Air compressor-what power?

[bull996]

Thinking of an air compressor-whats the minimum power that needed for all the various air tools?

I think they get measured in CFMs or something.......

[swifthobo]

the minimum is 14 cfm i believe

[cpas]

I'm thinking of buying a car. How fast will I need it?

[tr7v8]

The limitation on a standard 13a socket is 3HP which is around 12-14CFM depending on the accuracy of the measurement. I run air tools on a 2.5HP 9CFM unit & it is OK, you can make it struggle though. Otherwise you'll need a 32Amp circuit wired in by a sparks to run a bigger compressor.

[swifthobo]

my 2.5hp 50 litre struggle's on buzz guns

[swifthobo]

but was thinking make a storage tank

[mrmr96]

cpas said:

I'm thinking of buying a car. How fast will I need it?

To keep up with traffic? About 80-100bhp/tonne.
(It is possible to give a sensible answer if you try.)

[cpas]

mrmr96 said:

cpas said:

I'm thinking of buying a car. How fast will I need it?

To keep up with traffic? About 80-100bhp/tonne.
(It is possible to give a sensible answer if you try.)

I tend to only give sensible answers to sensible questions

[Globs]

bull996 said:

Thinking of an air compressor-whats the minimum power that needed for all the various air tools?

I think they get measured in CFMs or something.......

Go for a twin cylinder belt driven compressor with a tank of at least 80litres.
You will also need a regulator, some piping and fittings, and possibly a dryer.
You will also need an oiler for use with air tools.

[bull996]

Thanks all for the sensible answers-especially about the max for a normal plug.

[cpas]

Most tool manufacturers give a consumption figure for the tool in CFM (cubic feet per minute) and you can limit of choose tool purchase accordingly. Be aware, though, that most compressor manufacturers state the CFM value as air theoretical free air displacement - ie a figure calculated from piston or diaphragm volume and pulses per minute and running with nothing attached to to output. Once running under pressure with a tool attached, this figure goes down to around 2/3 of the stated value. Any compressor will run any tool to a fashion but you may have to pause while pressure builds up. Another thing to consider is the storage tank size as this gives a buffer when using large consumption tools. As stated before, a 3hp motor is about the max from a 13A supply, and this can produce about 14CFM - in fact Machine Mart/Clarke do one which does all this for £300 (Airmaster 14/60) and I've had a similar one for about 20 years now.

[cpas]

(See, I can do sensible)

[King Herald]

bull996 said:

Thinking of an air compressor-whats the minimum power that needed for all the various air tools?

I think they get measured in CFMs or something.......

Buy the biggest one that comes with a 13 amp plug. It will be just about adequate for most home-use air-tools.

You'll probably find that you need to pause quite often to allow pressure to build up again with some tools. Especially if you use a spray gun.

I added a 'storage tank' to mine, just an old LPG tank plumbed in parallel. It gives you a bigger reserve, a buffer, so you can do longer runs with a particularly greedy air-tool.

[MDT]

A few things to keep in mind.

The small direct driven units are quite (well very) loud. The belt driven units are far quieter.

To run the tools which demand larger volumes of air you will need to use 10mm air lines as the smaller 8mm ones just cant flow enough.

If you go for a larger belt driven unit you will likely need to buy a regulator and a water separator is a good idea too.

I have one of these in the garage http://www.machinemart.co.uk/shop/product/details/... hard wired in to the house supply. The lights do dim when it starts up but with the rubber feet fitted and behind a ply wood sheet it is actually quite quiet and it is not a problem running it for an extended time, when shot blasting say.

[krusty]

I've one of these
http://www.machinemart.co.uk/shop/product/details/...

and it's been fine for everything I've wanted to do. The guy in machine mart said that you need at least a 50ltr tank to run air tools

[Mark Benson]

krusty said:

I've one of these
http://www.machinemart.co.uk/shop/product/details/...

and it's been fine for everything I've wanted to do. The guy in machine mart said that you need at least a 50ltr tank to run air tools

In my experience, the bigger the tank the better. Since the limit for a householder is the 13amp plug, the next best thing is to have as big a reserve as possible.

The other question you need to ask yourself is what tools do you plan to run?
If you require short bursts (air-riveter or cut-off tool for example), a smaller compressor and tank will probably do, if you need long, continuous running (sprayer, nibblers etc.) then you want all the capacity you can get.

[Globs]

MDT said:

The small direct driven units are quite (well very) loud. The belt driven units are far quieter.

Deafening in a really crap kind of way yes.

Mark Benson said:

In my experience, the bigger the tank the better. Since the limit for a householder is the 13amp plug, the next best thing is to have as big a reserve as possible.

This is why I recommended a twin cylinder. This gives two stage compression which apart from being quieter gives far higher pressure, 140lb/in easily - which makes your tank go further because it pushes more air into it!

Regulating down from 140lb to 100lb for air tools gives a nice 40lb buffer, the compressor only needs to run occasionally.

[King Herald]

I remember fondly the day my 14cfm compressor arrived, bought off a buddy. It were grand fun getting it out to the 'shop, then up into the loft.....





Once up there I fitted some rubber mounts, made from heavy duty 3 inch rubber hose. You'd hardly know it was running once the loft hatch was closed, and it was man enough to spray a car body with without running down.

[G600]

Globs said:

You will also need an oiler for use with air tools.

Really? We use dry air where I work, the same supply as the sprayers use, and there's guys with 20+ year old tools that just get an occasional drop of oil.