How big an air compressor

j-d wrote:
This ViAir 88P looks promisng for a 12VDC Inflator, and a good price.

Given my druthers, I'll never be without my Viair 450P.

http://learntorv.com/product-review-viair-450p-12v-air-compressor/

Takes my trailer tires up to 125psi with no issue.

This ViAir 88P looks promising for a 12VDC Inflator, and a good price.

I purchased a Slime inflator at Wally World that can run off the 12 volt battery, and can do inflation/deflation. Cost me about a C-note, but it does its job well, and will stop when the right pressure is reached.

I used to have an air compressor with a small tank, and it was louder, and wasn't really that much quicker to fill a tier up. In fact, because you had to kneel and keep the air chuck pressed against the Schrader valve, it was a lot more tiring than just screwing the connector of the Slime air compressor onto the tire valve, pushing the button, and doing other things until it hit the preset PSI and shut off.

OP here, Thanks for all the helpful advice. Made a note of the amps/watts formula. Looks like the 3 gal compressors may be a tad too much for my 1000 watt gen. Lowe's has a couple nice one and a half gal models that might work. Think I'll research Mr Wizards suggestion for a tankless model.

road-runner wrote:
The HF compressor might be good for emergency use, but for general use I'd consider it pretty lame.

I have one. Actually my third one, and "pretty lame" is a pretty good description. At it's 100-PSI rating, pulling a 16" Class C tire up from 70 to 80 takes a very long time, and I let the compressor cool after each tire. Luckily I custom Dually Valves (BORG) and tire inflation's about a twice-yearly project at most.

There's a 30-minute break-in process that needs to be done. Still, these compressors Do Not last long on long, hard runs. They use a little fabric element of some kind as the "piston ring" and when that fails the compressor is junk. So far, nobody's been able to find the repair part.

I like having it for the portability, and I'm limited by the size of my RV compartment. Otherwise I'd want a bigger one such as goes for about $100 on sale at Home Depot. RIGID I believe. I prefer "Compressor" (with a Tank) for the flexibility it offers over "Inflator" (compressor, no tank).

At $39, not a bad deal. I get probably 4 years out of a compressor. Should make portable air tanks out of my two junk ones. They look like new.

you will have better luck running a larger motor 'tankless' compressor/inflator
it won't have the heavy surge load working against a tank, kicking on an off

large tank compressor for airing tires in an RV is just extra weight
the volume and weight of the tank adds nothing to the ability to air up an RV tire

its nice for bicycles and air mattresses ,float tubes etc..to use the tank air with out power, it does not help in airing up the tire , in fact the on/off restart under load just slows down the process of airing the tire up, and makes the generator work harder, with the surge strain, instead of a nice constant load

Watts is not what you need to be looking at. Small generators are rated in volt-amps( VA), and with a motor the VA draw will be higher than the watts. The difference varies, as an approximation I'd add 10% to the watt draw of the compressor to get the VA. The linked-to HF compressor specs say 2.6 amps, so at 120 volts that would be 312 watts, increased by 10% would give 343 VA. I'm skeptical of the specs. 312 watts converts to .42 horsepower, so the motor in that compressor would have to be 79% efficient for the specs to be correct. I have a compressor with 3x the air delivery specs of the linked HF compressor and when I fill a tire it spends a lot more time pumping the tank up than delivering air. The HF compressor might be good for emergency use, but for general use I'd consider it pretty lame.

I'll add that the eu2000i will run a different 1 HP compressor I have, but just barely. And the generator sometimes overloads when the pressure switch kicks in at 80 PSI, so I have to prevent it from restarting until I draw the tank down further.

Note that you aren't directly concerned with tank size here, so much as the power requirements of the motor. It's perfectly possible for two compressors to have wildly different tank sizes and the same pump head and motor, and likewise for two to have the same tank sizes and quite different compressor heads. (It's also generally true that larger tanks and larger motors/pumps go together.)

Compressor horsepower measurements are...strange. That said, I think you're looking for something in the general range of 1 HP or so.

The little HFT compressor linked above will be on sale for $39.99 on Nov. 9th thru 12th, in the stores. I don't know about online.

Home Depot and Lowe's have some nice compressors on sale too.