Buying a compressor to save money

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Gandalf-ish

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I tried browsing a few threads before posting, seeing a lot of questions based around "are you doing this to save money?" But there's no real substance as to why this is a common question. I dive 3-4 times per week, and getting a fill at $10+tax is costing close to $250/mo. I'm considering a compressor to save money on fills. What's the logic behind the concern about trying to save money?
Do none of your local dive shops do air fill cards? Here in Victoria, both main local shops do 10 fill punch cards, and unlimited yearly air fill cards; for two tanks in both cases. I pay $250 CDN for unlimited fills on my 2 Faber HP 100s. That also includes the occasional top off on my 30cu pony for free. Last year, I did 193 dives.
 

rob.mwpropane

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I'm the IT guy for a fire department. I wonder if the standard they maintain is acceptable for SCUBA tanks.
This is exactly where I got a lot of my air prior to owning my own. If I wasn't looking for something mobile, I would have jumped on a compressor from a FD in a heartbeat. They're fairly well taken care of, kept inside, routine maintenance. You can find them up for auction/ sale quite a bit.
Would be a bit overkill for just one diver I think, but worth looking into.

As of now, I have 3 firehouses I can go to to fill tanks, sadly they can only fill singles as they want the tank in the blast chamber.
 

rob.mwpropane

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Do none of your local dive shops do air fill cards? Here in Victoria, both main local shops do 10 fill punch cards, and unlimited yearly air fill cards; for two tanks in both cases. I pay $250 CDN for unlimited fills on my 2 Faber HP 100s. That also includes the occasional top off on my 30cu pony for free. Last year, I did 193 dives.
This would be the way to go. Absolutely no one within 2 hrs driving offers this. I asked.

In FL I found fills for $3... for that price i would never have gotten a compressor. It's just not like that here in Northern MD.
 

Rol diy

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An oxygen concentrator, that are used in hospitals, and in homes, is a membrane system, makes about 95% O2.
The one I have, specs out a 5 liters per minute, cost me 800$ with a bottle refiller,
I don't have a conventional compressor,,, and haven't done the math, but with a small compressor and a VDF it should come close to making enough O2 for a stick,
 

grf88

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An oxygen concentrator, that are used in hospitals, and in homes, is a membrane system, makes about 95% O2.
The one I have, specs out a 5 liters per minute, cost me 800$ with a bottle refiller,
I don't have a conventional compressor,,, and haven't done the math, but with a small compressor and a VDF it should come close to making enough O2 for a stick,
This type of concentrator does not use a membrane system but rather sieve beds that alternately absorb and release nitrogen in a cycle with the nitrogen reduced air going one way and the released nitrogen going another. It does cause a build up of argon but in open circuit this is not a problem at typical depths.

There are a number of instruction videos on You Tube on how to build one.
 

tbone1004

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I'm a Fish!
An oxygen concentrator, that are used in hospitals, and in homes, is a membrane system, makes about 95% O2.
The one I have, specs out a 5 liters per minute, cost me 800$ with a bottle refiller,
I don't have a conventional compressor,,, and haven't done the math, but with a small compressor and a VDF it should come close to making enough O2 for a stick,
Second what @grf88 said. They use adsorption via zeolites to remove the n2 for most of those systems. Also how they generate O2 in remote islands like Truk. Membranes can’t get to high enough O2 percentages.
I use an invacare oxygen concentrator fed into a stick but the pump has to be slowed to about 1cfm with a 5lpm concentrator. Not a problem with a VFD on a Rix but you can’t slow most oiled compressors down that much since they are splash lubricated. You could get a bigger concentrator or use multiples though.
 

broncobowsher

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You can also get the oxygen concentrator off of just about any Craig's list. When grandma passes away and there is no need for it anymore. With a little searching you can find a deal instead of someone looking at what was billed to insurance when it was bought new. The right one also has a tiny high pressure pump that will fill to about 2000 PSI. For refilling the portable bottles. But you can use a spare AL80 (or something like that) and make that an O2 bank for partial pressure blending. They are slow, but built to run unattended.

It isn't so much of an Oxygen concentrator but a Nitrogen remover. Argon gets concentrated as well. As mentioned, open circuit this is no big deal. A rebreather it is a little more of an issue. Your basic rebreather class will teach you about it. The really short answer is it messes up the ratio of inert gasses over time.
 

nadwidny

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I'm the IT guy for a fire department. I wonder if the standard they maintain is acceptable for SCUBA tanks.
Generally FD compressors are maintained as good as, or better than, compressors out in the wild in divers' care.
 

Tracy

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What about a Rix SA-6? Pumps ~ average 5cfm, doesn't use oil.... still crap in your opinion? Honest question, you know worlds more than I'll probably ever know.
I have very little knowledge about Rix compressors. A friend had one for a couple of years with minimal issues. All of my experience has been with recip compressors.
 

happy-diver

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Here's an ex fire department compressor, it's fast it's automatic it's beautiful
Tested and reconditioned, cost me about the same as a second hand Junior
I expect to change the oil repack the filter, never wear this unit out, for life

full


This rotary phase converter is what cost me, but brought pride and happiness
And cost a lot less than the cigarettes alcohol and tablets had I not been diving
You can see it up there on the floor next to the compressor behind some tanks

full



Quiet, ha you can conduct a spoken conversation next to it
Think of your tinnitus think of your future industrial deafness
Leave my compressor alone, you can almost leave the house

Buy big

Buy now when you can

And you too like captain can one day be the oldest with the oldest on ScubaBoard

Because you are all worth it!


And compared to all the other crap that people buy, a compressor costs absolutely nothing
 
https://www.shearwater.com/products/peregrine/

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