Compressor size question

[AK Caster]

I am considering buying a compressor for my workshop. Currently do not own any air tools but would get an impact wrench for rotating tires, etc. and other common uses such as tire inflation. I do not do anything on the commercial level and only use the workshop on occasion. Might buy another air tool or two down the road but none would be used for extended times.
What size compressor can I can by with?

[farmerjim]

If it is just for intermittent use of low consumption air tools, a one cylinder 2 hp with a 20 gal tank will work. If it is for moderate use of the higher consumption tools. go for a 2 cylinder 5 hp, 30 gal tank minimum.

[smoked turkey]

These are big "ifs", but if your electrical panel has room for a 240 VAC breaker, I recommend you purchase a unit that can be wired for 240 vac. Get plenty of air hose for those long runs or even better plumb your shop with pipe for quick release fittings at various places where you anticipate needing compressed air. I confess that I have not plumbed my shop, but wish I had.

[Three44s]

Air is pretty inefficient. You figure a reasonable size and then size up! Otherwise you will be waiting for it to build up long and often.

There is a reason that compressor prices shoot up exponentially as you size up.

Three44s

[AK Caster]

These are big "ifs", but if your electrical panel has room for a 240 VAC breaker, I recommend you purchase a unit that can be wired for 240 vac. Get plenty of air hose for those long runs or even better plumb your shop with pipe for quick release fittings at various places where you anticipate needing compressed air. I confess that I have not plumbed my shop, but wish I had.

Way overkill for my use. Shop is 32x32 so can get by with a "worse case" hose length of 30 feet. Only one workbench and one vehicle at a time for tire rotating.

[rockrat]

Mine is the 5 hp 2 cyl and my shop is is 30 x 35. The idea of plumbing the shop is a good one. Wish I had done that before I filled it with ju-- err stuff.

[frkelly74]

Well, I opted for a portable compressor because I did not want to plumb the shop and also I wanted to be able to transport the compressor easily. The pancake units that harbor freight sells for about $100, when they are on sale, put out enough air to run a nail gun or maybe two, and if you get to nailing sheathing on a roof that can take a lot of air. (Get the replacement warranty, it is pretty cheap.) This is not the smallest one that they sell for $40 on sale, but the bigger one that you can still move around pretty easily. I opted for an electric impact wrench for my tire rotations and other high torque chores.

[jcren]

The classic belt driven, 2 cylinder 5 hp/20+ gallon has long been the standard for farm and general shop use. Should be able to get a good one for around $350. Don't get too hung up on brand, pay attention to pump contruction (cast iron, copper finned transfer line, oil lubed) and overall build quality. We sold Coleman, Cambell Hausfeild (sp), DeWalt and others. It was surprising how often the actual pump would be identical but on a different style/color tank and different belt guard for $50-$100 difference in price. Also, stay away from air-up tires on your ompressor. Nothing worse than having to fix a flat on your compressor before you can air up a tire!

Btw, for the convenience of a plumbed shop, just go ahead and run 3/4" pvc with female couplers where you want to be able to tap in and a male coupling on a short whip hose where you plan to park your potrtable compressor. Plug the short hose into the compressor at the regulator for stationary compressor shop use , unplug it and use your regular 50' hose for portability.

[472x1B/A]

Way overkill for my use. Shop is 32x32 so can get by with a "worse case" hose length of 30 feet. Only one workbench and one vehicle at a time for tire rotating.

With a 32x32 garage, 'way over kill for my use' not really. WAY back when, in my 24x24 garage, I had an Ingersoll-Rand 80 gal., upright, 240vac. compressor. Want to kick myself every day for selling it, but was in need of $$$. Really do your home work on sizes and future needs. Be live me, you my regret later not getting something just a little bigger than what you think you need right now. Also go with an inline filter/oiler, another added benefit to your tools.

[country gent]

Ideally for a shop area garage put the compressor out side in its own little "room" with screened wall or louvered wall. and plum the air inside with a switch on the wall to turn on and off.The advantages are compressor runs cooler and thus longer, The running compressor is outside away from you making for a quieter shop. The pipe used for plumbing the line adds 2 the air capacity of the tank increasing the supply available, a 2" line 20-30' long holds a lot of air.
If you go for the plumbed air lines bring the drops off the top of the main, this keeps condensation out of the air lines better. And a drop off the bottom to floor level along one wall to drain condensate of into a bucket. A tee in the line up and 2"-1/2 or 3/4" reducer bushing, close nipple 90* elbow 2" nipple and 90* elbow then the length of pipe down required to put the quick couples at the right height for the area. A couple drops over the bench is very handy.
As to air tools a couple die grinders in different sizes, impact driver, air ratchet, tire chuck and blow gun cover a lot.

[waksupi]

For needs like yours, a small contractor compressor is plenty. If you ever want to run a sand blaster, you are going to need pretty large capacity.

[JonB_in_Glencoe]

Air impact wrenches have different efficiencies. I have a few of them, a couple of the cheap HF units will drain my small tank quickly, but the newest unit I got from HF is a better more efficient high torque design and doesn't use near as much air.

I could explain my situation exactly like the OP's predicted situation, I've always wanted a larger air compressor, but for 20+ years I've gotten by with a homemade air compressor with a real old 3/4 electric motor on a 15 gallon homemade tank...I don't know what size the belt driven air unit is?

[gpidaho]

The electric impact wrench is good advice. Compressors are a go big or go home sort of deal and for the price you'd be far better off having the tire shop handle your rotations. Gp

[lefty o]

if all your ever going to do is use an impact to change tires, you do not need a lot of compressor. a medium small 110v with a 20-30gal tank is plenty. where you need to be concerned is doing a lot of non stop work, or using air sanders, paint guns, sandblasters, those all use large quantities of air.

[AK Caster]

I tried a new electric Dewalt impact. It would not loosen the lug nuts on my Ford truck and Expedition. Dewalt was rated at like 370 foot pounds. Lugs were torqued to 150, figure that one out.

[MT Gianni]

I had no problems with Dewalts electric impacts. I ran 18 Volt tools then went to 20 V when I worked full time. Most were used to break down pipe flanges but also assisted folks with flats. Out of probably 12 tire changes there was one I needed to put a breaker bar on. At 150 ft lbs your lugs had been overtightened, AK Caster.

[AK Caster]

I had no problems with Dewalts electric impacts. I ran 18 Volt tools then went to 20 V when I worked full time. Most were used to break down pipe flanges but also assisted folks with flats. Out of probably 12 tire changes there was one I needed to put a breaker bar on. At 150 ft lbs your lugs had been overtightened, AK Caster.

Not true. Owners manual calls for 150 ft pounds for both.

[fecmech]

Look for the output capacity of the compressor. I have about a $300. Craftsmen compressor that puts out 7 cf/min@90 psi. It runs my 1/2" impact just fine for tire changing and I used it to remove all the mortar in my stone house using the air chisel. I don't have to wait for it to build up at all. I believe something like that would be more than adequate for your use.

[bangerjim]

Most normal air tools call for at least 90-100 PSI and anywhere from 2 to 8 CFM.....something a small little pancake direct drive unit will NOT do.

I have 4 different sizes of compressors for my needs:

For pumping up tires and small tools a compact pancake direct a drive unit will work. I have one in my small model/casting shop and it works well for the ESPC guns. But it cycles a lot!!!!!!!!! And is noisy as heck, being direct drive. Belt drives, like on table saws, are much quieter!!!!!!!

For my big shop I have a 100 gallon 10HP 2 lung 220V big boy that will handle anything I hook up to it!!! But is cost 7X what the little pancake unit did.

Figure your FUTURE needs and buy accordingly. Also the hoses you want/need to be the largest you can find/afford. Running tools on a 1/4” ID coiled plastic *** (HF) will never work for most people. And invest in good quality quick connects!

[EDG]

Just look up the CFM requirement for the tool that uses the most air and compare to the capacity of the compressor.