Compressor recommendations for home / club use

[CAPTAIN SINBAD]

Fellows: A few of us are considering chipping in and purchasing a compressor for local diving and fills etc. We are not a diveshop so nothing fully commerical is needed. Anything that could fill 20 tanks / week should be good enough. Any one has any suggestions for something slightly more powerful than the basic portable 3500 USD stuff but not the monsters we see in LDS?

Any and all suggestions welcome!

 

[Doppler]

Look at something portable, and budget for a couple of high-pressure, high-volume storage tanks. Should you want something compact and reasonably mobile, you might check out http://www.alkinusa.com/images/xlg_w31honda.jpg I'd also strongly recommend investing in a good gas quality and content sensing system (look at what ANALOX offers).

Important, if you are going to house this in a shed or basement or garage, that you know WTF you are doing regarding intake, elimination of moisture, temperature control.

 

[CAPTAIN SINBAD]

Look at something portable, and budget for a couple of high-pressure, high-volume storage tanks.

Makes sense! Any idea how much these would cost?

 

[redacted]

Makes sense! Any idea how much these would cost?

Some operating cost info I found interesting:

[SIZE=+1]COSTS[/SIZE]
Running Costs - After 3,423 fills completed at 3 December 2013 - 1088.02 hours and before any fills on a new filter

Item	Cost per fill since new	Repackable filter cost	Latest filter cost
Filter	$0.30	$0.17	$0.09
Electricity	$0.11	$0.13	$0.21
Oil	$0.03	$0.04	$0.05
Spares/repairs	$0.10	$0.03	$0.04
TOTAL	$0.54	$0.37	$0.38

1. NOTES:
2. The nipples and valves purchased have been amortised over a number of filters
3. The oil has been amortised over a number of filters and not all the cost has yet been reflected in the fill cost but the above represents a realistic situation.
4. Repackable cartridge will be amortised over fills 14 to 66 and included in Filter cost.
5. The cooling pipes between second and third stage will be amortised over fills 41 to 90.
6. The electricity cost has gone up markedly in recent years and also I have been filling a friend's tanks which are larger and more empty than our own

Fixed Costs
At the same time as above the purchase cost of the compressor is $1.48 per fill. This is basically treating the compressor cost as 100% depreciated.
Total Cost
The total cost as I write this is $2.01 a fill (over the life of the compressor) and since using replaceable filters it is $1.85 a fill. Therefore, based on $9 a fill (or even $5) we are already ahead and of course this will get even better over the coming years. This also does not take into account the return we would get today if we sold the compressor.
As of 5 February 2014, Kelly and I have saved $12,510 based on airfills costing $7 each.



From this site: Michael McFadyen's Scuba Diving Web Site

Please keep posting on what you learn. Thanks

 

[tbone1004]

those hp banks are wildly different prices based on availability and new/used. The 4500psi+ones are hard to find. If you're planning on filling all 20 at once and they are HP steels, you'll need at least a 10cfm compressor with 4 banks, that's a lot of gas to fill especially to high pressure. Rix SA-6 will keep up with most of it but it isn't going to be a land speed record. Keep in mind with anything larger than that, if it is electric it will likely be on 3-phase, so lots of stuff to go into the calculations.

 

[Herb-alaska]

First my recommendation would be a max air 35 I have one and love it. I am moving up to a max air 90 for a couple of reasons. 1. I got a great deal from a closed up shop and 2 there are busy times when my max air 35 needed help keeping up. The max air 35 would have no problem unless you plan on filling 20 tanks on the same day. If you are looking for 3 to 4 tanks a day no problem it will handle that nicely.

Now on sharing a compressor. My suggestion is DON'T DO IT! I would relate the likelihood of successfully sharing a compressor with a group of dive buddies and having everyone stay friends is equal to the likelihood of successfully sharing your wife. In my opinion it is not going to work. Everyone cares for things differently and compressors that are cared for last a looooong time and compressors that are not cared for get expensive really quick


my 2 psi
Herb

 

[nadwidny]

I would look at something rated for around 7-9 cfm (somewhat portable and still only requiring single phase power) with 3-4 of the 4500 psi cascade cylinders. I find with my compressors of that size it take about 1 hour of running per 1000 psi into the banks. When I had just 4 of the HP cascades I think I could fill around 12 tanks without starting the compressor.

 

[manni-yunk]

Having a compressor is one of the best things I ever did (now I have 2 - with one on the boat).


THe compressor I bought for my home (8.4 cfm bauer) came as a package with 12 4500 bank bottles and I will likely sell 4 of them early next year.

 

[seaseadee]

AWAP,
shouldn't also you include the cost of depreciation of the compressor and perhaps opportunity cost of the dollars spent on the compressor? After all, you did spend money on it.

 

[victorzamora]

AWAP,
shouldn't also you include the cost of depreciation of the compressor and perhaps opportunity cost of the dollars spent on the compressor? After all, you did spend money on it.

He did include depreciation of the compressor, and did so more aggressively than necessary. He fully depreciated it, which is more expensive per fill than a more accurate calculation. I mean, I'd pay him $100 for that compressor setup right now....so it clearly doesn't have zero value, which he did assume. . That was the $1.48 value.

As for opportunity cost, it's REALLY hard to calculate that. What would you do, assume 8% in a growth stock mutual fund? Or index it to DJI and look at what it could've grown to?