Recommendation on sizing external air compressor

windtrader · August 12, 2017, 01:30:46 PM

Using the bus air compressor to air up makes a lot of noise as I was aware of but already encountered my first complaint.

I'd like to add an external auxiliary electric air compressor to air up the bus before leaving a park. HF has a couple small ones on sale and was wondering if these will do the job or should a larger one around 6gal and 150psi be installed?

Airing up tires from the compressor would also be highly desirable.

Thanks
Don

Dave5Cs · August 12, 2017, 02:24:34 PM

The bus air is about 11CFM recovery. You just need one that is fairly quite and probably won't be as big CFM maybe 3CFM at 80PSI. Belt drives are less noisy but are bigger and take up more room. I just have a Campbell Hausfeld 2 hrp with stacked tanks in front bay. I routed a hose the the rear right side and put a NPT fitting on the pipe below the sign that says "Drain Daily" That large hose comes from the bus compressor head.

So if engine isn't running you start your Genny and or if you are hooked to the pole and run your shop air through the routed hose and a small air dryer( so you don't pump condensation into the Bus lines) into that NPT fitting. Use a double or make one male NPT fitting to connect them both when needed.

What we do is hook the hose up and start the compressor and close the bay door. It takes about 15 minutes and the system is full and we are ready to go. You can also use it to fill tires it just takes a little longer. You will need at least 125PSI to 150PSI is even better.

If you go with HF make sure you ask to run and hear it first because the cheaper ones are general louder especially the oil-less ones.
Dave

Darkspeed · August 12, 2017, 03:17:23 PM

These guys have some interesting little dc compressors as well > https://www.hornblasters.com/products/categorytype.php?t=constant-duty-air-compressors

windtrader · August 12, 2017, 04:23:16 PM

Thanks guys. The bus is outfitted for one already so its all plumbed and ready to go. It had a pancake behind the back right door. Looking on CL and can get a used 6 gal 150psi 2.6 scfm for 50 bucks https://sfbay.craigslist.org/sfc/tls/d/compressor-porter-cable/6258769909.html, better than the HF ones.

The DC units look very nice and compact without the tank but a bit pricey.

gumpy · August 12, 2017, 05:25:31 PM

Funny ad. I think I'd get rid of the wife and keep the compressor.

Anyway, that one would do the trick, but, you need to mount it in a bay, not in the engine compartment. The moisture will rust it up and seize it in short time. Did that with a small one I had on my bay door latches.

PP · August 12, 2017, 06:51:50 PM

If I was in the area I would buy it and replace the noisy HF unit that I now have. Mine is up front and plumbed into the auxiliary tank just for the suspension, foot rest, and air horns. I have another connection in the engine bay if I want to fill the entire air system, brakes, etc. Although I have a hose to do that, I rarely do. I just want to keep the bus level when parked (Prevost leveler system)
Will

chessie4905 · August 12, 2017, 07:08:23 PM

Mine is an oil less compressor of about 1 to 1 1/2 hp. I think it is a Sears. It is plumbed into air system and have a dash switch to turn it on. I don't think the previous owner ever drained the tank as it was 1/2 full of water. Probably has a 12 gallon tank. Pump up the air, start engine and go. If cold, block heater makes instant summertime. Mine is in rear baggage bay between water and waste tanks, so they absorb a lot of the noise. The previous owner spent Winters in Florida and used it primarily for keeping air suspension charged. It's great for emergency tire changes also. Good for chasing air leaks in system without the need to run engine.

kyle4501 · August 12, 2017, 07:25:53 PM

Mine has a tankless air compressor that looks like a GAST 6H

Quieter than most that I've heard. Takes about 15 to 20 minutes to air up from nothing in the tanks.

It will provide enough air to make it home if the engine driven compressor fails (or, in my case - if the air dryer purge valve fails).

Won't go past 100 psi, but if I need more, I wake up the big greasy noisy thing in the back.

mikke60 · August 12, 2017, 08:10:42 PM

On my last bus ,I built a super quit compressor. This was done by finding and older non running compressor, brand not important . I replaced the actual compressor pump with a fridge ,(or freezer ) compressor. While it had slow recovery,it would run as needed to keep bus constantly filled. Being a fridge comp., it was virtually silent. Ran about 2 or 3 minutes every half hour.

TomC · August 12, 2017, 09:25:24 PM

If you want quiet-here's what I have- the 2hp airless from California Compressor. Be sure to look at the videos http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/ Good Luck, TomC

silversport · August 12, 2017, 10:48:22 PM

I bought a 150 psi pancake compressor from harbor freight, cannibalized just the pump, installed in driver compartment, plumbed into the coach air. Works off genset and power pole, not to noisy take about 20 mins to air up, switches at driver seat & compartment were hose connection is.

windtrader · August 12, 2017, 11:09:52 PM

Going to pick up the used Porter Cable and put it where the A/C was located, the same place as the other one. If moisture becomes an issue, I'll fab some compartment or shield to separate it off. Maybe the last one bit the dust from being in that area.

Darkspeed · August 13, 2017, 06:34:27 AM

Quote from: TomC on August 12, 2017, 09:25:24 PM
If you want quiet-here's what I have- the 2hp airless from California Compressor. Be sure to look at the videos http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/ Good Luck, TomC

Tom, this one ? > https://www.amazon.com/California-Air-Tools-SP-9421-Compressor/dp/B00NGK47FK/

DoubleEagle · August 13, 2017, 06:57:42 AM

Quote from: TomC on August 12, 2017, 09:25:24 PM
If you want quiet-here's what I have- the 2hp airless from California Compressor. Be sure to look at the videos http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/ Good Luck, TomC

I have the 240V version of that double tank California. It is quieter than many other brands, but it has a short duty cycle which means that once it gets hot it will shut off until it cools down. It is made in China, so I don't expect it to last real long. I bought it direct from the company on their website as a "scratch & dent" and saved $100 compared to the prices elsewhere. It had scratches and dents alright from being shipped to someone else and returned, but it works. It is lighter because of aluminum tanks, and one person can pick it up (weighs about 1/2 of a 8D battery), but, while being quieter than others, it still makes noise that would be heard in a campground in the early morning when you are trying to start up discreetly. If you put it in a insulated box, it will definitely need supplemental cooling.

gumpy · August 13, 2017, 07:09:30 AM

Quote from: windtrader on August 12, 2017, 11:09:52 PM
Going to pick up the used Porter Cable and put it where the A/C was located, the same place as the other one. If moisture becomes an issue, I'll fab some compartment or shield to separate it off. Maybe the last one bit the dust from being in that area.

Maybe. And this one will too!