need 380v though.

 

[Mr shiney]

My Hydrovane delivers that no problem on single phase and is quiet enoug to talk next to easily when running. I have it running a 300l receiver along with the 250l built in one.

 

[addjunkie]

You could used a heavy duty phase convertor on a compressor, old tech, but you wouldnt have to mess about with the controls assuming any realys, cut outs etc come from l1 and l3.

Vfd wind speed up and down a compressors stops and starts. Some reading below...
.
http://www.powercapacitors.co.uk/products/transwave-converters/transwave-converters/

 

[HughF]

Hydrovane single phase as has been mentioned before.

 

[flanajb]

Thanks for your posts here. A standard piston compressor running at +90db is a non starter. Both from a neighbor perspective and for my own sanity. It's far too loud.

A number of people have posted that their hydrovane compressors on single phase will handle 12cfm at 7 bar. Please send me a link to such units as the 3hp hydrovanes I have seen all state 8cfm FAD.

I have exhausted all options and the only unit I have found to date that will give me a quiet unit and required CFM is a 4hp screw compressor

http://www.ebay.co.uk/itm/Quiet-220...ice-Support-/121768982776?hash=item1c59ff38f8

I am amazed that no company makes a low noise 4hp piston compressor. You can get a 3hp one, but not 4hp.

I am not sure the screw compressor is the right thing though as the unit will be used very stop start and for short periods.

Budget for this is 1K