Portable air compressor

Dan10K

I've seen lots of discussion about air compressors used for dewinterizing, but am wondering if anyone has had experience with a smaller, one gallon, cordless model?  Specifically I'm looking at a Ryobi 18V c/o Home Depot.  I would like something that I can easily cary in my TV so I can adapt to the seasons as I travel. Being Minnesota based we will most certainly experience freezing temperatures. ;-)

Dan10K

FYI, it appears to be 0.7 Air Delivery SCFM @ 40PSI

Sharon_is_SAM

We purchased, carry and use to winterize this Viair compressor.  You won’t win any races, but it is compact and we use it to add air to our tires.  The 70 P model may have been replaced by the 85 P model.

Horigan

I'd be concerned about relying on only 1 CFM airflow for winterizing.  To properly winterize you need good air flow, not pressure.  So you need a compressor with a tank that builds pressure that you then release when you open a faucet.  The smaller the tank the more times you'll need to build pressure and open other faucets/showers to purge the lines.  I don't think small pumps provide sufficient airflow to purge the water from the lines. 

If you're one to add antifreeze after purging, then the small pumps are probably okay.  I personally just blow the lines, don't add antifreeze, and that's worked well for many years on my T@bs and boat.

Pintoplumber

With a small compressor, the water heater becomes your air tank.

dragonsdofly

A simple trick to increase volume is to hook up your water hose (after thorough draining) to the city water port. Attach your compressor via adapter to the garden hose. Garden hoses are made to withstand 60+ psi. When you pressurize your system, keep your compressor settings below 50 psi, use the garden hose as an auxiliary tank to increase the volume of blow-out capacity. Simple, inexpensive and effective.

Horigan

dragonsdofly said:

A simple trick to increase volume is to hook up your water hose (after thorough draining) to the city water port. Attach your compressor via adapter to the garden hose. Garden hoses are made to withstand 60+ psi. When you pressurize your system, keep your compressor settings below 50 psi, use the garden hose as an auxiliary tank to increase the volume of blow-out capacity. Simple, inexpensive and effective.

Good one!

tabiphile

Once you have installed an anti-freeze winterizing kit it takes literally 2 to 3 minutes to winterize. You stick the fill hose in the jug of anti-freeze (good to 100 degrees below F), turn on your pump and open the faucets. It takes about 20 seconds for the water to purge and anti-freeze to flow. Pour anti-freeze in the drains and done. 2 to 3 minutes and you can have 100% confidence that there are no pockets of water that may remain if you use the air method.  
I would only consider using the air method is if I was on the road and needed to do a quick overnight purge.

pthomas745

@dragonsdofly @horigan This video shows the idea of how the hose acts as a tank, and he uses a bike pump to clear water.  At about the 6 minute mark is where the pump/hose test happens.  https://www.youtube.com/watch?v=Rf-DJCDPMkk&t=501s

dragonsdofly

@tabiphile, I've known about this trick more than 50 yrs. My father was a journeyman maintenance man for a major utility (DTE, Detroit Edison). He worked at several major power plants including nuclear. When the grid went down, he and his team would have to do whatever it took to restore power, and often they improvised. Using the hose as an auxiliary retaining tank was something he actually did one time, although his story included 300 ft of 4" fire hose and a six story tall turbine. Needless to say, it was just a kernel of knowledge that I kept under my hat until we had to winterize the t@b on an emergency basis while stranded at altitude in Wyoming in November. All we had was a thumb sized 12v bicycle pump and 50 ft of 1" hose. It worked. You finding the video, I can say what's old is new again.

pthomas745

Trying to picture how far I can shoot water with a 4 inch hose and a giant turbine........

tabiphile

@dragonsdofly....no question that your process can work. I'm just not sold on the blowout method. I regard it as a method that allows some risk of water freezing in the lines or faucets. Filling the lines, drains with antifreeze leaves zero possibility for a freeze up. It takes very little time and does not require anything more than a jug of antifreeze to do. Having said that, you do need to flush the stuff out of the lines to de-winterize. 

dragonsdofly

@pthomas745, with imagination, anything is possible. But, that was with 300 ft of 4" hose, which can certainly change your perspective, if not anything else.

Now that this thread has been thoroughly hijacked, back to the topic at hand.

msmith

I usually winterize for outdoor winter storage in Maine with a 3 gallon air compressor and pour RV antifreeze into the drain traps on our 2017 T@B CS-S. But we’ll be crisscrossing the frost line across the country over the next several months in the the T@B so I was excited to see that Ryobi has an inexpensive portable air compressor to blow out the plumbing system to winterize when we hit the freezing mark. Because I already have four of Ryobi’s 18v ONE+ batteries and two charging units I could just buy the tool only at Home Depot for about $20. But after looking at reviews and videos I’m leaning on buying a Viair compressor. The latest RV models shown on Viair’s website all have alligator clips for the power connection. But I’d like to have more flexibility to use the multiple cigarette ports that are in our T@B, tow vehicle, and power station. So the 85P model looks like it may fit the bill. I can always get a cigarette port to alligator clips adapter if needed. It’s three times the cost of the Ryobi but from what I’ve seen in videos it will come up to 50 pounds faster than the Ryobi and you don’t have to hold the trigger the whole time. The tip using the city water hose as a compression tank is helpful. So we could always use our manual bicycle pump with pressure gauge combined with the 50 ft. water hose as a backup compressor.

Regarding using just RV antifreeze, it’s fine for outdoor winter storage if you’re going to put the camper away and not use it at all. You just have to use an enormous amount of water to rinse the hell out of it in the spring to get all the fluid out completely. But if you want to do winter camping or you’re going to be be in warm and freezing temperatures repeatedly, blow out is the way to go in my opinion. Of course we'll still need to use antifreeze in the traps.

There are a lot of other portable air compressors on the market. The cheaper ones seem to be geared more for bicycles and balls with overheating occurring when used on tires, especially truck tires. 

https://www.viaircorp.com/portables/85p

Looking at this one as well, Viair includes it their RV line. A bit more capable, but doesn't have a cigarette port, and more money:

https://www.viaircorp.com/rvs-portables/89p-rvs

pthomas745

The only question that needs to be figured out is the power needs of the 85P.  The specs say: "Max. Amp/Watt Draw: 15A/180W."   Those numbers are just basically what the maximum amount of power the 12V ports in the trailer can provide.  I have a 70p, and I've only run it with my vehicle with the engine running.  I might have to drag that out today and see how it runs on the trailer's ports.

The other option, which is beyond my electrical skill...is to set up a 12V port that attaches to the SAE plug (the "Zamp" port).  The SAE port is wired directly to the battery, so, in essence, it would be the same setup as running alligator clips to the battery.  I've made a small cable that works with the SAE port that I've used small inverters with it.

msmith

pthomas745 said:

The only question that needs to be figured out is the power needs of the 85P.  The specs say: "Max. Amp/Watt Draw: 15A/180W."   Those numbers are just basically what the maximum amount of power the 12V ports in the trailer can provide.  I have a 70p, and I've only run it with my vehicle with the engine running.  I might have to drag that out today and see how it runs on the trailer's ports.

The other option, which is beyond my electrical skill...is to set up a 12V port that attaches to the SAE plug (the "Zamp" port).  The SAE port is wired directly to the battery, so, in essence, it would be the same setup as running alligator clips to the battery.  I've made a small cable that works with the SAE port that I've used small inverters with it.

I asked Viair if plugging the 85P or the 89P-RVS into the T@B battery was sufficient and they said maybe not, and it would be best to use the tow vehicle’s cigarette port or battery with engine running. However if connected to shore power using the T@B battery may work. I don’t know without testing. Let me know what happens with your test.

Regarding Zamp connection, that is wired for Zamp panels which have the polarities reversed. So if you use that make sure the red (positive) goes to the positive post on the battery. Something to do with the SAE plug exposing the hot wire from the panels so they reversed them. 

https://tab-rv.vanillacommunity.com/discussion/comment/113094#Comment_113094

pthomas745

Once you figure out the SAE port, it is easy to deal with.  It is wired the correct way for ....the SAE plug.  With a multimeter it takes just a moment to get straight. You just want the "hot" lead to be protected inside the plastic part of the SAE plug.  Viair gave you a standard non answer answer.  The electrical "max draw" on an electrical device is always listed as the "maximum possible power draw".  In this case, it happens to be the theoretical maximum of our 15 amp fused 12V ports, or 180 watts.  Most likely, though, the "start up" draw of the compressor might be pushing things a bit.  It rained all day here, so I never got out to play around with this!

msmith

My Tacoma cigarette port has a 15 amp fuse and that makes me a little nervous. Not that replacing a 15a fuse is difficult, but if I’m in the middle of nowhere and I need to purge the plumbing before nightfall and all I have is the pump and a gallon of RV antifreeze. If I blow a fuse I’d better be sure I have plenty more on hand. Now I see why all of Viair’s “RVS” compressors connect directly to the TV battery bypassing the cigarette port fuse, they are all 20 max amps and up.

pthomas745

I ran this earlier this morning with my ViAir 70P.  The 70P manual quotes the same "Max Power" specs: 15A/180W.  I connected the Viair to the 12V port, and attached it to the tire.  (Tire only needed a few pounds).  With the Victron in hand I flipped the switch.  The screen grab on the left is the trailer with nothing running.  The screen grab on the right is the power use with the Viair running after about 15 seconds.  While I was watching the Victron screen, right when the compressor started, the watts/amps went pretty close to the 180 watt/15 amp limit, and then immediately started to drop as the compressor got "up to pressure".  It was still dropping as the tire filled.  This compressor is rated at 1.07 CFM, so a bigger compressor might get above the 180 watt threshold. In theory, though, they should not be going above the listed 180watt maximum.   A quick look through the Amazon reviews for the 85P, with a 1.26 CFM rating, claims that most owners don't seem to have a problem with blown fuses.  YMMV.

The photo below on the right: I attached the Viair directly to my "old" battery.  (This is my trailer's birthday...I picked it up 5 years ago today, and only recently switched out the battery).  With a simple "alligator clamp to 12V adapter" the Viair worked just fine. Like this one: https://www.amazon.com/BESTEK-Cigarette-Lighter-Battery-Extension/dp/B00JOY6U7U

I also plugged it in to the SAE port with my home made SAE to 12V port adapter and it worked.  If you can't get easy access to your battery, this would also be a way to do it.  Here is an example of the cable.  As with all things SAE, you really need to make sure of the polarity of the set ups.  Adapters to make them work are not expensive. This one "seems" to be correct, but I have seen others that are not.  https://www.amazon.com/SinLoon-Cigarette-Waterproof-Extension-Charging/dp/B073WW13PF/ref=bmx_dp_qh8mzx3n_8/143-6304957-8877728?pd_rd_w=22ZtK&pf_rd_p=862b4b8b-7a18-40e3-a54d-9d43f8d57f92&pf_rd_r=HE5QTGGY5N72VFP8TQQP&pd_rd_r=34803235-d6d0-476c-80f5-f0725392d238&pd_rd_wg=Uzlz5&pd_rd_i=B073WW13PF&psc=1

msmith

The 70P has a thermal overload protector which is a nice to have but the product is discontinued. Viair’s suggested replacement units are the 84 and 85P. However neither of those have thermal overload protectors. After chatting online with Viair this morning I get the feeling the marketing department, the design department, and business development are all meeting together on a regular basis to figure out how to upsell RVers to their 300-450P line of compressors. I’ll probably go with the 85P and be careful not to overheat. Or maybe the 89P, it has a longer hose and higher working pressure rating.

msmith

pthomas745 said:

...With the Victron in hand I flipped the switch.  The screen grab on the left is the trailer with nothing running.  The screen grab on the right is the power use with the Viair running after about 15 seconds...

Is this a Victron solar controller? Where is it mounted in the T@B?

pthomas745

@msmith This is a Victron shunt display.  The Victron Connect app.

The solar controller wanders around the trailer through the years, as Nucamp found interesting places to put it. What year and model is your trailer?

msmith

2017 CSS.

My 20amp Renogy Voyager controller is mounted to the top of battery box inside the tub. Thinking of changing the setup because I don't like how the cables are flexing at the terminals when plugging in and out of the MC4 connections. Maybe mounting the controller inside a metal or plastic box with cables secured at the box wall with cable glands. This guy's using a lunch box:

msmith

Something like this would work - I'm shopping for the right size:

https://www.amazon.com/Zulkit-Dustproof-Waterproof-Electrical-Universal/dp/B081M36XXP

pthomas745

I just bought a Zulkit box last week to hold my Epever controller.  They are really nice boxes.  I used gland nuts for my "Tupperware Container Solar" box for the last year or so, and it was the only way I've been able to get strain relief on the cables at the controller.  It worked really well.