ScubaDan
October 6th, 2002, 04:23 PM
I know what nitrox and trimix is but what is Hotx?
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ScubaDan October 6th, 2002, 04:23 PM I know what nitrox and trimix is but what is Hotx? Ontario Diver October 6th, 2002, 04:33 PM Dunno...... Is it one of those $29.95 per month websites?:D voidware October 6th, 2002, 04:47 PM High Oxygen TrimiX. It is for those who want to dive in depths less that 180fsw (still in >21%02) with out narcosis and the benefits of higher fO2. There are various other names for this as well. brandon detroit diver October 6th, 2002, 06:11 PM Brandon, What PO2's do these people usually dive when sucking HOTX? Max depth on 32% is 111ft. How high do they run the O2 percentage? reefraff October 6th, 2002, 06:40 PM Which means I have no idea what the answer is and wish I did... detroit diver once bubbled... Brandon, What PO2's do these people usually dive when sucking HOTX? Max depth on 32% is 111ft. How high do they run the O2 percentage? Hmmm. EAN mix already reduces your END by replacing nitrogen with oxygen, or do you call oxygen and nitrogen narcotic effect equivalent and use the helium to... Uh, oh, I may learn something today. Steven. ScubaDan October 6th, 2002, 06:50 PM The reason I ask was because I was at the abysmal diving web sight and watched the intro and one of the gases that was used on the simulated dive to 330fsw was hotx. Thanks for the help. http://www.abysmal.com/english.html I think it's a net intro voidware October 6th, 2002, 07:43 PM The MOD for EAN32 is 130ft. If you are trying to keep your END to less than 100ft. I could see it more in 28% (~150) Putting helium in your mix will reduce your narcosis levels enough without putting too much helium and increasing decompression obligations. As for using HOTx for a 330fsw dive, it could be a dilutent in a rebreather. I haven't been trained in any of this stuff, so I don't really know how it is actually used, just in theory. Brandon ScubaDan October 6th, 2002, 08:25 PM If you didn't watch the intro the hotx was only used at the start of the dive and they switched to trimix they went deeper and then on the way back up they again used hotx. omar October 6th, 2002, 09:06 PM We routinely use 30/30 which is sometimes considered HOTx. I prefer it to 32% EANx. It can also be dove with nitrox computers (horrors ;-) set to 32% as well. omar detroit diver October 6th, 2002, 09:07 PM voidware once bubbled... The MOD for EAN32 is 130ft. If you are trying to keep your END to less than 100ft. I could see it more in 28% (~150) Putting helium in your mix will reduce your narcosis levels enough without putting too much helium and increasing decompression obligations. As for using HOTx for a 330fsw dive, it could be a dilutent in a rebreather. I haven't been trained in any of this stuff, so I don't really know how it is actually used, just in theory. Brandon Yes, you're correct on the MOD as 130. I use a max PO2 of 1.4 which put MY MOD as 111 ft. Sorry for the confusion. reefraff October 6th, 2002, 10:18 PM omar once bubbled... We routinely use 30/30 which is sometimes considered HOTx. What is your definition of HOTX and when would 30/30 not be considered HOTX? I prefer it to 32% EANx. Why? I haven't done the math on this, but doesn't reducing the N by 11% in the mix substantially improve the END? What advantages does adding this much He to the mix offer? Beyond price, reduced non-deco limits and R values, what disadvantages? It can also be dove with nitrox computers (horrors ;-) set to 32% as well. What is the formula used to arrive at this 30/30 = EAN32 equivalency? Thanks, in advance! Steven Uncle Pug October 6th, 2002, 10:29 PM We use 30/30 for dives to 120' We subtract 15% for our EAD. We reckon oxygen the narcotic equivalent of nitrogen. We actually suspect that it is more so. At least it *feels* that way. omar October 7th, 2002, 12:32 AM I don't have a definition for HOTx. I don't worry about it. I have been moving to a set of standard mixes for my dives. The EANx has been relegated to places I can't get He or warm water, high viz, fish dives. ummm taking 30% of the N out is better than offseting it with the added O2. Both are considered to be narcotic. By R values I assume you mean thermal properties. There is no significant difference between air and 30/30 as far as thermal properties for breathing. The higher thermal conductivity of He is offset by the lower heat capacity so the sum is about even when comparing heat loss from breathing. I actually went through the math on one of the threads a long time ago. The helium mix actually had a SLIGHTLY less heat loss. As, I said you can actually dive it as 32% EANx on the Alladan dive 'puters. So in effect there is no NDL disadvantage for single tank dives. Running lots of scenario's on dive planning software and experience has found that this works for me. omar AquaTec October 12th, 2002, 01:12 AM ScubaDan once bubbled... The reason I ask was because I was at the abysmal diving web sight and watched the intro and one of the gases that was used on the simulated dive to 330fsw was hotx. Thanks for the help. http://www.abysmal.com/english.html I think it's a net intro give us a better link to the exact article, i would be interested in reading it. I know what hetox is could that be what they where talking about for deep dives AquaTec October 12th, 2002, 01:15 AM Uncle Pug once bubbled... We use 30/30 for dives to 120' We subtract 15% for our EAD. We reckon oxygen the narcotic equivalent of nitrogen. We actually suspect that it is more so. At least it *feels* that way. PUG I would be interested to know more about the narcotic effects of Oxygen and how it compares to N2 Know I do not consider O2 toxicity as a narcotic effect ScubaDan October 12th, 2002, 02:24 AM No article that I know of, just the INTRO movie that used Hotx and I just wanted to know what it was. Thanks for the help. AquaTec October 12th, 2002, 02:51 AM I found this on the internet. An Introduction to HOTx Trimix is a breathing mixture consisting of oyxgen, helium and nitrogen. Traditionally, Trimix has been used as a deep diving gas as it is less narcotic at depth than air or nitrox. Usually these mixes contained an oxygen percentage less than normoxic (less than 21% oxygen). The oxygen content was kept low due to the possibility of CNS oxygen toxicity problems when breathing partial pressures of oxygen greater than 1.6 atmosopheres. The technical diving commumity has long recognized the risks associated with conducting deep dives while breathing narcotic mixes. More recently that recognition has been extended to include intermediate deep dives (100 to 170 feet seawater). To reduce the associated risks many divers are using Trimixes containing 21 percent and higher fractions of oxygen. These intermediate deep diving gases are known by a variety of names. Call it "Normoxic Trimix," "Helitrox" or "High Oxygen Trimix" (HOTx), the principle is the same. By displacing some of the nitrogen content with helium the gas is less narcotic, thus reducing risk to the diver. Technical diving courses providing training in the use of high oxygen trimix are gaining popularity. Via these programs it is now possible to climb the training ladder to the Trimix level without having to be exposed to deep air diving. Due to the special considerations involved in conducting these types of dives because of the addition of helium to the mix, divers should seek specialized training before attempting to execute HOTx dives. Currently, HOTx is used almost exclusively for stage-decompression diving. As such it is considered a technical diving gas. Recently, however, a great deal of experimentation has been being done concerning using the gas for no-stop diving. In the not too distant future HOTx may become a mainstream recreational diving gas for no-stop dives in the 100 to 130 foot range. http://www.sportdiverhq.com/hotx.htm ScubaDan October 12th, 2002, 11:10 AM Thanks AquaTec October 12th, 2002, 03:53 PM It seems like a waste of good helium to use it on NDL diving, or diving where narcosis is not a factor. Uncle Pug October 14th, 2002, 12:09 PM I missed your post to me in this thread a page back. There is controversy about the narcotic effects of oxygen. While its lipid solubility would suggest that it has greater narcotic potential than nitrogen that is not necessarily the case. Since there is no definitive word on whether it is or it isn't... We regard, for our purposes, O2 to be as narcotic as nitrogen... and subjectively it *feels* that it is so. Jarhead October 14th, 2002, 12:34 PM Uncle Pug once bubbled... Since there is no definitive word on whether it is or it isn't... We regard, for our purposes, O2 to be as narcotic as nitrogen... and subjectively it *feels* that it is so. You're happy to get in the water.;) roakey October 14th, 2002, 12:41 PM Bill Hamilton thinks that O2 should be considered in END calculations. So this means we're looking at not exceeding an END of 4 or 5 ATA (pp O2 + N2) depending if 100 or 130 feet is your pleasure. Roak Uncle Pug October 14th, 2002, 12:47 PM Jarhead once bubbled... You're happy to get in the water.;) And I have out of state scuba board visitors to take diving!!! Heath and his wife will be here this week and Metridium will be here next week. :) detroit diver October 14th, 2002, 12:59 PM Make sure you show 'em the octopus! I'm jealous.... Uncle Pug October 14th, 2002, 01:20 PM detroit diver once bubbled... I'm jealous.... ...don't you have some business out here... surely a man of your resourcefulness could come up with an excuse :D Speaking of octopus... Shane an I spotted a medium sized one at Hat Island Saturday. The visibility was also fairly good as well. We had some visitors along from Scuba Board... not diving yet... just learning how to run the boat... so we were able to cover a lot of ground. But I though about you as it would have been another good day for flying the anchor. :D AquaTec October 14th, 2002, 03:39 PM Uncle Pug once bubbled... I missed your post to me in this thread a page back. There is controversy about the narcotic effects of oxygen. While its lipid solubility would suggest that it has greater narcotic potential than nitrogen that is not necessarily the case. Since there is no definitive word on whether it is or it isn't... We regard, for our purposes, O2 to be as narcotic as nitrogen... and subjectively it *feels* that it is so. PUG - thanks for your responce It ould seem if that was actualy the case then high PO2 would have a very narcotic effect, or are you saying that the good feeling you get after a nitrox dive may not be from the reduced N2 but actualy from the high PO2. if that was true then having a high end wouldn't be a problem, however you do get just as narced with an end of say 180 feet wheather you have 9% O2 or 21% O2. just throwing out some thoughts here, and looking for more info from you. I find this theory interesting. final thought - to stay on topic, if you where using HOTx then you are not adjuting the O2 vs EANx you are realy just redusing the N2 by replacing it whith He. I am thinking of the example above of a 30/30 mix
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