120 volt tankless air compressor is much faster than 12v for airing up

[BeaverMan]

I recently added a 2200 watt inverter to my offroad setup and decided to try a tankless 120v air compressor. Under 2 minutes per tire- over three times faster than a very expensive 12v unit. Put this to good use after recent flash floods. Try one you might like it. I found this one on the Home Depot website- California Air Tool- CAT-10TL

 

[Metcalf]

I recently added a 2200 watt inverter to my offroad setup and decided to try a tankless 120v air compressor. Under 2 minutes per tire- over three times faster than a very expensive 12v unit. Put this to good use after recent flash floods. Try one you might like it. I found this one on the Home Depot website- California Air Tool- CAT-10TL

Just curious, what 12V electric where you comparing against?

 

[Herbie]

This isn't surprising - the amount of air moved is going to be proportional to the amount of available power, with heat being the only other limiting factor for the 120v unit.

EDIT for clarity: Just look at the size of the cables between a 12v compressor (10, 12 gauge?, probably 360 watts?) versus what's required for your 2200 inverter.

 

[Alloy]

Two Viair 400C
- provide redundancy
- are higher cfm
- draw less power
- don't need an inverter
- go up to 150psi

 

[thebmrust]

Did a quick search… prices are near equal for (2) Viair 400C vs the CAT10L + 2000w inverter.

The difference, the inverter can be used for other electronic devices too. But the compressors can be used for tools.

 

[Superduty]

I recently added a 2200 watt inverter to my offroad setup and decided to try a tankless 120v air compressor. Under 2 minutes per tire- over three times faster than a very expensive 12v unit. Put this to good use after recent flash floods. Try one you might like it. I found this one on the Home Depot website- California Air Tool- CAT-10TL

What was the "very expensive" 12v unit?

 

[1stDeuce]

Great post, and a good idea too!
It's very simple folks... P = I x V, or spelled out, Power equals Current times Voltage. With 10x more voltage, you need 10x less current to get the same power.

The 120v pump the OP listed pulls 7.5A at 120V which is (7.5Ax120V) 900 Watts of "power" for airing up tires. That means that your 12V 2000W inverter is supplying 900W to it by pulling 900W from your truck at ~13V, assuming it's running and has a decent alternator, which works out to (900W/13V) 70 Amps of draw. If the expensive 12V pump ran off a cigarette lighter, about the most power it will have for airing up is 200 watts. (15Ax13v)

If you're willing to go to battery clamps or Anderson connectors, Dual Viair 400C's will pull about 60 Amps, which is only a bit less "performance" than the 120v setup, but dedicated only to airing up tires and such, rather than being able to also power your house in times of need.

I just ordered a 2000w pure sine inverter that I'll be installing in my truck too. I am also replicating the factory dual alternator setup to go along with it so I can get more amperage at idle or not far above. My intention is that it can do generator duty to power the house or whatever other 120v things I might need when camping or working around the "ranch". Going with the dual alts and inverter will cost me about the same as buying a little 2200w inverter generator, but seemed more useful. I really like the redundancy of dual alts, since I had the factory alternator quit charging on me just before 200k, and the reman replacement now has over 100k miles on it...)
(Rainman Ray's Hurricane video has him using just under half a gallon of fuel per hour running his house off his idling Duramax, and we have pretty much the same year truck.)

I will keep using my single Viair 400C to air up tires, since it's already mounted to the truck, and since I don't have a small 120v compressor, nor do I want or need one at present...

 

[Metcalf]

I'm still curious what the 'very expensive 12v unit' was?

The 120V compressor listed is 3.1cfm @ 40psi and 2.2cfm at 90psi

ARB Twin 12V ( an expensive 12V unit ) is listed as 4.68cfm at 29psi ( and 6.16 at 0psi )
3/4hp Puma 12V ( mid range ) is 3.3cfm @40psi and 1.36 @ 90psi
Viair 400c 12V (mid range ) is 2.62cfm @ 0psi, 2.01cfm @ 40psi, 1.52cfm @ 90psi
Oasis XD3000/4000 12V ( monster and expensive ) is 15cfm at 0psi, 10cfm @ 50psi, 9cfm @ 100psi
Sherpa Big Air 12V ( more expensive than an ARB Twin ) 10+cfm @ 0psi, 8cfm at 40psi, 5.2cfm @ 80psi

Just a note, in my testing, you can only shove about 5cfm through a normal tire valve.

Removing the valve stem core makes a pretty big difference in air up speed if you want to go that far, but hooking up more than one tire at a time if you have a BIG compressor setup would probably be 'faster' overall.

 

[stevo_pct]

How well do you think this tankless compressor would work for blowing compressed air (for cleaning stuff off, blowing dirt out of stuff, etc.).

 

[BeaverMan]

The DC compressor was a Smittybilt 2781 5.65 cfm and draws right around 45 amps. Maybe the 2781 is a midgrade unit but not cheap. Prices have come down alot since I bought it. I have a Ram 2500 with offroad camper so inflation pressure is much higher than most- 60psi front 65psi rear. The CAT 10-L is a 1hp unit only rated for 3.1 cfm at 40 psi but is 3 times faster.
The 10-L draws about 7.5amps so total watt draw is more than 2781. I installed the inverter because I wanted to run a Instant Pot and hot plate. I decided to take a chance on the 10-L because I already had a Kobalt dual tanked compressor that used similar 1hp compressor motor and it was very quiet and worked well for a small jobsite compressor. Numbers do not lie and I am very happy with my setup. I have a two lithium batteries for the camper and run the inverter off them.

 

[Herbie]

The DC compressor was a Smittybilt 2781 5.65 cfm and draws right around 45 amps

Woah, lots of stuff to address there:
1) That quoted CFM is almost certainly at 0psi - which is the normal way to quote max volume. Metcalf's example table above shows how more high-end compressors give their CFM ratings, and how much they fall off once pressure comes into play. In fact, I find it very telling that Smittybilt doesn't quote the high-psi flow rates, because they're almost certainly bad.

The CAT 10TL does the same thing, quoting 3.10 @ 40psi and 2.20 cfm @ 90psi. At your usage of 60-65psi it's safe to assume it can push somewhere between those values. And, yeah, stevo_pct's math is correct (7.5A x 120v) = 900w, give or take.

2) The Smittybilt's datasheet says 45A MAX. That's likely the inrush current. Note that it ships with a 30A fuse. It's quoted as a 1/3hp motor, so real current consumption is probably closer to ~20A (12x20 = 240w, which is very close to 1/3 of 746w)

For all of that, not sure you're getting an apples to apples comparison with a 1hp AC compressor (that requires a fairly stout inverter to run) versus a 1/3hp DC compressor. Even the beefiest ARB twin-compressor units only add up to be in the 1/2hp ballpark.

 

[4000lbsOfGoat]

A PowerTank will fill tires faster than any compressor with the added benefits of being silent, having no moving parts, and not requiring electrical hookups. Just sayin'...

 

[Metcalf]

The DC compressor was a Smittybilt 2781 5.65 cfm and draws right around 45 amps. Maybe the 2781 is a midgrade unit but not cheap. Prices have come down alot since I bought it. I have a Ram 2500 with offroad camper so inflation pressure is much higher than most- 60psi front 65psi rear. The CAT 10-L is a 1hp unit only rated for 3.1 cfm at 40 psi but is 3 times faster.
The 10-L draws about 7.5amps so total watt draw is more than 2781. I installed the inverter because I wanted to run a Instant Pot and hot plate. I decided to take a chance on the 10-L because I already had a Kobalt dual tanked compressor that used similar 1hp compressor motor and it was very quiet and worked well for a small jobsite compressor. Numbers do not lie and I am very happy with my setup. I have a two lithium batteries for the camper and run the inverter off them.

Ok, that helps explain a lot. That Smittybilt is about 1/3hp vs the 1hp you are using now....no wonder you are seeing 3x the performance.

You are right about the performance of the Puma 12V compressor for people following along. That would be 3.3cfm at 40psi.
I run one on my #LX45 project, and it is adequate, but not amazing. ( 40" tire )
The ARB twin in my flat fender is pretty dang good ( 35" tire ) ( and pushing that 5cfm at 29psi which is about the max I think you can shove through the valve)

I have been looking for something 'more' lately. I think to keep me happy long term, it is going to have to be 10cfm at 40psi or so. That is going to be 2hp probably.

 

[Metcalf]

A PowerTank will fill tires faster than any compressor with the added benefits of being silent, having no moving parts, and not requiring electrical hookups. Just sayin'...

You can only shove about 5cfm through a normal tire valve, just sayin....

I did the CO2 tank for a time. For me, it was bulky, heavy, had issues freezing up, and always got low or ran out at the wrong time. ?