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08-09-2019, 08:36 AM
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#1
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Family Vacation Member
Join Date: May 2019
Location: Kansas
Posts: 204
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Air Compressor Suggestions
Recently, while camping above 7000' for about a month the nitrogen filled tires on my travel trailer dropped (in all 4 tires) from 65 psi to 55 psi. The tow vehicle (regular air) dropped from 60 psi to about 52 psi. No place I went had nitrogen, and very few gas stations have air compressors these days. So, I'm giving up on the nitrogen since I can't find it when I need it. I have a portable power pack for jump starting the vehicle that has a built in air compressor. However, it took nearly an hour to raise one tire from 52 psi to 60 psi, then it crashed and won't pump air any longer.
So the question is: what 12 volt air compressor will get you up to 65 psi in a reasonable amount of time without self destructing? Any suggestions?
__________________
Dustin and Doris
2018 Crossroads, Sunset Trail 33CK,
38', 7600 lbs empty, 8300 lbs loaded.
2016 Tundra: 5.7L with towing package with added "Roadmaster Active Suspension"
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08-09-2019, 09:20 AM
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#2
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Full Time Camper
Join Date: Oct 2009
Location: Texas
Posts: 745
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This link may be helpful.
https://bestofmachinery.com/best-12v-air-compressor/
The Kobalt looks interesting as it operates on both 12v and 120v.
__________________
Russ
Forney,TX
2010 Cruiser CTX CT29RLX
2009 F-150XLT
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08-09-2019, 09:47 AM
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#3
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Site Team
Join Date: Dec 2007
Location: WI.
Posts: 9,151
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08-09-2019, 10:00 AM
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#4
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Family Vacation Member
Join Date: May 2019
Location: Kansas
Posts: 204
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thanks Lloyd,
Odd, I did a search for "air compressor" before I posted and this link does not show up. Sorry for a repeat question.
Dustin
__________________
Dustin and Doris
2018 Crossroads, Sunset Trail 33CK,
38', 7600 lbs empty, 8300 lbs loaded.
2016 Tundra: 5.7L with towing package with added "Roadmaster Active Suspension"
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08-09-2019, 12:52 PM
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#5
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Site Team
Join Date: Dec 2007
Location: WI.
Posts: 9,151
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Hey Dustin, no problem. Just because you couldn't find the link, don't be afraid to ask a question.
Some of us have been here a little longer and maybe remember a certain thread-- which also makes it easier to do a search for it. You can also use the (advanced search) function.
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08-09-2019, 09:21 PM
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#6
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Full Time Camper
Join Date: May 2012
Location: N.C. Mountains
Posts: 2,406
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Nitrogen is a rip off. You’ll be fine with just air. Even my tire dealer agrees it’s a ripoff.
__________________
*2016 CAF25SE Cruiser Aire 5er. *2020 Chevrolet 2500 HD Custom
*Ted & Tricia (Mimi - Teacup Poodle/ Sailor - Maltipoo)
*I have tried to live my life so that my family would love me and my friends would respect me. The others can do whatever the Hell they please!” —John Wayne
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08-15-2019, 02:36 PM
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#7
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Weekend Camper
Join Date: Aug 2010
Location: Minnesota
Posts: 30
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Nothing better than a Viair if you want a 12 volt powered compressor. Not inexpensive but very reliable.
__________________
Don and Kathy from MN.
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08-16-2019, 12:38 PM
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#8
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Family Vacation Member
Join Date: May 2019
Location: Kansas
Posts: 204
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120 volt compressor reliability
Thanks to everyone that replied to my request for 12 volt compressor ideas. In the end, I opted for a 120 volt compressor. Here’s why:
Air Compressor Purchase:
After studying the 12 volt air compressor specifications and product reviews of many 12 volt compressors I decided since I have a 120 volt generator I’d purchase a much more reliable 120v compressor. Argument for the 120 volt compressor:
Since the most likely scenario for airing a tire is to only raise the pressure in a low tire from say 50 psi to 60 psi then what is needed is a compressor that can move a “high” volume of air into a relatively high starting pressure of 50 psi (a low tire). In the past several years I’ve burned up two 12 volt compressors airing tires on my riding lawn mower. Though frustrating, I could just move the mower closer to the garage and fill the tires with my 20 gallon Sears compressor. If I’m camping in a remote location, I don’t have the luxury of finding a 20 gallon Sears compressor sitting idle waiting for me. I was hoping to find a reliable 12 volt compressor but after reading the reviews of many of them I’ve concluded: 1) they struggled to top off a large tire in a short period of time, often taking as much as 30 minutes, and 2) the compressor cylinder is so small and the duty cycle (usually 5 minutes run, 5 minutes off) is so short that to avoid cooking the compressor it should really take as much as an hour to top off even one tire. Neither the performance nor the reliability is there.
What is needed is a compressor with a large enough cylinder to move high volume at high pressure in a short time. In the end I opted for this 3 gallon, 150 psi, 29 pound, 120v compressor that will move 2.8 cubic feet of air at 90 psi. It has a 50% duty cycle. Cost was $109 at Menards after the 11% rebate.
Fini Advanced™ 3-Gallon 150 PSI Portable Electric Hotdog Air Compressor
Model Number: F3OL197N Menards® SKU: 2079001
Menard’s has several versions of this compressor with various options and even different piston sizes. This write up is for the Fini model F3OL197N.
Here’s the performance of the F3OL197N:
To raise the pressure on a LT275/65R18 tire from 50psi to 60psi will require 2.17 cuft of air, or 17.36 gallons of air. This 3 gallon tank can be filled to 150 psi, unplugged from the outlet, carried to the low tire and when the tank pressure drops to 90 psi the tire has been inflated from 50 psi to 60 psi. That process only takes about 2 minutes. (assuming the truck tire is an LT275/65R18). Carry the compressor back to the 120v source, pump it up to 150 psi (30 seconds) and go do another tire. In this scenario, the compressor is well within the 50% duty cycle rating and you’re topping off tires at the rate of 2 minutes per tire.
In actual practice, what is described above (and below) is exactly what happened. The math predicts that outcome and I was amazed that that is what actually occurred.
For those who are interested in the math it’s included below. For those who don’t care about the math you can skip the rest of this write up.
‘--------------------------------------------------
Here’s the math:
My tow vehicle tires, LT275/65R18, actual measurements were:
Radius is diameter divided by 2.
R2 = 31” / 2 R1 = (17” – 1”) / 2 (wheel actually measured 17”)
H2 = 10” H1 = 10”
R1 is 17 – 1 because the inside of the metal wheel is not flat, it’s convex, so it holds more air.
Determine the volume of the tire: LT275/65R18
V2 = [ pi * (R2*R2) * H2 ] – [ pi * (R1*R1) * H1 ]
Where V2 is the volume of the tire
Pi = 3.14
R2 = radius of the outside diameter of the tire ( R2 squared )
H2 = width of the sidewalls of the tire (what holds air, not just the width in contact with the ground)
R1 = radius of the metal wheel – 1” ( R1 squared )
H1 = width of the metal wheel
Therefore:
V2 = [ pi * (R2*R2) * H2 ] – [ pi * (R1*R1) * H1 ]
V2 = [3.14 * (15.5 squared) * 10] – [ 3.14 * (8 squared) * 10]
So the volume of my LT truck tire is:
V2 = 7543 – 2009 = 5533 cu in = 3.20 cu ft = 25.62 gallons
(1728 cu in per cubic foot and 8 gallons per cubic foot)
‘-----------------------------------------
How much air will it take to inflate the tire to 60 psi?
V2 = (P1 * V1 ) / P2
Where:
V2 = volume of air required to fill the tire to the desired air pressure
P1 = desired air pressure
V1 = volume of the tire
P2 = static air pressure (assume 14.7 psi)
Therefore:
V2 = (25.62 gallons * 60 psi ) / 14.7
V2 = 104.57 gallons or 13.02 cu ft.
In order to inflate the tire to from zero to 60 psi I’ll need to pump in 13.02 cu ft of air or 104 gallons.
If I do the same math but assume a desired air pressure of 50 psi then the tire will hold 10.85 cu ft of air.
‘-----------------------------------------
Therefore: to top off a tire from 50 psi to 60 psi I’ll require 2.17 cu ft of air or 17.36 gallons of air.
From above:
To inflate from 50 psi to 60 psi I’ll need:
13.02 cu ft - 10.85 cu ft = 2.17 cu ft or 17.36 gallons
‘-----------------------------------------
Let’s see what the 3 gallon Fini model F3OL197N can do for us; recall it will inflate to 150 psi and holds a volume of 3 gallons.
V2 = (P1 * V1 ) / P2
V2 = (150 * 3 ) / 14.7 = 30.61 gallons of air at 150 psi
Assume I fill the 3 gallon compressor tank to 150 psi, carry it to the low tire and inflate the tire from 50 psi to 60 psi, what will the pressure dial on the tank read: 150 – 60 = 90 psi.
And, I will have removed 11.63 gallons of air from the tank or 1.54 cu ft. The compressor will pump 2.8 cu ft of air per minute at 90 psi. So the tank can be refilled in about 31 seconds and ready for the next tire.
V2 = (P1 * V1 ) / P2
V2 = [(150 – 60) * 3] / 14.7
V2 = 90 * 3 / 14.7 = 18.37 gallons remaining in the tank
From above:
30.16 gallons (filled) – 18.37 gallons (remaining) = 11.63 gallons was removed
The tank held 30.61 gallons (at 150 psi), it still holds 18.37 (at 90 psi) gallons so we removed 11.63 gallons of air (at a falling pressure).
So the bottom line is:
The 3 gallon Fini model F3OL197N seems like the ideal, light weight compressor for topping off low tires while staying within the duty cycle of the compressor (allowing it to cool off between fills). Allowing you to top off 8 tires in about 15 minutes. Assuming you have access to 120 volts when you need it. If you were to run the compressor full time while filling tire after tire you would violate the 50% duty cycle and risk cooking the piston/cylinder. I bought it, took it home and tried it and by golly that's just what happened. Fini is an Italian company, been making compressors for 50 years and offers a 2 year warranty of the compressor.
Happy camping!
__________________
Dustin and Doris
2018 Crossroads, Sunset Trail 33CK,
38', 7600 lbs empty, 8300 lbs loaded.
2016 Tundra: 5.7L with towing package with added "Roadmaster Active Suspension"
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08-17-2019, 06:44 PM
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#9
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Seasonal Camper
Join Date: Sep 2012
Location: Rockport, TX
Posts: 419
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Wow, never realized airing a tire up was that complicated!
__________________
Will
2013 Chevy 3500HD
2012 Rushmore 38CK
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08-17-2019, 07:21 PM
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#10
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Site Team
Join Date: Jun 2015
Location: mo
Posts: 2,093
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I carry a Campbell Hausfeld pancake compressor. I have a good size inverter so i have 110 to run it. Knock on wood i have never needed it but others have.
__________________
2009 Seville VF32KS
2019 GMC Sierra 3500HD Crew Cab Denali.
6.6 Diesel standard box.
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