A compressor system to grow with

[docscott19]

I am an instructor and I will be teaching for a scuba club at a university. The university does not have a compressor, so I will be supplying tanks for all classes. Based on current interest, it looks like I will be filling at least 400 tanks a year, and probably more once things really start going. I also dive enriched air and will teach it, so that it is about 200 tanks a year for enriched air. Finally, by the end of the year, I will be trained in Trimix so would like to be able to eventually make my own.

My question is, what is the best system for my needs? I will be putting this in my basement or garage. Based on the prices my LDS charges, it would cost me at least $8000 a year for the above fills. Any help would be greatly appreciated. Thanks.

 

[pickens_46929]

I am an instructor and I will be teaching for a scuba club at a university. The university does not have a compressor, so I will be supplying tanks for all classes. Based on current interest, it looks like I will be filling at least 400 tanks a year, and probably more once things really start going. I also dive enriched air and will teach it, so that it is about 200 tanks a year for enriched air. Finally, by the end of the year, I will be trained in Trimix so would like to be able to eventually make my own.

My question is, what is the best system for my needs? I will be putting this in my basement or garage. Based on the prices my LDS charges, it would cost me at least $8000 a year for the above fills. Any help would be greatly appreciated. Thanks.

Contact the folks over at Breathing Air Systems as a starting point... even though you fill 400 tanks a year, it's more critical to figure out how many tanks you'll need to fill at once and whether you should cascade or not.

In my neighborhood there wouldn't be an issue with me running the compressor non-stop for 24 hours or so. In my old neighborhood, that wouldn't have gone over so well even with some sound proofing I still would have had issues with the neighbors.

Look around for a dive shop that is going under and see if their compressor is worth buying. Look around your local area for another diver that already has a garage setup and might want to expand (eg. you buy a cascade system and share the fill station with him). You might be surprised how many home garage fill stations there are around.

Dave

 

[KOMPRESSOR]

Make sure you don't even try to put a cascade on any small portable compressor anyways. They're meant for filling one tank at a time, and then pause for a while.

You do need a compressor meant for heavy commercial use. You might find some of them rather expensive, but if you're a technical vizard you can easily rebuild one on the small Bauers from the late 70's, fit a new filtersystem, and have plenty of hours on it on a small budget. I've fitted 2x80 litres 300 bar storage tanks to mine, making speedy air fills a breeze.

 

[Hoosier]

Make sure you don't even try to put a cascade on any small portable compressor anyways. They're meant for filling one tank at a time, and then pause for a while.
.

Alkin (3.5 CFM) does a great job for a cascade. :mooner: The most important concerns are an auto drain and good filtration system for a cascade...


400 fills per year isn't overload at all. I used to fill around 200 tanks per year without cascade set up. Get an electric, not a gas powered compressor. It is much quiter.

 

[daniel f aleman]

Try 200 fills per week over nine months!

The best that you will be able to do (in the short term) is to make a deal with the local shops, be willing to spread your business around if necessary. Let them know that you'll have ~400 tank fills, and let them bid a price for you. (I teach scuba a my local university, and this is the way we do it - we pay $2.00 per air fill for an AL80.)

You should be able to work tax write-offs on the costs, much easier if you purchase your fills from a third party.

And, you have to figure in overhead costs, your time, training costs, and any liability that might come your way IF there were to be problems and/or accidents derived from yur actions as the tank filler.

Otherwise, you need to buy a third party manufactured dedicated gas fill system set in its own place. You need to be trained to operate the system, and you need to be FULLY insured for liability.

 

[KOMPRESSOR]

Alkin (3.5 CFM) does a great job for a cascade. :mooner: The most important concerns are an auto drain and good filtration system for a cascade...


400 fills per year isn't overload at all. I used to fill around 200 tanks per year without cascade set up. Get an electric, not a gas powered compressor. It is much quiter.

I don't know the Alkin 3.5. Is it portable, as possible to carry, one man alone? That's what I meant anyways. My old Bauer is hardly portable and delivers only 4.0 CFM, even though I've tuned it up a bit. But it has massive goods to distribute heat, and great cooling too.

The main concern isn't autodrain for long hours as you can get or make that on any compressor. -It's cooling. And if you don't know that, go moon yourself!

 

[The Curly One]

I sell the ALKIN compressors and yes our small one can fill cascade systems I recommend the larger W32 8 CFM compressor for several reasons. To correct one guys statement here cooling is not and issue with the W31 compressor you can run it 8hours non stop if you want. I still think the larger compressor is a better choice for any commercial use or any time you are providing life support for others.
1. (Most important!) The W32 has a MUCH larger filtration. All portable compressors have small filters to save size, weight and cost. ALKIN 3.5 and Bauer are exactly the same size filters, there is one brand out there with a final filter about half that size!
2. He stated he will probably be growing in the future so might as well buy one compressor that will fit his needs for years to come. (My opinion) Also when word gets out you have a compressor you get all kinds of new friends who need air.
3. In the long run once you consider maintenance and filters the W32 will come out at a lower cost per fill.

As they say different horses for different courses. If you are looking for a portable compressor for just filling your own personal tanks then there are 2 good brands out there. If you are providing air for others then a larger compressor would be a better choice.

 

[Hoosier]

If then, your initial post was vague.. You said exactly.....

Make sure you don't even try to put a cascade on any small portable compressor anyways. They're meant for filling one tank at a time, and then pause for a while.

My point was Alkin CAN DO a good job for a cacade set up. There are many members who have a cascade with an Alkin portable one on the board.

I don't know the Alkin 3.5. Is it portable, as possible to carry, one man alone? That's what I meant anyways. My old Bauer is hardly portable and delivers only 4.0 CFM, even though I've tuned it up a bit. But it has massive goods to distribute heat, and great cooling too.

The main concern isn't autodrain for long hours as you can get or make that on any compressor. -It's cooling. And if you don't know that, go moon yourself!

Again, I can't follow your post. Now, you are talking about a portable design.

Alkin is about 130lb as I recall. It has only two wheels. I have never tried to lift it, but I put two more wheels and am able to haul it. So, depending on your perspective, it is a portable.


We aren't talking about a compressor in general here. but about a cascade set up that you brought in your previous post. Heat is generated no matter what you do as long as you are running the compressor. Therefor, heat/cooling is out of another considertation category because it is a fundamental concern/factor we have to deal with from the begining when we have a compressor.


Hence, in reality, an auto drain and big filleration are most important concerns to run a cascade. the genuine filteration on any portable compressor only lasts about 10~15 hours in most humid environment (even mid-west), so it is NOT enough for a cascade and nobody wants to drain every 10~15 min for 8 hrs running. That's is my point.


I have an individual fill station and fill about 200 tanks (mostly HP double tanks) per year as I said earlier. If Alkin was the compressor for "filling one tank at a time, and then pause for a while," nobody woudn't spend more than $4000 for it.

Just my 2 bar.

 

[Isaac-1]

Having worked as an instructor (although it has been several years since I taught) and a person that owns a small compressor (3.4 CFM portable), I am going to make a few assumptions about your needs. First that most of your classes are Open Water, if your classes are full and you are doing the typical single pool session per day, and 4/5 certification dives on a weekend at a location near enough that you could refill tanks each day, with 8-10 students and an assistant, so say 12 tanks fills at a time per pool session, plus at least another 24 at a time for open water certifications dives assuming no time to fill between dives each day. I will not go into detail addressing the nitrox issue other than say as you likely know there are two popular ways blend nitrox Partial Pressure and Continous blending, with as it seems a growing trend towards Continous blending even for small installations. From an air point of view I see little or no advantage for you in having a large air bank, as the prime advantage of such a system is to time shift the need to run a compressor (remember both air fills and compressors need near constant supervision while running) and make it much easier when you only need to fill 1 or 2 tanks, instead if your on a budget I would suggest an older Bauer compressor (or system using a Bauer blcok like many Mako's etc) in the 15+ CFM range probably adding multi-stage filtration, as parts are generally available and a small 1-2 air + 1-2 Nitrox tank fill bank with a multi fill manifold that allows you to parallel fill 6 tanks at a time. Filling 6 tanks at a time staight from the compressor would allow for nice cool 20 minute fill times and fill all the tanks you need for an open water pool session in under an hour, 20 minutes is also about the time interval when you would need to purge the drains if the compressor does not not have auto drains. This set up would also allow you to leave the compressor running while switching out batches of tanks by simply redirecting the air to top off your air bank.

Ike

p.s. I would think PP or CB blending into a 6 tank manifold system would run much the same as filling into an equal sized bank, but I am not an expert.

p.p.s. Deals on these older heavy mid size compressor can often be found on ebay, the prices tend to be about 25% lower in the winter off season, often they sell for not much more than the price of a lightweight portable.

 

[Aqua Marine]

I have a 15 cfm portable compressor on Ebay right now (280140433361)

Bid is less than $800, if you have a little time to put in it might be worth looking at.

I also have a Bauer K14 electric if you are interested in something more versitile. I run a 10,000 cf bank off a Bauer K14 now. Continuous flow and PP blend, very quiet & would not bother the neighbors...