Is the air on this 12v hookah system safe to breath?

[Kharon]

What I can't figure out is the almost 100% feedback...

The feedback may be totally bogus.

 

[GiantMoray]

That contraption looks pretty scary!

 

[tech_diver]

I remember this thing from the thread last year. I can’t believe it’s still out there.

When a person is hurt or killed on a rebreather and the liability case goes before the court, the manufacturer has to defend their RB design on a technical level. Experts are brought in to question O2 sensor voting logic, scrubber design, training standards, everything. I can’t imagine anyone trying to defend this device in a court of law.


When this thing fails such that a person gulps seawater and pops to the surface from 6-7 feet down, it could result in some type of expansion injury. What would the builder of this contraption tell the court?

Would they bring in their expert witness to testify, “Our state of the art design incorporates a high tech hose securely stuck in the end of a snorkel connected to an aquarium pump. Its failure is something that no reasonable person could foresee.”

 

[letsurf]

I wish I had started this thread before I purchased that unit. Received it in the mail and hooked it to to give it a test drive. It didn't even put out enough air for me to take a full breath above water. When I tried to breath in fast to catch my breath the regulator was stopping the breath in (I'm assuming because the preasure/flow wasn't enough to keep up. Can't imagine struggling to get air at 15" so I sent it back for a refund.

Talked to a local dive shop and signing up for a beginner scuba class. Now I'm in the market for a quality 12v system that will support 2 divers to 15' depth. The most important factors are:

Run time (the less amperage the better. I think a 30amp system might be overkill.)
Quality compressor
Price ($1,500 or less)

Trying to decide between the following:

jsink Air Line
Keene Engineering Hydroair
Hookamax
Brownies third lung

Any ideas on which system would be the best for me?

 

[Rich Keller]

First take the course and get certified before you do anything else. How are you planning on using this? What type of dives are you going to use it for? Another option would be to splice 50' of hose between your first and second stages so you could use existing scuba equipment to dive surface supplied. That way you can spend the $1,500 on scuba equipment that you can use for both scuba and surface supplied diving.

 

[letsurf]

First take the course and get certified before you do anything else. How are you planning on using this? What type of dives are you going to use it for? Another option would be to splice 50' of hose between your first and second stages so you could use existing scuba equipment to dive surface supplied. That way you can spend the $1,500 on scuba equipment that you can use for both scuba and surface supplied diving.

View attachment 164818View attachment 164819

I'll be using it to dove freshwater rivers and lakes to about 10-15' deep. I don't have a need for scuba diving to 50+ feet and I think the 12v system would be more convenient. I don't want to mess with getting tanks filled all the time. With a 12v system I can just charge the bats in the garage and be off whenever I want.

 

[CT-Rich]

The feedback may be totally bogus.

People lying on the internet?!? I won't believe that!!!!

---------- Post added September 6th, 2013 at 07:37 PM ----------

[video=youtube;x8f_87UaXtE]http://www.youtube.com/watch?v=x8f_87UaXtE[/video]

This is really looks like dangerous piece of crap.... I could see an uncertified diver trying to mine gold with this. If he doesn't drown immediately, he will hurt his foot kicking this POS down the road. If you did use it you are probably going to end up dying from a lung infection from moisture laden crap and plastic residue that will start growing in hose in short order. I would be scared to pick up golf balls with this rig. The video is kind of enjoyable (if you haven't pay $315). Love the way the diver can't even get his ass underwater with this rig. My condolences to the OP, I hope you get your money back.

 

[letsurf]

People lying on the internet?!? I won't believe that!!!!

---------- Post added September 6th, 2013 at 07:37 PM ----------

[video=youtube;x8f_87UaXtE]http://www.youtube.com/watch?v=x8f_87UaXtE[/video]

This is really looks like dangerous piece of crap.... I could see an uncertified diver trying to mine gold with this. If he doesn't drown immediately, he will hurt his foot kicking this POS down the road. If you did use it you are probably going to end up dying from a lung infection from moisture laden crap and plastic residue that will start growing in hose in short order. I would be scared to pick up golf balls with this rig. The video is kind of enjoyable (if you haven't pay $315). Love the way the diver can't even get his ass underwater with this rig. My condolences to the OP, I hope you get your money back.

I sent it back and got a full refund. The seller said he tested it and there wasn't anything wrong so I guess it was normal to not be able to take a full breath with the unit. Decided to go with the Keene Engineering HydroAir. At least the HydroAir was designed by the engineers at Keene so hopefully it's better quality and safer.

 

[Rich Keller]

This still sounds like a bad idea but if you are determined to do it what you need to look for in a compressor is how many cubic feet of air it can make per minute and at what psi. For fresh water you need to add .432psi per foot of depth over the ambient pressure of 14.7psi just to break even. So in 15' of water you need a compressor that will produce at the very least 50psi but more would be safer. The compressor will also need to produce that pressure at a high enough rate of cubic feet per minute to keep up with your breathing rate. If you breath 1 cubic foot of air per minute at rest on the surface you would need the unit to make 2 cubic feet of air per minute per diver at 15'. So you would need a unit that can make at the very least 5 cubic feet of air per minute but 10 or more would be safer. You would also need to have the second stage adjusted to operate at a lower pressure as most are made to operate at over 100psi being delivered from the first stage. The other thing you would need is a volume tank so the air is delivered to you smoothly at a constant psi and will act as a small reserve if the compressor fails. This would need to be able to handle at least twice the pressure that the compressor can deliver but again more would be safer. Something like a small beer keg could work if it can handle the pressure and you could rig it right. Even if you do get this set up right you would still want to carry a reserve of air with you on the dive, something like a Spare Air should be enough for a 15' dive. Spare Air - the smallest redundant SCUBA system available with enough air to get you to the surface in an out-of-air emergency. The other thing you need to consider is how long the battery can run the compressor effectively. If it is not going to be that long then I think you would still be better off using a scuba tank and reg with about 50' of hose spliced between the first and second stages. There is far less that can go wrong with the scuba tank setup then a compressor setup like the one you are considering.

 

[BRT]

The problem with 12 volts is the insane amount of amps required to get any power out of it! 1 horsepower is 746 watts. at 12 volts that is 62 amps before you factor in efficiency. Reality is it usually takes close to 1000 watts input to produce 1 hp. That's 83 amps. Realistically that 1 hp will give you 1-2 cubic feet per minute. At a 1cfm breathing rate an AL80 will last you 77 minutes to empty. In other words 1hp might produce enough air to breath. How are you going to carry enough batteries to last any time at 83 amps draw? This is the reason gas engines are used for hookahs.