How much should an airfill be?

[triplecove]

Well thank you for all the input with all you help this is what I come up with sorry if it is a little "fuzzy" I am just trying to mak an informed decision!

Tell me if my math is wrong this is based on the $8.75 I have been paying for the last couple of years for fills :
Compressor $3154.95
Shipping 311.95
Filters for 5 years based on 150 fills per
Year max air says you get 30-50 fill per
Filter we’ll say 40. 20 filters@49.95 999.00
Service on compressor : holds 12oz oil
1^st 12oz comes w/compressor 1 gal
Is enough for 10 more compressor
Oil changes 2 changes per year 105.95
Electricity about $.6063 per hour at $.1471 per kwh
230v electric motor uses 4.3kw to run 3 fills per hour
$.22 per fill * 5 years worth 165.00
Total cost $4736.85 750 LDS fills= $6562.5 @8.75
Divide by 750 fills $6.31 per fill after 5 years
10 year cost per fill total cost $6006.80 $4.00 per fill (1500 fills in 10 years) LDS cost $13125.00
10 year savings $7118.20
It looks to me like the finding a dive shop that still does $5 fill cards might be the way to go.
Max-Air | High Pressure Air Compressor, scuba air compressor, paintball compressor

 

[meagicano]

My LDS is very reasonable - $7.50 per fill (32% Nitrox or air) with their 10 fill air cards. I think they charge $10-12 without the card. If you buy their annual dive club membership (which comes with a t-shirt and discounts) for $40 you also get a free fill card. So your first ten fills of the year would be $4 each.

 

[triplecove]

I am told there is a place in Weymouth Ma. (not too far from me) That still does air cards I am going to go see those guys soon. It is farther than I usually have to go but the fills might be significantly cheaper. Its a shame I really like the people at my current dive shop it is just tough to swallow when I bring in 6-8 tanks at a time at a cost of 50-72 bucks when at other locations are 30-40 with an air card. I dont have any experience with Nitrox but that sounds like a great ($7.50) deal from what I have read.

I still wish I could get in contact with someone who owns their own Max air35 so I would have more concrete numbers on the cost.

 

[chrpai]

Have you tried negotiating with them? There might be wiggle room.

 

[spectrum]

Well thank you for all the input with all you help this is what I come up with sorry if it is a little "fuzzy" I am just trying to mak an informed decision!

Tell me if my math is wrong this is based on the $8.75 I have been paying for the last couple of years for fills :
Compressor $3154.95
Shipping 311.95
Filters for 5 years based on 150 fills per
Year max air says you get 30-50 fill per
Filter we’ll say 40. 20 filters@49.95 999.00
Service on compressor : holds 12oz oil
1^st 12oz comes w/compressor 1 gal
Is enough for 10 more compressor
Oil changes 2 changes per year 105.95
Electricity about $.6063 per hour at $.1471 per kwh
230v electric motor uses 4.3kw to run 3 fills per hour
$.22 per fill * 5 years worth 165.00
Total cost $4736.85 750 LDS fills= $6562.5 @8.75
Divide by 750 fills $6.31 per fill after 5 years
10 year cost per fill total cost $6006.80 $4.00 per fill (1500 fills in 10 years) LDS cost $13125.00
10 year savings $7118.20
It looks to me like the finding a dive shop that still does $5 fill cards might be the way to go.
Max-Air | High Pressure Air Compressor, scuba air compressor, paintball compressor

Nice collection of facts. It makes an excellent case for dive shops to charge ~$8.00 per fill, they are in business afterall.

It assumes no repairs which may or may not be a safe assumption.

The time you spend handling it should easilly be favorable to going to the dive shop so unless you are distant it's safe wash.

It assumes long term intense diving however you do have the "out" of selling it off for decent recovery.

Pete

 

[triplecove]

Nice collection of facts. It makes an excellent case for dive shops to charge ~$8.00 per fill, they are in business afterall.

It assumes no repairs which may or may not be a safe assumption.

The time you spend handling it should easilly be favorable to going to the dive shop so unless you are distant it's safe wash.

It assumes long term intense diving however you do have the "out" of selling it off for decent recovery.

Pete

Agreed

 

[clownfishsydney]

The specifications for the Max Air 3.5 say that it fills to 4800 psi. Therefore it should easily and safely fill to 3300 psi.

The 240 volt electric motor should be rated at about 2.2 kw, not 4.3 kw (I cannot find the specs anywhere on the web, but Bauer and Coltri are this). Therefore electricity will be about half what has been calculated.

Synthetic oil (make sure you only use this - never use mineral) probably only needs to be changed once every 2 years. It certainly does not need to be changed twice a year.

You should get more fills per filter. They normally quote based on worse case senario. It is easy to work out a table that enables you to calculate the filter life used per fill based on air temperature, size of tank and how much air is still in the tank. Bauer quotes 26 to 32 12 litre tanks at 20°C and only 15 to 19 12 litre tanks at 30°C (100 cf tanks at 68F and 86F). This is filling from empty. In reality, I get about 90 to 100 tanks and when opened, the filter still has considerable unused proportion of molecular sieve.

Have a look at my web site page on my filter Michael McFadyen's Scuba Diving Web Site and email me if you have any questions.

 

[triplecove]

Thanks Clownfishsydney These are the real world numbers that I did not have access to. I got the kw rating from a similar 3hp electric motor, and I also figured that you could get a lot more fills per filter(again no experience to know for sure) but I could not find a service interval for the compressor oil so I gave a conservative guess(way off I see). So thank you for your info. When I have time I may do a few recalculations and post the results.

And wow That is an incredible resource you have there in your website! I would recommend reading it to anyone thinking about buying a compressor.

 

[drbill]

Of course the volume a dive shop does each year will affect per fill costs. The expensive compressors have to be amortized within the cost structure. Here on Catalina air fills are $7 although that can be brought down to about $6 with an air card (10 or 20 fills depending on shop). Back in the 70s the school I taught at had its own compressor (courtesy of William Conrad of "Cannon" and "Jake and the Fatman" fame since his son was one of my students) and I wish I'd had more time to dive then.

 

[Ana]

Here is another reason why I enjoy South Florida so much. I have Fill Express about 2 miles away and they don't charge by "the bottle" they charge by the cubic foot so it doesn't matter what you use. No particular type of tank gets penalized by getting charge extra due to "Perceptions" from the shop owners.

I forgot what it actually comes to be for each of my tanks, we buy 1000 cubic feet at a time, and never feel ripped off when I go in with one of my hp tanks that has 1800 psi left from the previous dive.