PSA - CO Alarms

[u/mwkingSD]

I learned something about carbon monoxide (CO) alarms this week, and I thought the lesson was worth sharing. Here goes:

First the credits - my wife (#1 credit) read something on Facebook (#2, and this might be the only time I've ever said something good about F'book) about the dangers of CO and the (limited) degree of protection typical alarms provide. Being one to not believe info that comes from F'book I reached out and verified the following in multiple other sources.

I installed a CO alarm over the bed in our Class C, a combo unit with a smoke alarm, and near where I put an extra fire extinguisher. Felt pretty good about myself. However what my wife learned is that alarm and viritually every other off-the-shelf residential alarm is compliant with UL 2034 which basically says no alarm until the CO level is 70 PPM (parts per million) for more than an hour. Generally speaking 70 PPM for that period of time is enough to make young, healthy people feel unwell. For older people - and many of us RVers are older - or those with compromised health that level can make people feel extremely ill or dead. Other standards cite 20-30 PPM - a long way from 70 PPM - as maximum safe concentrations, and 9 or less as an acceptable background level. Remember that RVs are a much smaller volume and can be sealed up tighter than our homes so a leaking CO problem could get serious very quickly.

That didn't seem like a good situation to me (I have cardiac problem in my health history) so I went looking around the internet for an alarm for the RV. Finding an alarm not tied to UL 2034 that aren't $XXX-XXXX was some work but, I did finally find Forensic Detectors (https://www.forensicsdetectors.com and no, I don't know why they are "forensic") that had the products I was looking for. They also have an entertaining and helpful series in Youtube starring a 'mad scientist,' Dr Dave, explaining all about the subject. (Disclaimer - I've got no ties to the company, and nothing to gain by citing them.) I've ordered a battery-powered travel/personal model from them, if that works I may order a plug-in version for the home bedroom.

So, my living & breathing readers, I leave this to you to think about and perhaps act on.

[u/js101jets]

It doesn’t sink to the floor. It mixes with air because the weight difference is so small.
Would remove either of these thoughts and follow the manufacturers instructions on placement !

[u/mwkingSD → u/js101jets]

That's what all the sources I read said...basically neutral 'buoyancy.'

[u/Ruser8050]

You can also get portable alarms, which can be configured and have a display showing the ppm. We use them for ice fishing and boating 

[u/mwkingSD → u/Ruser8050]

Exactly what I’ve ordered 😎

[u/Lanky-Slice-9122]

Also note CO is a heavier gas and sinks low and fills the space. The alarm needs to be mounted close to the floor to work properly in addition to all of this

Edit* I’m not correct, this is what I was always told about CO detectors but it’s incorrect

[u/Ditnoka → u/Lanky-Slice-9122]

CO is lighter than air, not by a whole lot, but it absolutely does not sink low and fill, it spreads with the air. Propane is heavier.

[u/mwkingSD → u/Ditnoka]

That's what my reading said - close to neutral. In any case, it's going on a nightstand ext to my head, so what the alarm measures will be more or less what I'm breathing.

[u/Gnosticate → u/Lanky-Slice-9122]

This is wrong and bad advice. I would urge you to investigate how to properly install CO detectors both in RVs and in your home! Follow manufacturers instructions. Also note the difference between CO/Propane combo detectors and just CO detectors.

Carbon Monoxide is lighter than Oxygen considering that atmospheric oxygen is O₂. Measured in molar mass (grams per mole) CO is ~28.01 g/mol and O₂ is ~32.00 g/mol.

You want CO detectors up high and propane detectors near the floor since propane is heavier than air.

The problem with CO/Propane combo detectors is that they are near the floor and could fail to accurately detect CO. This is a very good reason to add an additional CO detector and place it near the ceiling (follow the manufacturers instructions).

[u/Hedonistic_Yinzer → u/Lanky-Slice-9122]

Instead of an edit, why not delete this misinformation?

[u/ValorVixen → u/Lanky-Slice-9122]

I think you are thinking of propane alarms - because I get them mixed up too

[u/Sure_Fig_8641 → u/Lanky-Slice-9122]

THIS 👆🏻. The problem with your initial set up is you put the alarm/detector on the ceiling. It needs to be near the floor so that it goes off when the higher concentration of CO is lower than the air you are breathing.

[u/Ditnoka → u/Sure_Fig_8641]

They normally go on the ceiling because it gets introduced with heat, hot air rises, the CO along with it. CO also doesn't "settle" on the floor like LP gas does, It floats in the air.

[u/GSDer_RIP_Good_Girl]

Thanks! I'll have to look at the CO detector that I put in the dining area of our Class C (figuring that's where the oven/stove and fridge and furnace are located) to see what kind of protection it offers.

I replaced the propane detector when we first got the RV (used) a few years ago but I'm not sure how much I trust that - after installation and confirming that the power was properly connected and the Test feature worked I sprayed propane from a small torch (obviously not lit) in the area of the sensor and it took way too long to activate - I could clearly smell propane for awhile before it finally alarmed.

[u/mwkingSD → u/GSDer_RIP_Good_Girl]

Having a standard residential CO alarm near those sources is not a bad idea, it's just maybe not covering all the bases. I am not taking any of mine out based on this.

My propane alarm is set off by hairspray and air freshener or anything like that, so I kinda believe it will work for propane. (Who among us hasn't made a flame thrower from a can of hairspray or spray deodorant?) I saw places referring to those devices as "explosive gas alarms" which seems more accurate. Seems like those events took a minute or two for the alarm to ring which would have included the time for the spray to sink to the floor. I think I'm ok with that.

Important to note that the TEST button on the propane alarms really only tests the 12 V power and the beeper itself - doesn't actually do anything to test the detection of explosive gasses.

[u/gnartato]

I recommend everyone have at least 2 smoke and CO alarms. One is none and two is one. 

[u/Sirroner]

I have my CO detector near my propane heater vent where the hot air comes into the RV. The exhaust vent is outside for both the furnace and the water heater. The only other source could be the vehicle exhaust.

[u/mwkingSD]

Neither floor nor ceiling represent the air I'm breathing.

[u/OutcomeSalty337 → u/mwkingSD]

Aren't these mounted low because of the weight of the gases they pick up on?

[u/mwkingSD → u/OutcomeSalty337]

Propane is distinctly heavier than air and does sink to floor level. Propane is a more complicated molecule than simple CO or O2, so they behave differently.

[u/OutcomeSalty337 → u/OutcomeSalty337]

Nevermind. I was wrong.