Air Compressor for home garage

[Shane911]

Not sure if this is the right place to post this question but here goes anyway.

I am looking to buy an air compressor for my garage, it will get very little use, the only reason I am looking to buy one at the moment is so that I can vacuum test and then fill the coolant system in my 2001 996 C2.  What size air compressor do I need for that?  and what are the figures/statistics that are import?  Horse Power, Max PSI, Litres per minute?

Once I have one I am sure I will find other uses for it but am also conscious of size and space requirements, I don't want a huge air compressor taking up valuable space in my garage.

All thoughts would be appreciated (SCA have a good deal on a Stanley Air Compressor at the moment but might be more than I need)

Also just while at it, when watching Youtube videos of how to carry out this task they all talk about removing the Secondary Air Pump but my car doesn't have one and all the time it has been serviced by Porsche no one has mentioned that it is missing.  Is this just a US anti pollution requirement or something?  Do other Australian owners have a Secondary Air pump on their cars. (I can see the screw holes in my car where it should sit)

 

Thanks

 

[st3ve]

Secondary Air Injection is not on the Aus market cars, so one less thing to worry about.

Regarding air compressors, I've bought an airlift coolant system but have also not yet used it, so I can't comment on what it requires yet from experience.  It's blowing air past a venturi as a crude form of vacuum pump, so actually it likely consumes a reasonable amount of air.  But you won't need to use it often, and can pump down in stages, letting the compressor recover each time.  So for occasional use a smaller compressor - even a battery one - is possibly better for you so you don't have this lump in your way all the time.

Also, the usefulness of air in a workshop has changed a lot in recent years with the rise of cordless electric tools.  So the other tasks you might have found to make use of a bigger compressor (rattle gun, tyre inflator, die grinder, pop rivetter, etc) are often better served these days by battery tools.  Do you have any battery system tools already?

Having said all that, I looked at SCA site and see the one you're talking about, that looks like great bang for bucks.  I bought a Stanley one from SCA and scary to think but it's probably 15 years old now, hasn't skipped a beat.  Mine is of similar capacity but of the older and noisier belt drive twin cylinder piston type, noise is a major pain when using compressed air so the quieter the better.  My highest air-use tool is a soda blaster which operates on a kinda similar principle to the airlift venturi pump.  The soda blaster will max out my compressor but it's entirely useable for decent periods.  I'm pretty sure an airlift coolant tool would be perfectly useable on a much smaller machine given a little patience.

[Carrera28]

If I was buying one for a home garage I would consider this:

https://sydneytools.com.au/product/milwaukee-m18fac0-18v-liion-cordless-fuel-76l-90psi-air-compressor-skin-only

[luzzo]

11 hours ago, st3ve said:

noise is a major pain when using compressed air so the quieter the better.

Noise was one of my main concerns when buying. Mine is just for home garage use, so large capacity for hungry air tools and max psi was not main issue. 

Operates at 42db.

https://sydneytools.com.au/product/chicago-hush20-aluminium-silenced-20l-air-compressor 

 

[Carrera28]

The Milwaukee one that I mentioned runs at 68db which is about the same as conversation and is quieter then a vacuum cleaner.

https://ehs.yale.edu/sites/default/files/files/decibel-level-chart.pdf

[Peter M]

15 hours ago, Shane911 said:

I am looking to buy an air compressor for my garage, it will get very little use, the only reason I am looking to buy one at the moment is so that I can vacuum test and then fill the coolant system in my 2001 996 C2.  What size air compressor do I need for that?  and what are the figures/statistics that are import?  Horse Power, Max PSI, Litres per minute?

Shane,

To avoid wasting money and disappointment you need to figure out how much air you need to drive the vacuum pump.

Is this the type of pump you are looking at: 4.2CFM Operated Air Vacuum Pump Air Conditioner Auto Tool Pneumatic Vacuum Pump | eBay

If this is the case you need a compressor that can deliver = 4.2/0.7 (allowance for duty cycle so it doesn't run continuously and can cool down occasionally) = 6 cfm FAD (Free Air Delivery)

Just be aware that compressor manufacturers advertise both pump displacement and FAD, which are very different and this can get confusing.  Stick with FAD and you can't go wrong.

The Stanley one on sale looks pretty good at $399 for 210 litres per minute FAD and possibly plenty large enough since 210 LPM = 7.4 CFM.  Importantly it looks reasonably quiet too.

Stanley Air Compressor Silenced 2.75HP 50 Litre tank | Supercheap Auto

 

As an alternative you can buy vacuum pumps for about a third the cost of this compressor and vacuum pump attachment that will do a much better job of pulling a vacuum.  However I don't actually know what you are doing to your cooling system so can't really recommend either way.

Hope this helps!

[Shane911]

Thank you all for your help.

@ st3ve I have also purchased the Schwaben Coolant refill and air extraction kit but haven't used it yet (as I need a air compressor). I did reach out to one of the Youtubers that ran a demonstration of using this tool and they said you need a compressor capable of delivering at least 90 psi for it to work properly.  Yes I agree with your thoughts on the use of air tools and yes I have a lot of cordless tools (Ryobi) including an impact wrench, drills, etc and find them really convenient and easy to use. (not sure how long they will last but they don't get a great deal of use, so are okay for my purposes)

 

@luzzo and Carrera28 I like the size of those models but a bit pricey for my needs.  

I don't really need an air compressor (or the coolant refill and extraction tool) other than for this task but with the price Porsche wanted to charge me for doing this, I can buy the Air compressor and all tools and the parts and still have money left in my pocket.

@PeterM I am replacing the the Coolant Reservoir so need to drain and then refill the coolant system. Do you have any recommendations on a vacuum pump?

 

 

[Shane911]

Also PeterM this is the coolant refill and air extraction tool that I have purchased

and a video of how they work

 

https://www.amazon.com.au/gp/product/B01BW39HJS/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

And I found out that it needs at least 90PSI

[slknv]

I had an old blackridge cheapie from SCA from years ago, and it worked fine to vacuum refill my 996. Also useful for a bunch of other jobs eg impact wrench, tyre inflation, and I even painted my S15 bodykit with it too (with a bunch of water traps and air pressure regulators), but it's a noisy bugger and small air capacity. More than enough to draw a simple vacuum.