So I just bought a car in like 5 years. But my question is this how often should I keep the heat recirculating button ?
Posted by XxLuhDomoxx@reddit | askcarguys | View on Reddit | 30 comments
I normally turn off my heat/air when I'm to cold or to hot (bi polar ass mid western state ) so the weather is all over the place at times. So normally I have it on then turn my heat off after I get to hot so like after 20ish minutes or so Same with my air. I'm new to this and I don't want to kill myself due to CO2 poisoning ya know. I also feel like when I'm using the button it feel like I can feel it more and more but help
LindsayOG@reddit
Using your fresh air button will not kill you with CO2. Bringing in fresh air is generally the default and preferred.
Ancient_Narwhal_9524@reddit
But CO2 is what plants crave
BEEZ128@reddit
Are we plants?
Ancient_Narwhal_9524@reddit
I think the OP is Mr Potato Head
Albert14Pounds@reddit
Brawndo now with MORE CO2
Crazy_Judgment_4186@reddit
You're overthinking it a bit, recirculate just reuses cabin air, it won't cause CO2 poisoning in a normal car. Use it with A/C when it's really hot, but turn it off occasionally so fresh air comes in and windows don't fog.
Triangullum@reddit
Do you honestly think that a car manufacturer would include a button that causes the inside of the cabin to fill with co2? Like think about it for literally one second.
XxLuhDomoxx@reddit (OP)
Well I fell asleep in the car with it on. Was parked and pulled over so I started freeing out
ktappe@reddit
It is coincidence that you fell asleep. Unless your car has a serious malfunction with the exhaust system that is letting CO2 into the car, you can safely use any/all of the climate controls without fear of CO2. Now, if your car does have such a malfunction, you would get a very strong smell of exhaust in the car. Are you? If you are, take it to a mechanic immediately.
XxLuhDomoxx@reddit (OP)
Sometimes when I turn on my heat I get this strong smell but that’s normal I think then I don’t smell it anymore after that
BEEZ128@reddit
Inhaling a bit of carbon monoxide won’t kill you. What sort of car is it?
XxLuhDomoxx@reddit (OP)
Nissan Sentra 24
EGGWURST@reddit
There is an incredible amount of misinformation about how this button works, what it does, and its problematic usage. And for some reason this misinformation is so rampant on this sub that a lot of people will share the complete 180 of the truth with zero evidence to support their claims.
With that being said, if your car does not have an auto-turn off for the button, if you leave it on too long it will deplete the oxygen supply. The effect is generally not powerful enough to kill you outright, but it can cause drowsiness and even loss of consciousness which can be a really bad thing if you're behind the wheel. I'm sure this comment will get downvoted and I will get swarms of people saying that I'm fear mongering or that my claims are BS, but I haver evidence for these claims. If anyone has evidence that this is NOT the case ("car manufacturers wouldn't do that" doesn't count), then I would be happy to review it and possibly retract my statements.
Sources:
https://pubmed.ncbi.nlm.nih.gov/28873666/ (TL;DR, RC button has been demonstrated to create an oxygen deficit when used for prolonged periods of time)
https://www.sae.org/news/2017/04/co2-buildup-in-vehicle-cabins-becoming-a-safety-issue (TL;DR, RC button has been linked to several collision deaths)
https://pmc.ncbi.nlm.nih.gov/articles/PMC5544137/ (TL;DR, RC button has been showed to lead to reduced cognitive function and drowsiness)
lastwraith@reddit
Did you actually read these articles?
Because the first one says that recirc doesn't cause the in-car concentration to cross a level that is even near detriment unless there are 2 people in the car and nearly 30 mins have elapsed. OP is one person.
The article also states that recirc can be beneficial by helping to exclude outside pollutants and the reason for "oxygen depletion" is CO2 buildup from a gaggle of breathing passengers, not some CO accumulation that's going to knock you out without you knowing it.
These TL:DRs are misleading.
EGGWURST@reddit
The problem is when people leave it on for longer than 30 mins, more like for an hour or two. Especially if there are multiple people in the car. I'm not claiming that OP got tired because of this recirc button, in fact I think that is unlikely unless he had it on for hours on end. However, there is sufficient evidence to claim that the RC button CAN be dangerous if not used properly
Albert14Pounds@reddit
Recirculating does objectively increase CO2 levels. Your car is also far from air tight. But people are not routinely suffocating by not understanding how a button in their car works.
Currently average atmospheric CO2 levels are ~400ppm. Around 700ppm people notice that the air feels stale or polluted. The desire for fresh air kicks in. Around 1000ppm+ you start to feel sleepy and cognition starts to degrade up to 2500ppm = "major cognitive dysfunction".
OSHA’s general limit for carbon dioxide in the workplace is 5,000 ppm for 8-hours and 40,000 ppm is considered “immediately dangerous to life or health”.
Studies have shown that levels can't easily reach 6000ppm+ with multiple occupants. So it's good to be generally aware of these effects of you're driving tired/late/fully-packed and avoid the increased risk from cognitive effects. But it's barely worth thinking about day to day driving solo and/or very far.
And if you have a reasonably modern car it likely has some sort of passive or active fresh air mixing in recirculating mode, or it just times out automatically.
BEEZ128@reddit
always set it so it takes in air from outside, unless you’re in traffic and you’re around a lot or carbon monoxide. Goes for if you’re using the AC or not.
Recirculating the stale air in the cabin will make you feel almost as drowsy as inhaling lots of carbon monoxide.
ForeskinForeman@reddit
Why has this question been asked so many times in the last few days? Beyond strange.
XxLuhDomoxx@reddit (OP)
I’m only asking bc I fell asleep in my car and I was wondering is that normal
lastwraith@reddit
When you're tired..... Yes.
BEEZ128@reddit
Just like water is wet
Ancient_Narwhal_9524@reddit
You can barely write a coherent sentence, so I think carbon monoxide poisoning is the least of your worries.
lastwraith@reddit
Or it's already too late.
goldcoast2011985@reddit
I would think that would be a reason to be even more concerned…
Healthy-Theme8261@reddit
No kidding
XxLuhDomoxx@reddit (OP)
Don’t have to be a asshole it’s just a question on a subreddit
Munster19@reddit
20 minutes should be no problem, just throw it on fresh air or crack a window every 30 minutes or so.
goldcoast2011985@reddit
I think it’s been documented that recirculate can raise the CO2 (carbon dioxide) level to a point that can contribute to sleepiness.
As long as your exhaust is clear and car in good repair, you shouldn’t get CO (carbon monoxide)
Don’t run your car with a tailpipe in the snow.
https://www.fox13news.com/news/college-student-found-snow-covered-car-dies-carbon-monoxide-poisoning-during-rhode-island-blizzard
XxLuhDomoxx@reddit (OP)
Thank you for giving me a valid answer
XxLuhDomoxx@reddit (OP)
I’m only asking bc I fell asleep in my car and I was wondering is that normal