Understanding Low-Level CO Monitors | Ask This Old House

[@sherryjablonski1029]

Yes, low level detectors are important to have as well! My regular over the counter, round alarm did not detect or sound when I was getting sick for several months. I had no idea the ones you buy for every day use don't sound until a certain level is reached. The one I had didn't sound all winter and it wasn't until my symptoms were so terrible that I couldn't stand it any more and started doing my own environmental investigations by having service people come and check for mold and assess my HVAC system. The service tech found a leak and crack in my HVAC with his commercial monitor. Very dissapointing and confused on which is best to have on an everyday consumer basis since mine didn't alert me. This video is helpful.

[@dac7046]

30 years ago this type of CO detector bought on a whim led to discovery of potentially lethal furnace problem in our home with 2 young children. What TOH failed to say is that there are good yet inexpensive detectors (Nighthawk is the one we had) not just the $100+ models they are pushing. Also, the CO detection chemistry gets depleted so these things last 10 years or less.

[@rosstret]

Thank you for sharing!

[@chinabrian9884]

Grateful to have found this. Recently becoming concerned about low levels of CO impacting fatigue and headaches from our gas oven/stove. Sometimes when using it I smell the gas, but my regular CO alarms never go off and I have been unsure of a reliable device for detecting lower levels.

[@christiefleming5583]

This is so exciting!! You are truly so kind to share your knowledge. Looking forward to your new journey. Thank you again 😊

[@qcsupport2594]

Also: if your low-level monitor is showing non-zero, your furnace heat exchanger might be starting to rust out and you can catch it way before it finally trips the code-required CO detectors, maybe even years earlier, during which you would otherwise be breathing CO. (Any appliance that burns gas - even a water heater - could cause this if there's an issue with the combustion itself or the ventilation of the combusted gases. )

[@majortom2224]

I have a CO detector on every level of my house. 3 of them with digital readouts. All three have a peak display as well. I had a 2 stage Hi Eff furnace that was leaking CO into the hot air supply only when it was in the second stage or high heat The furnace was inspected, tested, serviced 3 months ago and passed with flying colours. The tech tested for CO in first stage heating and second stage even tested the CO output on the exterior exhaust pipe. AND there was the downfall! He didn't recognize or know what the reading of CO was telling him in second stage heat. IT was a low reading at the exhaust pipe of 11 ppm which was actually two low, It should have been closer t0 20 ppm or higher. So for months I was suffering symptoms of low level CO poising and NONE of the CO detectors triggered because the CO was below the trigger points of level and time. Got 2 tech in from the company and the second tech knew instantly after running the furnace what the problem was..a crack in the heat exchanger that opened just a fraction as the heat exchanger got much hotter in the second stage of heating. Note: this was his his diagnosis without physically inspecting the exchanger itself. Low levels CO poisoning is a real threat but until I stated researching it I was totally dependent on my CO detector that never went into an alarm state. I had symptoms of rapid heart rate, skipped heart beats, the worst BRAIN FOG, just on the edge of a headache and nausea and a real need to keep opening windows without knowing why.

[@sandracohen8481]

I have two parrots in my home and need a low-level detector Defender vs co experts vs nci6000 Are any others you recommend Thank you

[@BillSpohn]

I’ve been working as an expert witness on CO cases since 2006. My company (TruTechTools$) sells CO Experts and Defender alarms. The NCI ones are available only through NCI contractors. All three brands are fine products in my opinion. They have a few feature differences, but basic functionality is similar.

[@robertbamford8266]

Excellent information. Even UL says its acceptable levels may be too high for elderly, immuno-compromised. Will have to look into sensitivity of the “approved” devices required by code (California) in my home.

[@timrowlett5451]

All about PPM and TWA. Parts per million and time weighted average. Good info.

[@BillSpohn]

As the commenter and video noted, it’s about concentration and time of exposure since CO is a cumulative poison.

[@ncooty]

@0:17: Since when is wood a fossil fuel?

[@sowardsconstruction]

Can ya tell us more about radon meditation units

[@BillSpohn]

There are new radon measuring devices, AirThings brand, that my company sells (TruTechTools). They will alert you as radon levels that change due to various factors. Radon mitigation systems (ducting and fans) need to be installed by qualified professionals which can be easily found on line. I assessed high radon levels in my own new home and had to install a radon mitigation system to get below recommend target concentrations.

[@jasonmartin6949]

Wonder if there's a cheaper, or free, way to test the levels without having to purchase a low-level CO monitor? We have only electrical appliances and never have used our gas fireplace (propane). However, often have headaches and now wondering if CO might be cause.

[@StuffTested]

It's all about how worth it is to you. Is your health worth the $50-$150 for a low level CO monitor? You could shut off the main gas supply line. Propane does usually have a smell however. A free, but unreliable option would be to have a friend come over and ask them if they smell anything, but obviously that's not good enough.

[@rustyshackle917]

Could be mold, particulate matter, low oxygen levels, VOCs... you should have a good ventilation and filter system doing X number of air changes per hour (depending on house size/number of people).

[@j12997967]

@@rustyshackle917 Yep, or even high levels of carbon DIOXIDE, which can be a concern in "tighter" houses where leaks are minimal, reducing air exchanges, normally a desired effect, but Richard Tretheway often discusses the membrane-based heat exchangers that are important for bringing fresh air into tight houses.

[@BillSpohn]

Sadly CO cannot be detected without a measuring sensor and these engineered devices have a price, as said $100-$200

[@vmobile890]

@@StuffTested After seeing the high end models and Fire department wearable i’m going to spend a few hundred for family gifts .

[@brianreese9318]

Every thing safety wise has gone up in price so bad are safety should be affordable for all who need em smoke detectors have gotten out of hand in prices

[@spacetoast7783]

A smoke detector is like $10 and lasts 10 years. That's affordable to 99.9% of homeowners.

[@volvo09]

What? No they aren't. A dinner out costs more than a few smoke detectors and a CO detector, and those last years, not hours.

[@txshah78]

You are correct. Smoke detectors are overpriced. People in low income home can’t afford to buy or replace these.

[@spacetoast7783]

@@txshah78 You're talking about people so poor they literally have no home to protect.

[@TrumpAmerica-2024]

stop voting democrat!

[@Mike_Greentea]

Does the alarm go off if someone farts? Asking for a friend.

[@vmobile890]

That’s methane and a few presidents said it’s climate change so best not fart . It should show a difference in climate change in 10,000 years or more .

[@eklectiktoni]

Flatulence is mostly methane, CO2, and hydrogen sulfide gas, not CO which is why it smells bad.

[@DenaliDad]

So I watched this and came away with the, “And the point is…?” question. Is TOH now saying that we should remove every bit of everything bad from everything we take into our system? One part per million of some bad stuff in water should, what…? Make us not drink? What is the point?

[@RositaQuinonez-i3g]

🤙🍍🏝 0:37

[@JimE6243]

CO alarms "...mounted on the ceiling." ?????

[@TrumpAmerica-2024]

😂😂😂

[@RatKindler]

According to First Alert's web site CO is slightly lighter than air but diffuses throughout a room evenly, so their CO detectors can be mounted on the ceiling. Kidde's web site doesn't specify any particular location in the room as long as it's not in a "dead space" area.

[@Rymac91]

A lot of CO detectors are built into combination CO smoke detectors so they're typically on the ceiling. CO distributes itself evenly in a room with a slight bias away from the floor, so placement of CO detectors is a lot easier than smoke detectors.

[@knowledgeispower6192]

CO is heavier than Oxygen. I'd mount low

[@RatKindler]

@@knowledgeispower6192 CO could be heavier than oxygen but it's lighter than air.

[@bolu3846]

You can not go down to "zero". This show has some problem unforunately. Kevin actually questioned Ross about it :)

[@scotttovey]

"You can not go down to "zero"." Sure you can. Lock yourself in a sealed oxygenated room. Put on an oxygen mask that exhausts your exhaled breath our of the room. There are obvious problems with this like the need to eat and use the facilities. But isn't that what the environmentalists are shooting for?

[@micsonicman]

I never heard him say that??? What time stamp does he imply zero?

[@rosstret]

www.epa.gov/indoor-air-quality-iaq/what-average-level-carbon-monoxide-homes

[@bolu3846]

Ross said that "zero was where I am try ...". go watch again.

[@rosstret]

Trying to get down to 0. Technically should have said 0.5 ppm. 😂

[@bolu3846]

How much of carbon monoxide is in the air? Carbon monoxide is the most abundant, by mass, pollutant gas. Atmospheric carbon monoxide levels in typical urban areas are around 10 ppm (parts per million), about 100 times higher than in Earth's atmosphere overall. In areas with heavy traffic, CO levels can rise to as high as 50 ppm.

[@rosstret]

Incorrect. Indoor levels are typically in the ~0.5 ppm range. Outdoors depends on where you live but is ~0.5 in Massachusetts. Here is more info- www.epa.gov/indoor-air-quality-iaq/what-average-level-carbon-monoxide-homes

[@rosstret]

Here is the outdoor CO levels in the New England states from 2022…www.epa.gov/system/files/documents/2023-06/CO_2022.pdf

[@TrumpAmerica-2024]

silent but deadly

[@racpa5]

Hi

[@johnlebzelter4208]

@racpa5 leave troll!

[@racpa5]

@@johnlebzelter4208 Sorry, not trying to be a troll…just surprised to be first commenter.

[@romuloromero2268]

Poor information. More like scare tactics. What level are we targeting? Are they recommending zero ppm??

[@HermanVonPetri]

They already said it would be different for different people. Some people have lung dysfunction like emphysema where they don't take in enough oxygen and can't tolerate as much CO as healthier people. Some people are home cooks that may have a gas stove running most of the day and have a longer period of exposure than others. Some people may have a malfunctioning heating system or a leak where the levels spike for short periods of time but not long enough to set off alarms.

[@MikeHoughtonasUnit8720]

can't be zro though. we breathe out co.

[@CJRoe]

No way you would ever exhale enough to set a co monitor above zero under normal circumstances. Shoving in your mouth and letting about a huge breath might tik it up but it will fall as fast.

[@TrumpAmerica-2024]

we breathe out CO² not CO

[@res00xua]

carbon monoxide makes a strong bond with hemoglobin and is cumulative. Our Hvac contractor measured the levels from our gas furnace and replaced the burner to reduce the output of CO.

[@rosstret]

CO (carbon monoxide) is not the same as CO2 (carbon dioxide)

[@Confoil]

@@TrumpAmerica-2024 Carbon dioxide is not CO² , it's CO₂ . As for breathing out CO (carbon monoxide), the OP is correct in that we do breath out CO - we do it every time we breath in CO. That being said, if the OP was trying to say that we produce CO through normal, human respiration then he's mistaken and probably confusing CO₂ (carbon dioxide) with CO.