Air Compressor Selection

For your needs, a belt drive, twin cylinder, 20 gallon 115V compressor will do just fine. I despise oil-less compressors. They don't last and they are often objectionably noisy, despite claims to the contrary. A couple of good choices:

https://www.northerntool.com/shop/tools/product_200375221_200375221

[Linked Image from aircompressorsdirect.com]
 
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Originally Posted by samven
The Kobalt wont run on your circuit. It says 15A@230V what it does not say is it will draw 30A@115V and even with a 30A breaker it will probably trip the breaker when restarting at 100+ PSI.


Compressors have Unloaders & a Tank Check Valve so the Motor "Start" Amperage doesn't vary much at all between a pressurized vessel & unpressurized vessel.
 
Originally Posted by hatt
The Kobalt will run on a normal 120 15A circuit. Goodness, the stuff you read around here sometimes.


I read the same specs he did......15A @ 240vac, So the assumption that it will draw 30A @ 120vac isn't far fetched at all.

The ancient 20 gallon compressor in my home garage has a dual voltage 1.5hp Dayton motor rated 22A @ 115vac & 11A @ 230.....It would blow a 20A breaker intermittently upon start-up on 120vac especially at cold temps. Rewired it with a dual pole 20A breaker & 240vac....Working great for the past 15 years.

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]
 
Originally Posted by clinebarger
Originally Posted by samven
The Kobalt wont run on your circuit. It says 15A@230V what it does not say is it will draw 30A@115V and even with a 30A breaker it will probably trip the breaker when restarting at 100+ PSI.


Compressors have Unloaders & a Tank Check Valve so the Motor "Start" Amperage doesn't vary much at all between a pressurized vessel & unpressurized vessel.

The spec sheet he put up says 15A at 230V but is rewirable to 115V. They dont say it takes 2x the current which it will and he wants to run on a 20A ckt. Even if it draws less than spec it will still trip his 20A breaker.
 
Originally Posted by samven
Originally Posted by clinebarger
Originally Posted by samven
The Kobalt wont run on your circuit. It says 15A@230V what it does not say is it will draw 30A@115V and even with a 30A breaker it will probably trip the breaker when restarting at 100+ PSI.


Compressors have Unloaders & a Tank Check Valve so the Motor "Start" Amperage doesn't vary much at all between a pressurized vessel & unpressurized vessel.

The spec sheet he put up says 15A at 230V but is rewirable to 115V. They dont say it takes 2x the current which it will and he wants to run on a 20A ckt. Even if it draws less than spec it will still trip his 20A breaker.


The spec sheet is wrong its 15amps at 115v

The HF model I listed with a similar output and motor is 13.8amps@120v
 
Originally Posted by samven
Originally Posted by clinebarger
Originally Posted by samven
The Kobalt wont run on your circuit. It says 15A@230V what it does not say is it will draw 30A@115V and even with a 30A breaker it will probably trip the breaker when restarting at 100+ PSI.


Compressors have Unloaders & a Tank Check Valve so the Motor "Start" Amperage doesn't vary much at all between a pressurized vessel & unpressurized vessel.

The spec sheet he put up says 15A at 230V but is rewirable to 115V. They dont say it takes 2x the current which it will and he wants to run on a 20A ckt. Even if it draws less than spec it will still trip his 20A breaker.


Read the post above....
 
could also run 230 to the garage are you going to want to plug in an electric car or hybrid in the future?
 
Originally Posted by clinebarger
Originally Posted by hatt
The Kobalt will run on a normal 120 15A circuit. Goodness, the stuff you read around here sometimes.


I read the same specs he did......15A @ 240vac, So the assumption that it will draw 30A @ 120vac isn't far fetched at all.

The ancient 20 gallon compressor in my home garage has a dual voltage 1.5hp Dayton motor rated 22A @ 115vac & 11A @ 230.....It would blow a 20A breaker intermittently upon start-up on 120vac especially at cold temps. Rewired it with a dual pole 20A breaker & 240vac....Working great for the past 15 years.


Someone in the reviews posted this from the machine.
[Linked Image]


We know that's the 120 amperage rating because how many people have 30A 120v circuits. They'd have returned machines all over the store.
 
Late to the party, but I'll throw my two cents into this.

I know it might get laughed or scoffed at, but I've had my 21 Gallon unit from Harbor Freight for two years now and it has been flawless. Broke it in according to the manual and have been using it since. Usually use it to blow the grass off my mower once a week, but has been used several times with a HVLP spray gun for home improvement projects and didn't skip a beat. It also recently powers my Earthquake XT 1/2" stubby air impact. Had enough oomph to bust the 35mm front CV axle nut off my Tacoma, now this was after several tries and cycles, but that could have been due to the previous guy working on it. Works quite well for wheel swaps. I swapped wheels a couple weeks ago and it only cycled a couple times for all 4 wheels. I've been impressed with it. I have it stationary in the garage hooked up to my hose reel. Also have a water/oil separator on it. It is a little loud, but it might be a matter of opinion. I would buy another one. I only have a 20 amp circuit in my garage and haven't had an issue with it running while my lights, radio, and even work light are on at the same time. For a low use compressor this might suit your needs and at $150 it won't break the bank!
 
As usual, thanks for all of the feedback. Just a few general thoughts:

1) Chances are, most of these options are borderline overkill for my purposes.

2) In general, Kobalt items seem to be dwindling at local Lowe's stores. Rumor is that they are slowly being replaced by more Craftsman. If this is true, perhaps that is a long-term consideration.

3) The newest oil-free compressors (especially the HF 27 gal fortress) seem to deliver superior output and noise specs than the oiled models. I know that oiled compressors are supposed to be superior, but for light-duty applications, is it possible that the newest oil-free are superior for my purposes?

4) It appears that the Dewalt/Husky compressors are very similar (even down to the same Assembled in USA stamp) while the Kobalt models are different. Who is supplying the compressors to these big-name brands?
 
Direct drive oil-less is simply inferior to a belt drive. Noise spec? Have them plug one in at the store if you want to hear how loud it is. The pump will also never last as long running at double the speed.

Many of these small belt drive units are pretty much the same across brands. The pump on my Kobalt is identical the the Ingersol Rand model. If you look closely at the Kobalt's pump in the OP you'll see a Campbell Hausfeld logo.

Edit: Husky sells the same thing as my old Kobalt. I think even Dewalt had one.

https://www.homedepot.com/p/Husky-3...-Electric-Air-Compressor-C302H/206695048
 
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Honestly, an oil-less compressor will work just fine for the average DIY usage. I bought this 30 gallon Campbell Hausfeld oil-less compressor 15 years ago from a pawn shop. (IIRC I paid $75 for it) Build date on it is 2000, so it's 20 years old. I'v'e never had a single problem with it, still works just as good as when I bought it. Only reason I'm considering replacing it is because cordless tools have almost completely replaced my air tools so I'd like something smaller I can put under my workbench where it will be out of the way.

[Linked Image]
 
The oil free one you linked to is 70dB. That's impressive. They may be cheating (dB at how many feet distance?), but it's still a low number. I don't see how they can get the performance. Machine the whole thing out of Teflon? But it may be worth a shot.

There are well made, long lift oil freee compressors for dental and other use. But you'll pay the same or more for 1scfm or perhaps less.
 
I don't understand the difference between oil and oil free. You'd think an oiled compressor would be the best long term buy. Is one quieter than the other?

I can see oil free being better in severe cold. No oil to churn and less strain on the system.
 
Originally Posted by The Critic
Not sure why I did not notice this particular compressor until now:

https://www.cpopowertools.com/dewal...electric-air-compressor/dewndxcm251.html

25 gal, 200 psi, oil-lubricated and 6.2 scfm. From a volume standpoint, I think this may beat the 30-gal/155 psi setup in the Husky and almost equal the Kobalt. Cost with the current coupon is $519. Noise is also lower than the Kobalt. Thoughts?


I considered that model when I was shopping. Looks like a better buy than the HF version IMO.

My local Tractor Supply carries them as well as an IR version.
 
Originally Posted by dlundblad
I don't understand the difference between oil and oil free. You'd think an oiled compressor would be the best long term buy. Is one quieter than the other?

I can see oil free being better in severe cold. No oil to churn and less strain on the system.


There are pros and cons to both.

Oil free compressors are cheaper, have very little if any maintenance, and take up less space. However, they also tend to be louder and generally have shorter life. They will work just fine for the average DIYer, but they don't satisfy the tool superiority complex found here on BITOG and other forums.

Oiled compressors are quieter, generally last longer, and are better for heavier usage. They are also more expensive. If your compressor is going to see heavy use and you want it to last a long time, oiled is the way to go.
 
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