Dear Dave,
I want to winterize my RV water lines by pumping air through them. I have a 110v electric air compressor but don’t have access to power at the RV storage facility. Yes, I could energize my portable generator, but I was looking for something more convenient like a battery-operated air compressor. I do have a 150-watt outlet in my truck’s dash panel I could use. Is there a 12v or 150-watt portable air compressor that would do the job? —Earl, 2022 Venture RV Sonic Light 169VRK
Dear Earl,
There are several 12-volt and cordless air compressors that will do the job. I just purchased a handy little Craftsman 20V portable one at my local Ace Hardware. It can be plugged into 120-volt AC power, connected to 12-volt DC power, OR it can use a 20V cordless battery. However, it did not come with a battery or charger and it’s about $85 for the set, so I won’t be going in that direction! It is very lightweight, portable, and has a maximum of 160 psi. I don’t need that much for blowing out the water lines, rather about 40-50 psi, but it can also be used to blow up a tire if needed.
Popular portable air compressor
A very popular model is the VIAIR® model 88P, which can provide up to 120 psi and only weighs about 5 lbs. There are several different models and price ranges; however, this is what the RVtravel.com staff recommends. You can find it on Amazon here.
There are several models that operate on rechargeable batteries such as DeWalt, Milwaukee, Ryobi and others. If you already have a cordless tool with a battery and charger, you can pick these up fairly inexpensively.
Whatever type you decide works best for your application, you will want to get a city water fill adapter or make your own like this one (below). I cut the end of an old garden hose off, inserted an air chuck, and tightened it with a worm clamp. This gets inserted into the city water fill and the compressor is attached to the air chuck. Otherwise, someone has to hold the air hose to the typical adapter. If you use a larger compressor, make sure you dial the pressure down to about 40 psi, otherwise you will blow the fittings apart!
Lippert has developed a product called Floë that makes blowing the air lines out as easy as flipping a switch.
The main compressor is permanently mounted in an out-of-the-way location and connected to a 12-volt source, either at the distribution center or ganged to another 12-volt source. It can also run on 120-volt power if desired. Then you install the “T” to a fresh water line and it provides pressurized air that blows out the water lines just like an air compressor. The reviews look good, but I have not tried it yet. Hopefully I’ll get a chance this summer to install and test it.
You might also enjoy this
Every RVer should have one of these portable air compressors
By Nanci Dixon
As full-timers, we gradually accumulate gear. After a rear dual tire lost its valve stem and the tire had to be replaced, we purchased a TireMinder® TPMS system. I diligently watch the tire pressure as we are driving and have come to dread the low-pressure alarm. … We just bought a VIAIR 450P-RV portable compressor and it is amazing! Continue reading.
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
Read more from Dave here.
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I store my rv for the winter until we leave for the south after Christmas, but I winterize at home before storing. You can’t do that for 1 day?
That Viair air compressor draws 288 watts, a lot more than the150 watts that Earl had available on his trucks dash & also comes with battery clips & not the plug he needed! Hopefully he’ll be able to get to his batteries while in storage!
Snoopy
I don’t know if this is a valid concern, but I’ve always worried more about air flow rate than pressure for blowing out lines. Which is why I don’t use a small “tire” compressor for this job but a tank compressor.
Maybe I’m worrying about nothing?
The issue with “blowing out water” isn’t pressure but air volume. It would be nice if compressor companies could provide airflow numbers at low pressure (10 to 30 psi) but few if any do. Here in NE Ohio I need to Winterize. My practice is 1. open all low drain point valves and faucets. 2. Bypass and drain Hot water tank.3. Remove the showerhead 4. Close low-point drains and faucets 5. connect low-pressure (30 psi) airline and one at a time open faucets for about a minute each and include low point valves and flush the toilet in this 1 at a time blow out. The One at a time concentrates the air volume to that line. After doing the blowout and with all the valves closed, I swap out the input line (suction side) to the water pump with a hose I can place in a jug of “Pink-Stuff”, I go through the motorhome and one at a time open each faucet till I get pink water out. This ensures that each line and faucet only has antifreeze in it. Flush the toilet too. I don’t depend on blowout only.
Something I will test with my next winterization: Lippert’s (nifty looking but pricey, one-trick pony) supposedly only uses roughly 15psi to blow out water lines. That is roughly the same pressure created by hobby aquarium air pumps. As Dave has recommended, I set my compressor at 40-50psi. If I can dial the output pressure back anywhere near 15psi, the compressor reserve tank will go about 3 times further for each run of the motor. That will save a lot of heat build up at the compressor.
I use found on Amazon a “Winterize Blow Out Adapter for RV, Boat, Motorhome, Camper, and Travel Trailer: Air Compressor Quick-connect Plug to Male Garden Hose Faucet Fitting” for my compressor.
I have the Dewalt cordless compressor and it does the job. Just dial in the desired air pressure and sit back.
We have the Ryobi, matching the rest of the cordless tool battery packs. The nice shape stores very easily. Lives in the Toad. Will manage the RV tires easily.