Home Nitrox System

[UaVaj]

At $10 a fill for nitrox. I'd average about 2-4 tanks a week. If I did own a compressor and with my dive buddies - that average would be about 9-12 tanks a week.

The motivation: I am not too concern about the $10 per fill however I refuse to fill air/nitrox at my most convenient LDS which is only a 1/4 mile detour from my every day route. That shop is a scumbag. They won't get a penny more of my money and I hope they go out of business. The next LDS is 12 miles one way through city traffic. That is just too much time invested driving through traffic just to get my tanks filled.

Depending on the cost of the compressor. I think I/we are better off buying our own filling system. What are cost associated with owning our own pump. Maintaince? Filters? Electricity/Gasoline (fuel)? Oxygen Tank? What else?

Any compressor dealer. Feel free to contact me.




At the moment - I am not even sure if this is the right stuff or what to look for in a suitable Nitrox filling station? I am sure there are pleny of other alternatives. However here is what I am considering.

http://cgi.ebay.com/New-High-Pressure-Air-Compressor-Paintball-Scuba_W0QQitemZ150152341801QQihZ005QQcategoryZ10554QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

http://cgi.ebay.com/AireTex-Basic-Jr-Nitrox-for-SCUBA-Air-Compressors_W0QQitemZ150152828184QQihZ005QQcategoryZ1300QQssPageNameZWDVWQQrdZ1QQcmdZViewItem




As I am thinking more about this - to be extra safe. Maybe I should consider the membrane type nitrox filling station so I don't have to mess with pure 02 at all. Are those even more $$$.

Or mabye should I just invest this money into a rebreather instead?

 

[bigchrisb]

Hi,

I mix my own nitrox at home through a bauer K14, and a home made mixing stick. Before you go down this route, I'd suggest you do your research. Web forums are a good start - there is lots of info on scubaboard, and some of the other more technically oriented forums. I'd also suggest that you invest in a copy of the oxygen hackers companion from airspeed press - it was the single most useful rescource for me in setting up my system.

In terms of ongoing costs, expect filtration, energy, lubricants and compressor maintenance to be non-trivial. For me, it doesnt represent the best business case (I probably have about $12k into my system), but it does represent great value in convinience, in having gas at my fingertips, at the mixes and pressures that I want, when I want!

Good luck, and spend lots of time researching before embarking on the project. My preference is to stear clear of the little coltri compressors (that's the type of block used in the maxair). But having said that, I run two bauer compressors, that many would regard as commercial grade rather than recreational machines. Its a bit of a choice between size, weight and fill speed. If you don't need a portable system, I'd suggest getting a mid-size compressor with a slow rotational speed, rather than one of the tiny portables revving at 2000RPM+ too fast in my opinion.

 

[DennisS]

If I had lots of money I'd go with a membrane system. I've used one onboard the ship for months at a time without any problems.


These guys are really helpful

http://www.nuvair.com/shopsite_sc/store/html/nitrox_sport.shtml

The EPA Ship Bold uses the larger of the portable systems listed at this site, don't forget you need a LP compressor to supply it
http://www.dnax.com/

 

[skippy31]

There is not really much difference in how the membrane system and the nitrox stik generate nitrox in the sense that both systems take nitrox up to 40% and run it through a compressor to generate the high pressure nitrox we breath.

The big difference is in how the two systems generate the low pressure nitrox. The membrane requires several thousand dollars of membrane system along with either an oil free low pressure air source, or a cascade system with a regulator to drop the pressure to something useable by the membrane system (around 200 psi or so). The membrane then dumps some of the nitrogen out of the gas and generates nitrox by "concentrating the O2".

The nitrox stick uses $100 in parts to generate nitrox by mixing O2 with air. Bascially with this system a regulator on an O2 tank mixes O2 with air as it goes into the compressor.

In both approaches HP O2 is not used to generate the nitrox as it is in partial pressure blending.

The difference between the two systems from a cost standpoint is that the membrane has a high initial cost but then there are lower running costs. The stik requires you to have HP O2 on hand to feed the system (through an O2 regulator)

For any low volume usage there is no question that the stik appoach is the winner in terms of cost. You need to be generating a ton of nitrox to justify the additional cost of the equipment and maintenance of the membrane system.

For almost all home use the cost of the membrane system would not be justified.

Skippy31

 

[Scuba Duck]

See the following link for a description of how the different methods work. There is a spreadsheet there that breaks down the costs associated with the different methods.

http://www.nitroxmadeeasy.com/Methods.htm

 

[oxyhacker]

You can sweeten the number for a continuous mixing considerably by using a <$200 DIY rather than a $2300 Stik!

See the following link for a description of how the different methods work. There is a spreadsheet there that breaks down the costs associated with the different methods.

http://www.nitroxmadeeasy.com/Methods.htm

 

[pescador775]

Here is an useful article relating to costs of ownership:
http://scubafrum.org/cgi-scuba/akcs-www?post=9

Insert an "o" into "forum" and paste into your browser. Sorry for the inconvenience

 

[UaVaj]

I just got my tanks filled today. 45min there, 30min wait (wasn't a busy day), 45min back. Most of the time is. 45min there, 5min drop off, 45min back, next day, 45min there, 10min pickup, 45min back. What a PIA.

I am definitely gonna get my own compressor.

Not sure which brand or model? and not sure if better preowned or new?

Order of importance.
(1) Super Reliability
(2) Low Maintaince
(3) Low Operating Cost
(4) Good Performance
(5) Initial Equipment Investment Cost

 

[Scuba Duck]

I took the information from Pescador's link and put it into a spreadsheet. It's tailored more for the commercial dive shop with a larger compressor, but you can edit the parameters highlighted in yellow for your compressor, cost of electricity, etc.

http://www.nitroxmadeeasy.com/Documents/TankFillCostSpreadhseet.xls

Let me know if I missed anything glaring...

 

[UFG8R]

I just got my tanks filled today. 45min there, 30min wait (wasn't a busy day), 45min back. Most of the time is. 45min there, 5min drop off, 45min back, next day, 45min there, 10min pickup, 45min back. What a PIA.

I am definitely gonna get my own compressor.

Not sure which brand or model? and not sure if better preowned or new?

Order of importance.
(1) Super Reliability
(2) Low Maintaince
(3) Low Operating Cost
(4) Good Performance
(5) Initial Equipment Investment Cost

I'm right there with ya. The membrane systems are just too expensive. The Nitrox stik system with controller looks relatively simple and seems like a good way to go. Is there any consensus on what the best system for home use would be?
Heck, I have to tack on an additional 6.00 in tolls to get my fills....No more! No more.

Keep us updated on what you find and where to buy.