Balanced Regulators

[PToone]

Does size matter? haha

Really though, I am 6'5" and 230 lbs. Does that mean, since I'm bigger, that I may use more air? Or not a real big issue?

 

[Jorgy]

I won a FX10 - Delta 4 reg at a dive club raffle .......nice reg........

It will not double your bottom time.........

For SAC it is all about being completely relaxed underwater........

Another tip I read on a prior post, (TSandM I think) diving is about learning to float around underwater not the swim underwater.....

Think of everything in slow motion, easy slow deliberate movements.............

Don't use your hands/arms.......fold them across your chest......

The less time you can spend touching you inflator/deflator is better.......

Hope this helps......M

 

[dave4868]

Does size matter? haha

Really though, I am 6'5" and 230 lbs. Does that mean, since I'm bigger, that I may use more air? Or not a real big issue?

You're just sipping air! Yes, generally, bigger people are going to need more air.

Really, your air consumption is probably very good for your size.

Dave C

 

[PToone]

I won a FX10 - Delta 4 reg at a dive club raffle .......nice reg........

It will not double your bottom time.........

For SAC it is all about being completely relaxed underwater........

Another tip I read on a prior post, (TSandM I think) diving is about learning to float around underwater not the swim underwater.....

Think of everything in slow motion, easy slow deliberate movements.............

Don't use your hands/arms.......fold them across your chest......

The less time you can spend touching you inflator/deflator is better.......

Hope this helps......M

That is true. I was swimming around alot because there was a skills course down there. (the Homestead crater in Midway, Ut)

Thanks for the tips, everyone!

 

[RonFrank]

Does size matter? haha

Really though, I am 6'5" and 230 lbs. Does that mean, since I'm bigger, that I may use more air? Or not a real big issue?

Yes size DOES matter. Your a big guy, you have big lungs. You will likely never achieve the SAC rate of say, a 5'1" 110 lbs woman as you are over twice that size (weight), and will have much more of everything.. well except... boobs!

I have a good buddy that is about your height, and a bit heavier. On a typical dive he will blow through an AL100 and end up with less air than I do in an AL80. He may come up with 700psi, and I generally come up with 1200pis+, but depends. If I come up with less, so does he!

You may want to consider bigger tanks. There is no shame in having more air! As a bigger dude, a bigger tank may be more comfortable from a trim/buoyancy standpoint.

You could also consider something like a Steel HP100. They are about the same footprint as an AL80, but hold more air, and have better buoyancy characteristics. The are negative when empty. The only downside is.... price...

Good luck with the regs!

 

[rstofer]

We can't calculate your SAC rate without knowing five things: tank capacity, starting pressure, ending pressure, bottom depth and bottom time.

Guessing for an Al 80 and 2500 psi used in 38 minutes a SAC (surface air consumption) rate is calculated like this

CF (Cubic feet of air used ) = 80 * (2500/3000) = 67 cf
BT (bottom time in minutes) = 38
SAC rate (in cubic feet/minute) = CF / (((Depth/33) +1) * BT) = 67 / (((50/33)+1)*38) or 0.7 CFM

That's not a bad SAC rate, all things considered. Of course, if you were using an HP130, the results would be a lot different.

One of the nice things about smaller tanks, like the Al 80, is that it is very hard to get close to the NDL for most divers. It's kind of like another level of safety. Until you are very experienced, you won't have a low enough SAC rate to get in trouble. Note: this isn't necessarily a FACT but it's pretty close, most of the time.

Richard

 

[PToone]

We can't calculate your SAC rate without knowing five things: tank capacity, starting pressure, ending pressure, bottom depth and bottom time.

Guessing for an Al 80 and 2500 psi used in 38 minutes a SAC (surface air consumption) rate is calculated like this

CF (Cubic feet of air used ) = 80 * (2500/3000) = 67 cf
BT (bottom time in minutes) = 38
SAC rate (in cubic feet/minute) = CF / (((Depth/33) +1) * BT) = 67 / (((50/33)+1)*38) or 0.7 CFM

That's not a bad SAC rate, all things considered. Of course, if you were using an HP130, the results would be a lot different.

One of the nice things about smaller tanks, like the Al 80, is that it is very hard to get close to the NDL for most divers. It's kind of like another level of safety. Until you are very experienced, you won't have a low enough SAC rate to get in trouble. Note: this isn't necessarily a FACT but it's pretty close, most of the time.

Richard

Thanks, ron and rstofer.

I had an 80cuft steel tank. started at 2600PSI and ended with 600PSI my bottom depth was 50 ft for 38 min.

So I did 2000/38 = 52.6

(52.6 x 33)/(50+33) = 20.925.

Either way, I know this will get better in time. And, apparently, that my LDS claim of almost double BT on a balanced reg is BS.

Thanks for all your help/suggestions.

 

[redacted]

Your bottom time may well almost double in the future for similar dives. I'd estimate your SAC on the reported dive to be about .75. With more experience, you could well get your SAC into the .4 to .5 range. This should happen with or without a new regulator. Your dive shop is deceptive and not to be trusted.

 

[Jorgy]

When calculating SAC.........

Is it better to use average depth for the entire dive?

PToone......not sure if have dive computer that can calculate this for you?

M

 

[PToone]

When calculating SAC.........

Is it better to use average depth for the entire dive?

PToone......not sure if have dive computer that can calculate this for you?

M

I do have a computer to get the average depth, good tip!

Also, I forgot to mention that I am at altitude. I think that might affect it. I dove to 50 ft at an altitude of 6000+ ft. So I guess that equates to 70 ft.

Anyways, I'm glad you guys set me straight so I didn't blow $549 on the Delta 4 JUST for BT. I know its an amazing regulator, but I'll wait until I'm more experienced before I go for such a high quality reg.