Questions about Rapidair air lines

Rapid air makes 2 different lines of 1/2 products:

The 1/2 OD uses quick push-to-connects. This may be plain plastic tubing.

The 1/2 ID Maxline seems to have aluminum in the tubing, and more robust connectors, at twice the price (actually some fittings are 3x or 4x)

1) Which one did you use and are you happy with it?

2) Anyone do in-wall plumbing using either of these products?

I'm thinking the more expensive version might be better for in-wall plumbing, i.e. less chance for future leaks.

3) Any tips for in-wall installations?

Thanks,

Distance ran and volume/loss might determine the id you choose. What are the air needs do you have? What distance are you running? What is the supply compressor? Ease of adding drops later is a big point of running rapidair. In wall kinda defeats that benefit.

I'm looking at the same decision myself. I only have a 2 car garage, and a smaller compressor, so I was leaning towards the smaller setup but then realized the larger pipe and nicer fittings was only a little more expensive and at least the kit I saw had mounting brackets and an additional drop.

I used about 150 ft of the plastic pipe, 8 outlets: 4 in main shop, one in welding room, one at machining, one on a big reel near garage door, and one outside on the other end of the shop. I use the outside one a lot more than I imagined. I ran the pipe overhead in the trusses then down the walls between the studs. This was a lot simpler then running it through the studs. I use a one-hand quick connect on each outlet. I used their aluminum block outlet manifolds and came through the wall into the back.

I tested each outlet on the bench for leaks with compressed air before installing and tested each run as I went. To test I connected a valve and one of their fittings to an air line and inserted a foot or so of the tubing. Each time I tested something I cut off a little of the tubing to for a clean connection. No leaks on the outlet manifolds with good teflon tape.

I made three major runs each with a cutoff valve so I could isolate a section if needed. All my walls are panels put up with screws so I can remove them for any electrical or air repairs or modifications. In 3-4 years I've had no leaks.

BTW, this oblique photo (tight spot) shows my air controls on the outside of my sound-insulated compressor closet - in the shop so I can monitor and control everything easily. Main electrical cutoff, pressure gauge, main valve, moisture trap, water separator, desiccant dryer, regulator, and valves to the three runs.
Attachment 357237

I've read that that industrial installations sometimes make the main delivery line a large loop to increase flow at any drop. Also, they suggest putting the trap and driers at least 25' from the compressor to allow the hot air to cool so water vapor in the air will condense and can be collected before it is sent into the distribution lines. Sorry if this is a repeat - can't remember where I mentioned this recently.

JKJ

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Originally Posted by John K Jordan

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BTW, this oblique photo (tight spot) shows my air controls on the outside of my sound-insulated compressor closet - in the shop so I can monitor and control everything easily. Main electrical cutoff, pressure gauge, main valve, moisture trap, water separator, desiccant dryer, regulator, and valves to the three runs.
Attachment 357237

I've read that that industrial installations sometimes make the main delivery line a large loop to increase flow at any drop. Also, they suggest putting the trap and driers at least 25' from the compressor to allow the hot air to cool so water vapor in the air will condense and can be collected before it is sent into the distribution lines. Sorry if this is a repeat - can't remember where I mentioned this recently.

JKJ

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John, Did you use the 1/2 OD hose (plastic connectors) or 1/2 ID hose (metal connectors).

Using a manifold and home runs is an interesting (brilliant) approach in terms of in-wall leaks. That would make the only connection right at the back of the wall outlet: basically there is only pipe in the walls, no connectors.

RapidAir also recommends using a loop.

Quote:

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Originally Posted by Mike Heidrick

Distance ran and volume/loss might determine the id you choose. What are the air needs do you have? What distance are you running? What is the supply compressor? Ease of adding drops later is a big point of running rapidair. In wall kinda defeats that benefit.

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Thanks Mike for the question.

Air use will be mostly for dusting, small nail guns, and filling tires. I already have a 4-stage HVLP for painting. Current compressor is a PC pancake, that may eventually get swapped out for something with a 20 gallon-ish tank, but it works fine now other than the noise which will go away when it is in the new machine room.

Quote:

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Originally Posted by John K Jordan

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Attachment 357237

... Also, they suggest putting the trap and driers at least 25' from the compressor to allow the hot air to cool so water vapor in the air will condense and can be collected before it is sent into the distribution lines. Sorry if this is a repeat - can't remember where I mentioned this recently.

JKJ

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A thought: I could do a 25' run of pipe for cooling inside the machine room. E.g., take off from the compressor vertically to the ceiling, then a zig-zag going down the wall for the 25' cooling length, then connect into regulator, water trap, dryer, manifold,...

Perhaps the downside to this is the machine room won't be air conditioned,... Hopefully the lack of AC won't be a problem for the compressor and DC in our hot Texas climate.


Machine room is roughly 7'*7'*10'. It's planned as a sealed room (except for makeup air) and I have a mini-split in the shop so there is no chance to put a register in the machine room anyway.

I ran the smaller stuff and was never hurting for air. My use is as you describe. I found I used air so seldom that when I re-org'd the system has never gotten hooked back up. I'm in a 22 x 32 space along with a washer/dryer and water heater though so it is hard to get very far away from anything.

A couple of thoughts;

First, if it were me I would finalize my compressor choice before I would worry about plumbing. If I were using a pancake compressor for shop air I would just use a hose to get the air where I needed it, I wouldn't bother going crazy building a system for air delivery and hooking it to a disposable air source.

Second; for your intended use you don't need to go to any extremes for air drying. just use a small cartridge type dryer either at your regulator or at the point of use to catch the big stuff. Length of run and turns/restrictions will limit your available volume, no sense in adding 25' of pipe and a bunch of bends to the run and unless you are using metal pipe you will not get much cooling anyways.

Decent 60 gallon hobbyist grade compressors are available for short money these days. My recommendation would be to start with a compressor that will provide +/- 10 CFM and build your system out from there. The large receiver will take care of most of your moisture issues without having to go to great lengths.

Thanks Glenn and John.

I had a plan for the machine room, and a new IR vertical compressor, but that went south when I met with the electrician and he wants to put two 200 AMP cutoff switches inside that room, which requires moving the DC into the space I had previously reserved for the compressor. I won't know exactly how much compressor space I have until the new electrical meter and cutoffs switches are in, which is going to be pretty late in the build process. Unfortunately, I need to be plumbing the airlines simultaneous to this.

I have a LOT of crap to run in the wall for the recording studio and I have to stay ahead of the contractor crews, which have been 6-15 guys onsite each day.

This build is going fast, looks like I'll be ready to move in in late June so I am ordering a CU300 and MM16 today. FWIW, there is currently a sale going on for CU300's, for anyone on the fence. I like John's home-run and manifold approach, so I think I am going to order two of the Maxline 1/2" starter kits: 200' of tubing, 6 air 'stations'.

The short story: I can't pick the compressor before ordering the air lines, but at least I do know my supply requirements and 1/2" ID should be fine.

Mark, the cutoff switches don't necessarily need to be "in the closet"...perhaps that's a solution. ;) They can be in a stud bay and flush to the wall.

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Originally Posted by Jim Becker

Mark, the cutoff switches don't necessarily need to be "in the closet"...perhaps that's a solution. ;) They can be in a stud bay and flush to the wall.

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The meter needs to go on the outside wall. The electrician wants to have the two cutoffs right behind the meter on some kind of wire runway. There is also a junction box in the machine room but on an interior, opposite wall.

I don't want the cutoffs in the shop area, the very little space I have between windows is already reserved for vertical DC runs and 110/220 outlets.

I'll ask him about flush-mount cutoffs, I didn't know they existed, but then again they would take up insulation space.

I'm not overly concerned about the compressor, my use is very limited, but I would like more than 20 seconds of air dusting before the compressor kicks in, so I need a bigger tank.

Quote:

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Originally Posted by mark mcfarlane

John, Did you use the 1/2 OD hose (plastic connectors) or 1/2 ID hose (metal connectors).

Using a manifold and home runs is an interesting (brilliant) approach in terms of in-wall leaks. That would make the only connection right at the back of the wall outlet: basically there is only pipe in the walls, no connectors.

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I don't remember the ID or OD but the connectors were plastic, slip on spring loaded, removable. I do use tee connectors in the ceiling only, one at each drop except at the end. My run to my maintenance/machining room has two outlets (one tee). The rest of the shop has two on one line (one tee) and three on another line (two tees). So far, no leaks.

Note that I did have problem with the my second 100 ft coil of plastic pipe. Perhaps it was a problem with the manufacture but it was harder and less flexible than the first coil and I had trouble getting the connectors to seals. A call to Rapid Air and they sent me a new coil immediately.

As for the moisture and the initial 25', I think copper from the compressor to the first trap would be best heat exchange, even if the room is not air conditioned. If the initial part goes straight up then the rest gradually slopes down, any moisture that condenses can run down to the trap. I made a trap from a brass tee, a brass nipple, and a valve at the bottom to drain. BTW, I used two brass unions to allow me to connect and disconnect my plumbing from the stuff that goes through the wall. (I've never made anything like this so it was all on the fly - there are probably better ways.)

I discovered in my last shop that my cheap water separator pulled a lot of water from the air. With a temporary short run from the compressor to the water separator in this shop, the separator caught NO water. It all goes right through in the air.

Yes, you can simply add a desiccant dryer to the line and forget about condensing and catching the moisture. However, there is one big problem.

The desiccant dryer (I use this one: https://www.amazon.com/gp/product/B002PR8ZXK) does indeed catch all the uncondensed moisture in the air. The problem is the cartridge gets loaded with water fairly quickly. I weigh the cartridges before and after use and it was surprising how much water they collected. The cartridges are expensive and I'd go broke replacing them as directed. I found that I could cheat and take the cartridge apart and just replace the decissant. I bought some indicator desiccant which changes color from dark blue to light pink when it needs changed. (I bought this: https://www.amazon.com/gp/product/B000OUXA2Q) I put the desiccant beads in the oven and dry them until they are bright blue again. They can be "recharged" and reused repeatedly.

BTW, I need very dry air for my plasma cutter in my welding room. I use a second in-line disposable desiccant dryer there. The DeVilbiss upstream works so well I've never had to change the in-line dryer.

BTW, I'm sure you know this but for someone else reading it is not recommended to use PVC pipe. I've read reports of it getting brittle and exploding, throwing sharp shards of pipe across the room. Recommended are copper, iron, or something like the RapidAir. However, iron can rust inside and foul things up.

JKJ

Quote:

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Originally Posted by John K Jordan

I don't remember the ID or OD but the connectors were plastic, slip on spring loaded, removable. ...
JKJ

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Thanks John, It appears you used the less expensive 1/2" OD stuff, about 1/2 the price of the 1/2 ID pipe kit. Sound like that might be good enough.

You'll be surprised about how much you may use compressed air and the compressor, small or large, will likely be as noisy or more noisy than your cyclone. So hopefully you can get it accommodated in the closet. I know I'm truly thankful for that in my shop!

I second Jim's comment about putting your compressor in a closet. Really helps with the noise in the shop and the house (Basement shop in my case).

I used the Rapid Air 1/2" plastic line kit for my 1000 sq foot shop. I ran a main loop around the perimeter of my shop with multiple drops. I even ran a connection into my garage. Easy to install with very few leaks (leaks were my fault in not seating the lines into the push connections completely). Seems to give plenty of air.

There is a machine room for the compressor and DC. I should have no problem getting at least a 20 gallon in there.

Thanks everyone for the help. I just ordered two of the 1/2" OD starter kits and 4 tee fittings to give me 4 drops from the recommended 'air loop' configuration.

I really wanted to try DIY copper but 3 of the 4 drops are on exterior walls and there is only about 4 inches between the double top plate and the sheathing. There is basically no room to solder the joints without a novice like me lighting up the top plate or the roof sheathing, which would really spoil my new build.

I put the smaller kind in my walls back in 2011. No leaks and everything still works well. I have a 2-stage compressor and keep it regulated at 90 PSI.

I have 3/4" FastPipe out of my compressor because I had visible runs that I wanted straight. Once I get a few rooms over, I switch to 3/4" MaxLine (Pex-Al-Pex). The FastPipe is a dream to install. The 3/4 MaxLine is a bit of a bear to straighten. I just received RapidAir's straightener today. Time will tell if it was worth the price.

A few photos of my setup thus far..
Attachment 358301Attachment 358302Attachment 358303Attachment 358304Attachment 358305Attachment 358306

Thanks everyone. The new lines are installed and are holding pressure at 100 PSI. Life is good.