F
Falling Slowly
Student
- Sep 9, 2023
- 133
EEBD Hood Setup
I have an Emergency Escape Breathing Device (EEBD ) hood with inert gas setup. My one looks like this:
Here's another pic example.
Some people lately were asking questions about the hood setup, and how to attach it to a cylinder, etc. I'm doing this thread so that I can easily link to it in future, if people ask about the setup on the inert gas megathread. Just giving my two cents.
You basically need 3 main items:
1) inert gas cylinder (nitrogen, argon, or helium)
2) a gas regulator with a flowmeter, to control the flow of gas going into the hood and to ensure you have enough minutes of gas flow to ensure ctb.
3) EEBD hood (also called Rescue hood, or Emergency Life Support Apparatus(ELSA) hood).
Gas
For the gas, you need to ensure it has a near 100% purity (seller usually states this). Then you just need to know how much compressed gas is in the cylinder, to ensure there's enough to ctb.
Calculating how many litres of gas in a cylinder
Given that it's recommended to set a gasflow of 15-25 LPM of gas to ctb (I'd go with 25lpm), and given that the PPH says that death occurs after 5-10 mins (unconsciousness after 30-60 seconds), you need to know how many litres of gas in the cylinder to ensure there's enough to ctb.
Unfortunately, gas cylinder size is usually given in different ways, depending on the region. So the way of working out how much compressed gas there is can vary. But it's usually sold as either:
1) Cubic feet of compressed gas (e.g 40 cu/ft). Just convert this to litres using an online converter.
(e.g. 40 cu/ft = ~1133 litres of compressed gas)
2) Metres cubed of compressed gas (e.g. 2m³ of compressed gas). Again, convert to litres using converter . (1m³ = 1000 litres of gas).
3) Confusingly, in some regions, e.g UK, they often give the cylinder size by how much water volume it can hold. E.g. 2 litres, or 9 litres, as opposed to the volume of compressed gas. They also usually give the pressure of the cylinder in bar. To get the approx. volume of compressed gas, just multiply the water volume by the bar pressure. ( e.g. a 9l cylinder at 137 bar pressure gives 1233 litres of compressed gas (9×137).
How long will the cylinder gas flow last?
Once you know how many litres of compressed gas you have, you can work out how long the gas flow will last for. The recommended gasflow setting to ctb( which you set on the regulator) is between 15 and 25 LPM. If you have enough gas, go with 25 LPM. To calculate how long the gas flow will last, just divide the total volume of compressed gas by the gasflow LPM ( e.g. if you have 1133 litres of compressed gas, and are going to use a regulator gasflow of 25 LPM, this will give ~ 45 mins of gasflow (1133÷25).
Gas Regulator
You need a nitrogen or argon regulator with a flowmeter, to control the gasflow from the cylinder. The flowmeter shows the flow of gas in either litres per minute (LPM), or cubic feet per hour (CFH, or SCFH (standard cubic feet per hour). If you get a flowmeter with CFH readings on the gauge, use a converter to convert to LPM.
Given that you'll be potentially using 25lpm gas flowrate, make sure the LPM readings on the regulator go above 25 LPM .
(Some people have used click-style regulators)
EEBD hood
You can get cheap EEBD hoods on Alibaba. Try and get one that has an exhalation valve on it, so that when you exhale CO2, it will be exhaled out the valve. Some exhaled CO2 going directly into the hood is fine, it will be purged out the hood by the inert gas.
These hoods are designed to keep people alive by hooking them up to an air cylinder. Some hoods are sold with the air cylinder included. Try and get a hood with just the hose attached to the hood ( i.e. without the air cylinder).
Putting your setup together
Once you have the hood, regulator and cylinder, you just need an adjustable wrench, a sharp knife/utility knife(or a hose cutter/pipe cutter if the hose is tough to cut) and hose clamps.
Firstly, you can attach the regulator to the cylinder valve using the adjustable wrench:
Secondly, regulators usually come with a hose barb, which looks like this:
Attach the hose barb to the regulator, which will then look like this:
Then, cut the connector off the end of the hood hose.
Slide the end of the hose through a hose clamp. Then attach the hose end to the regulator barb, slide up the hose clamp, and tighten the hose clamp with the screwdriver.
Here is a pic of @k1w1's hose attached to a hose barb:
If the hood hose you got is very short, you can extend the hose. Some regulators come with their own hose, like this one:
If so, you can extend the hose using a double-sided hose barb. Just cut the connectors off both the hood hose and the regulator hose (if one came with the regulator; otherwise you can just buy a separate hose yourself, one similar in diameter to the hood hose). Then attach both hose ends to the double-sided barb connector:
Here is a pic of @k1w1's extended hose:
That's the setup needed.
Avoiding falling when unconscious
If attempting this method, you should strap your torso to an armchair/reclining chair/chair using tie-down straps/luggage straps that you can get in most hardware stores, to avoid falling over when unconscious, and potentially knocking over your cylinder/ regulator.
Other things to maybe take into account
Gas Purity
Some people test the purity of the inert gas by using an oximeter ( to be sure it's close to 100% nitrogen). You can either get one to put inside the hood to test the oxygen levels in it when you turn on the gasflow into the hood (some people have even used a head mannequin with the hood on it to test it.) You can also test your bodies oxygen level by hooking up your finger to an oxymeter.
Most people probably take seller of the gas cylinder at their word, if it states that the gas is 100% pure, or almost 100%.
Potential Leaks
Also, some people also test for leaks in the connections of regulator-to-cylinder, or hose to regulator. You can do this by rubbing soapy water on the connections; if there's gas bubbles forming, then it shows gas is leaking at the connection, and the connections need tightening.
Potential Cost of the Setup
My 9 litre cylinder cost €200 (euros). I had to collect it from the seller. Some places do deliveries, some only do deliveries to trade addresses, some do collection only.
My hood, a branded one, bought on a famous auction website, cost €200 (including postage). Some people got cheap ones on Alibaba for ~€20.
My gas regulator cost €110 (incl. postage). You may get cheaper ones online.
Summary
That's basically it. Instead of using a hood, you can obviously use an exit bag connected to the regulator hose barb using a tube (use the search bar for looking up the Exit Bag).
This hood inert gas method has worked for people .When done properly, it is painless and peaceful. (Indeed, in the past many people have ctb'd using only a gas cylinder(usually helium) and a plastic bag connected to the gas via a tube (no regulator used). In the past many people often used party balloon helium when it was 100% helium; now it is harder to get 100% helium. 100% Nitrogen and argon seem easier to source.
However, I would advise using a regulator, if you choose this method).
@Vizzy also has a longer, more extensive hood setup thread, here.
Some examples of EEBD hoods in inert gas setups here.
Obviously, I'm not advising/ encouraging anyone to ctb via this method. Seek whatever help you can, etc., etc.
I have an Emergency Escape Breathing Device (EEBD ) hood with inert gas setup. My one looks like this:
Here's another pic example.
Some people lately were asking questions about the hood setup, and how to attach it to a cylinder, etc. I'm doing this thread so that I can easily link to it in future, if people ask about the setup on the inert gas megathread. Just giving my two cents.
You basically need 3 main items:
1) inert gas cylinder (nitrogen, argon, or helium)
2) a gas regulator with a flowmeter, to control the flow of gas going into the hood and to ensure you have enough minutes of gas flow to ensure ctb.
3) EEBD hood (also called Rescue hood, or Emergency Life Support Apparatus(ELSA) hood).
Gas
For the gas, you need to ensure it has a near 100% purity (seller usually states this). Then you just need to know how much compressed gas is in the cylinder, to ensure there's enough to ctb.
Calculating how many litres of gas in a cylinder
Given that it's recommended to set a gasflow of 15-25 LPM of gas to ctb (I'd go with 25lpm), and given that the PPH says that death occurs after 5-10 mins (unconsciousness after 30-60 seconds), you need to know how many litres of gas in the cylinder to ensure there's enough to ctb.
Unfortunately, gas cylinder size is usually given in different ways, depending on the region. So the way of working out how much compressed gas there is can vary. But it's usually sold as either:
1) Cubic feet of compressed gas (e.g 40 cu/ft). Just convert this to litres using an online converter.
(e.g. 40 cu/ft = ~1133 litres of compressed gas)
2) Metres cubed of compressed gas (e.g. 2m³ of compressed gas). Again, convert to litres using converter . (1m³ = 1000 litres of gas).
3) Confusingly, in some regions, e.g UK, they often give the cylinder size by how much water volume it can hold. E.g. 2 litres, or 9 litres, as opposed to the volume of compressed gas. They also usually give the pressure of the cylinder in bar. To get the approx. volume of compressed gas, just multiply the water volume by the bar pressure. ( e.g. a 9l cylinder at 137 bar pressure gives 1233 litres of compressed gas (9×137).
How long will the cylinder gas flow last?
Once you know how many litres of compressed gas you have, you can work out how long the gas flow will last for. The recommended gasflow setting to ctb( which you set on the regulator) is between 15 and 25 LPM. If you have enough gas, go with 25 LPM. To calculate how long the gas flow will last, just divide the total volume of compressed gas by the gasflow LPM ( e.g. if you have 1133 litres of compressed gas, and are going to use a regulator gasflow of 25 LPM, this will give ~ 45 mins of gasflow (1133÷25).
Gas Regulator
You need a nitrogen or argon regulator with a flowmeter, to control the gasflow from the cylinder. The flowmeter shows the flow of gas in either litres per minute (LPM), or cubic feet per hour (CFH, or SCFH (standard cubic feet per hour). If you get a flowmeter with CFH readings on the gauge, use a converter to convert to LPM.
Given that you'll be potentially using 25lpm gas flowrate, make sure the LPM readings on the regulator go above 25 LPM .
(Some people have used click-style regulators)
EEBD hood
You can get cheap EEBD hoods on Alibaba. Try and get one that has an exhalation valve on it, so that when you exhale CO2, it will be exhaled out the valve. Some exhaled CO2 going directly into the hood is fine, it will be purged out the hood by the inert gas.
These hoods are designed to keep people alive by hooking them up to an air cylinder. Some hoods are sold with the air cylinder included. Try and get a hood with just the hose attached to the hood ( i.e. without the air cylinder).
Putting your setup together
Once you have the hood, regulator and cylinder, you just need an adjustable wrench, a sharp knife/utility knife(or a hose cutter/pipe cutter if the hose is tough to cut) and hose clamps.
Firstly, you can attach the regulator to the cylinder valve using the adjustable wrench:
Secondly, regulators usually come with a hose barb, which looks like this:
Attach the hose barb to the regulator, which will then look like this:
Then, cut the connector off the end of the hood hose.
Slide the end of the hose through a hose clamp. Then attach the hose end to the regulator barb, slide up the hose clamp, and tighten the hose clamp with the screwdriver.
Here is a pic of @k1w1's hose attached to a hose barb:
If the hood hose you got is very short, you can extend the hose. Some regulators come with their own hose, like this one:
If so, you can extend the hose using a double-sided hose barb. Just cut the connectors off both the hood hose and the regulator hose (if one came with the regulator; otherwise you can just buy a separate hose yourself, one similar in diameter to the hood hose). Then attach both hose ends to the double-sided barb connector:
Here is a pic of @k1w1's extended hose:
That's the setup needed.
Avoiding falling when unconscious
If attempting this method, you should strap your torso to an armchair/reclining chair/chair using tie-down straps/luggage straps that you can get in most hardware stores, to avoid falling over when unconscious, and potentially knocking over your cylinder/ regulator.
Other things to maybe take into account
Gas Purity
Some people test the purity of the inert gas by using an oximeter ( to be sure it's close to 100% nitrogen). You can either get one to put inside the hood to test the oxygen levels in it when you turn on the gasflow into the hood (some people have even used a head mannequin with the hood on it to test it.) You can also test your bodies oxygen level by hooking up your finger to an oxymeter.
Most people probably take seller of the gas cylinder at their word, if it states that the gas is 100% pure, or almost 100%.
Potential Leaks
Also, some people also test for leaks in the connections of regulator-to-cylinder, or hose to regulator. You can do this by rubbing soapy water on the connections; if there's gas bubbles forming, then it shows gas is leaking at the connection, and the connections need tightening.
Potential Cost of the Setup
My 9 litre cylinder cost €200 (euros). I had to collect it from the seller. Some places do deliveries, some only do deliveries to trade addresses, some do collection only.
My hood, a branded one, bought on a famous auction website, cost €200 (including postage). Some people got cheap ones on Alibaba for ~€20.
My gas regulator cost €110 (incl. postage). You may get cheaper ones online.
Summary
That's basically it. Instead of using a hood, you can obviously use an exit bag connected to the regulator hose barb using a tube (use the search bar for looking up the Exit Bag).
This hood inert gas method has worked for people .When done properly, it is painless and peaceful. (Indeed, in the past many people have ctb'd using only a gas cylinder(usually helium) and a plastic bag connected to the gas via a tube (no regulator used). In the past many people often used party balloon helium when it was 100% helium; now it is harder to get 100% helium. 100% Nitrogen and argon seem easier to source.
However, I would advise using a regulator, if you choose this method).
@Vizzy also has a longer, more extensive hood setup thread, here.
Some examples of EEBD hoods in inert gas setups here.
Obviously, I'm not advising/ encouraging anyone to ctb via this method. Seek whatever help you can, etc., etc.
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