Relocating air compressor outside?

[Com_VC]

Well thinking about relocating the air compressor outside to free up some space in the garage. It's a 3hp 16cfm china type.

I was thinking of boxing it up and having a couple of grates on the side for air flow. Maybe put some sound deadening material to keep the noise down.

Also i'd probably run some steel lines from the compressor to the garage, would 1/2" do the job? Would it be ok to weld these? Obviosuly i'd soap test them afterwards to insure no leaks.

What do you's think

Thanks

[k.a.m]

why not pipe to your garage with sch 40 pvc i piped my entire shop with 1'' all my drops had air driers and drains. i did run a 2' flex line between the compressor and the pipe, never had a problem just a suggestion.

[enlpck]

This comes up every once in a while, so if you have seen this response before....

DO NOT USE PVC FOR AIR PIPING. The pressure rating is fine, but PVC is brittle and will let go without warning. Any oil residue carried over from the compressor will weaken it, vibration and impact will weaken it, age will weaken it, light exposure will weaken it (especially UV), heat will weaken it, pretty much every condition in the shop will weaken it. 'But what about water', you say? Water doesn't store significant energy at pressure. If there is failure, you have a mess. With air, if there is a failure, you have flying shrapnel. 'But I'v use it for 20 years with no problem'. Well, so have other people. It is risk assessment: Is the potential penalty worth the (relatively small) cost saving?

See: http://www.osha.gov/dts/hib/hib_data/hib19880520.html and note the conditions imposed to make the pipe permissible for use with pressurized gas in commercial installations. Also note that the original recommendation AGAINST the use of PVC came from the manufacturers.

[k.a.m]

it was a suggestion, in my shop 50'x 75' i ran pvc it has been in there for 12years without a failer at any joint it was all clamped well and also avoided any vibration issues hence the flexable line between the compressor and the rigid line all my lines were ran overhead i guess i have been lucky we run eveything from scaling guns to 1'' impacts.

[enlpck]

As to putting the compressor outside, some concerns are protection of the electrical and motor from water, keeping the noise down to avoid the neighbors pulling out all kinds of zoning rules, making sure that you can drain condensate out easily and safely (no oil residue into the ground, not spraying into your face, etc), and prevention against condensate freeze-up in the reservoir and lines.

Boxing it up well in a shed structure can take care of the protection against water and help with the noise, baffling and insulation will help more with the noise. Note that much of the noise comes from the intake.

Preventing freeze-up isn't an issue if the area never gets below freezing. If you are in an area with a winter, then you might want to consider heat tape for the bottom of the reservoir and the drain line. The thermostat on standard pipe trace for water piping turns the heat on between 35 and 40 degrees F, just warm enough to keep the water from freezing. You only need it on the bottom of the tank where the water will collect. Insulation tight to the tank isn't needed or desirable (it may hold water on the outside leading to corrosion) as long as there is protection from air movement around the bottom of the tank where the tape is. Air movement is desirable and needed around the rest of the tank for cooling the compressed air.

The size of the line needed depends on the air demand and the length of the run. Longer runs and higher demand need larger lines. If you are using a 20CFM blast setup with 50 feet of line, 3/4 is probably needed. If you are running a 5CFM die grinder with nothing but a hose between the tool and the tank, 3/8 is fine. For more info, see: http://www.chemicalprocessing.com/articles/2005/12.html (a bit long winded), http://www.parker.com/pneumatic/serv/TEC-15.pdf (charts that make the job fairly easy), http://www.airheads.net/tech/techinfo/airline.html (simple chart). Don't forget to consider the losses for things like elbows, fittings, seperators, and regulators.

[enlpck]

it was a suggestion, in my shop 50'x 75' i ran pvc it has been in there for 12years without a failer at any joint it was all clamped well and also avoided any vibration issues hence the flexable line between the compressor and the rigid line all my lines were ran overhead i guess i have been lucky we run eveything from scaling guns to 1'' impacts.

Lots of it in use, not many failures. Cost of a failure is much higher than I am willing to pay.

Add to that, in a commercial application, unless the proper guarding is in place (more cost and trouble than just using steel or copper), an OSHA inspector may close you until it is removed. It may be considered and immediate and critical hazard (I don't remember the correct wording), so no written violation and 30 days to rectify the situation. A number of building codes and local safety codes also prohibit the us of PVC for compressed gases-- this depends on your locality. Add to that, your insurance company will not be happy about it and may refuse to pay any claims related to damage or injury due to failure of the piping.

[Zrexxer]

it was a suggestion, in my shop 50'x 75' i ran pvc it has been in there for 12years without a failer at any joint <SNIP>i have been lucky we run eveything from scaling guns to 1'' impacts.The dangers of using PVC for compressed gases have been known and documented for over 30 years. The Plastic Pipe Institute recommended in January 1972 against the use of thermoplastic pipe to transport compressed air or other compressed gases in exposed plant piping. Many states have now outlawed it completely.

The American National Standards Institute/American Society of Mechanical Engineers limit the operating pressure of plastic piping distribution systems to 100 pounds per inch (psi) and prohibit the installation of such systems above ground except where ". . . the above ground portion of the plastic service line is completely enclosed in a conduit or casing of sufficient strength to provide protection from external damage and deterioration."

The fact that you've "always done it that way" and been lucky doesn't make it a good idea. It definitely doesn't make it an idea you should recommend to others.

[Hotfoot]

Probably just the type of thing I think up, but you could put inside the hood area of a rusty old Vintage car/truck front clip fixed to the side of your shop, and wire the headlights to come on when it fires up....it would be like the old Tin Lizzy was coming back to life!!...Well, I'd enjoy it!!!:p:rolleyes:

[k.a.m]

i rarely ever exceed 95 psi anyway i appreciate all the input i am sorry i mentioned it.

[Sberry]

I use it underground and put metal risers or enclose it in a sleeve. I like it for buried or under slab. Air into the storage building and back underground. I like my comps warm warm if I can help it. Some knock with cold starting, scares me a little. Low visc synthetic oil help a lot.

[Some Creep]

I've been installing air lines for years in shops. I've seen more than one auto shop shut down until they swapped out their PVC air lines for something else. Lots of other options, steel, copper, Chem-Aire (hate hanging it, spaghetti saggy stuff), etc. Yeah, there's tons of guys who've used PVC and never, ever have problems. There's just the very few that do. It fails catastrophically, i.e. it doesn't pin-hole leak like the other methods and THAT'S the reason they say 'no'. No warning, just boom, flying plastic shards. It only takes one guy clipping it with a forklift fork (seen this happen but the airline wasn't charged at the time, thank god), or a falling book off of a bench, or something small like that.


No one is insulting you for having done it, just that there are cautions against it.


1/2" copper isn't much more expensive OR much more difficult to use. Re-doing it is harder than doing it right the first time. Installation outdoors of air compressors is great but the cold on the oil in the splash-lubed China air comp pump may be bad for early AM startups. Scratches on the cylinders developed before the oil heats up enough to lube the crankcase adequately will add up over time and lead to premature pump failure. Lighter weight oil to account for this has drawbacks, too. Can you totally enclose it enough to retain heat above, say 50 degrees F? That would solve the freezing problem too.