Why on earth are these not the standard for air compressors?
Because air conditioner and refrigeration compressors aren't designed for long time run.
Another thing is that refrigerant helps with lubrication and cooling.
So while pumping air it can work only for short periods of time, much shorter than standard air compressors.
So you shouldn't use this kind of compressors for powering air tools that require a lot of air (hammers, sandblasters, painting guns, wrenches etc.)
But they are perfect for electronics lab shop air.
You don't need much air in electronics lab and this compressors can be used for dusting, paint brush (for fronts panels etc.), or used as air supplies for desoldering stations and paste dispensers.
Its big advantage is that it is very quiet and can be used even in apartments or offices, without neighbours complaining.
I think that you shouldn't go over 120-150 psi.
It's more than enough for regular use, and I think that you don't have knowledge or confidence in tank and compressor itself to use higher pressures.
I'll try to explain how to properly make air compressor for your lab.
DISCLAIMER: Everything you do, you are doing on your own responsibility.
This tutorial contains working with mains wiring and with high pressure. You should have basic knowledge of electricity and pneumatics.
Any mistakes can lead to the electrical shock or explosion with result of injury or death.
Ebay links are here for example only. I'm not in affiliate with any of the sellers. Items are chosen randomly, and they maybe don't have proper pressure ratings.
Double check that all of items have proper pressure ratings needed for your sistem before you buy them. Buy locally if you can and check all details prior buying, ask seller anything that isn't clear for you.You already have compressor and tank, and they are expensive parts of project.
First of all you will need some kind of filter on the compressor inlet so that dust can't get in.
You can use gasoline filter used on motorcycles and lawn mowers.
http://www.ebay.com/itm/3-INDUSTRIAL-HIGH-PERFORMANCE-UNIVERSAL-INLINE-GAS-FUEL-FILTER-5-16-4-L-NEW-/171399419009?pt=Motors_Car_Truck_Parts_Accessories&hash=item27e8339481&vxp=mtrNow we have solved the inlet.
Another thing that we will need is pressure switch. Something like this, they aren't expensive:
http://www.ebay.com/itm/Heavy-Duty-Air-Compressor-Pressure-Switch-Control-Valve-90-PSI-120-PSI-F1-/321453020305?pt=LH_DefaultDomain_0&hash=item4ad817d491Safety valve with proper pressure rating is a M U S T..http://www.ebay.com/itm/1-4-BSPT-Air-Compressor-Pressure-Relief-Valve-Safety-Release-Valves-/360614076885?pt=LH_DefaultDomain_0&hash=item53f64621d5http://www.ebay.com/itm/New-1-4-safety-relief-valve-for-air-compressor-150-psi-/190692710351?pt=LH_DefaultDomain_0&hash=item2c662bd7cfYou should have manometer gauge to control pressure in the tank.
Check valve is highly recommended, it allows easy start for compressor (it will be unloaded).
There are different types of check valves, here is one example.
http://www.ebay.com/sch/i.html?_odkw=check+valve&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR12.TRC2.A0.H0.Xcheck+valve+air+compressor&_nkw=check+valve+air+compressor&_sacat=0Now we covered all things related to the pressure switch.
As you already know compressor is full of oil, and small amount will be sprayed with the air.
We must prevent this for two reasons. First oil must stay in compressor, or it will die. Another reason is that you don't want any oil in your air tools or on the electronics you want clean of dust.
We will use oil/water separator for that purpose.
http://www.ebay.com/itm/TEKTON-4755-Oil-Water-Separator-/221477545760?pt=LH_DefaultDomain_0&hash=item3391172720You must be sure to use separator that have right pressure ratings.
These separators have small valve, so you can return any trapped oil back to the compressor through air inlet (of course you need to remove filter first).
On the output you should have air regulator. They are cheap and come with air pressure gauge and additional separator.
Additional separator is also highly recommended because there will be some condensed water in the tank.
http://www.ebay.com/itm/1-4-Air-Filter-Regulator-Lubricator-Combination-Water-Oil-Separator-AFC-2000-GBW-/151231391994?pt=LH_DefaultDomain_0&hash=item233617e8faYou should put quick air hose couplers after regulator for easy connecting.
This is how you should connect everything.
First you should instal filter on the air inlet.
First thing that goes to the air outlet is w/o separator, then check valve. From there you go to the tank.
If there isn't any convenient place to install safety valve and manometer on the tank you can install them after check valve.
First thing that you should install on the output of the tank is pressure switch. I won't explain how to wire it, or how to adjust pressures. Check your switch manual for that.
Air regulator goes after pressure switch, and then quick coupler is mounted.
Some air tanks have valve at the bottom. It's recommended to open that valve and let condensed water to drain out once a year.