Nest CO alarm

SuperTech

Recently I had to sit through a Google Nest training class. One of the things that was discussed was a WiFi Fire/CO alarm that when paired with everyone's favorite Nest thermostat has the ability to shut off your furnace or boiler if it detects CO.

But....only if it detects 70-110 PPM for 60 -240 minutes! How is this considered acceptable? The Nest rep tried claiming that those levels for that amount of time were not long enough to suffer any adverse effects. 

STEVEusaPA

Well ask the rep if he wants to put his money where his mouth is.
Set the burner to fire dirty at 70+ ppm CO, remove the flue pipe. Tell him to head down the basement, and you’ll come get him, wearing your respiratory, in an hour.
Think he’ll go for it? Lol
In reality, won’t kill a healthy person, but I wouldn’t want to risk an elderly person or immunocompromised to that exposure.

HVACNUT

With oil, most want <50 ppm in the flue. With gas, most want <60 ppm. Some want <100 PPM on high fire. Why would more be acceptable in the living space?
What I would like is for the smoke alarm to hold off for 10 minutes so it realizes I'm just burning the damn pancakes again.

STEAM DOCTOR

Imminent death is not the only concern. Long term, low level exposure , ain't particularly healthy. 

SuperTech

I remember seeing a chart on here once. If I remember correctly @pecmsg or @captainco posted it. It shows the effects of CO on someone at certain levels over a span of time, I'd like to see that again. 

I could be wrong but I thought the threshold was lower than that for your average UL certified CO detector that is available in the hardware stores.

Either way I wish these new products would strive to achieve a higher standard.  I guess it would be useful as a secondary alarm used to shutdown equipment along with a good low level CO detector. 

pecmsg

SuperTech said:

Recently I had to sit through a Google Nest training class. One of the things that was discussed was a WiFi Fire/CO alarm that when paired with everyone's favorite Nest thermostat has the ability to shut off your furnace or boiler if it detects CO.

But....only if it detects 70-110 PPM for 60 -240 minutes! How is this considered acceptable? The Nest rep tried claiming that those levels for that amount of time were not long enough to suffer any adverse effects. 

70 PPM or more for up to 3 hours is the UL-2034 listed requirements. Why that high? Something about too many alarms!

Now no one mentions effects of long-term exposure to above 70PPM for 3 hours and I'd rather not find out.

pecmsg

Bob Harper

CO alarms listed to UL 2034 and 2075 are DEATH alarms only. They do NOT provide protection against CO poisoning. Think about that. The alert levels, based upon exposure concentration, are calculated such that the algorithms trigger alert at what would theoretically equate to the carboxyhemoglobin (COHb) level of a smoker deemed to have CO poisoning- 10% COHb. The partial pressures of the concentration of gas are the primary determinant in the uptake of CO. There's a lot more physiology but for our purposes, its what we're most concerned with. So, the UL standard is perfectly happy with you huffing non-lethal levels of CO for protracted periods. Yet, people are mislead to believe they are 'protected'. You need an unlisted low level CO monitor. UL listed alarms slaved to heating equipment are a joke. They cannot respond fast enough. As a retired paramedic, who has personally transported many CO cases, many of which required hyperbaric oxygen therapy, and who has personally been poisoned several times before I began carrying a personal alarm, I'm well aware of the hazards. Note that certain people are at greater risk, including infants, elderly and certain medical conditions.
If they want a fast responding low level alarm, install a 3M Macurco and adjust the alert level & response times along with actions.
HTH

SuperTech

I can't say it enough.  This forum is the best. I knew that if I created this post I would get information I was looking for.  @Bob Harper thank you for sharing your experiences and validating my concerns.  As a tech who services a lot of oil and gas equipment protecting my customers from the potential dangers involved with fuel burning appliances is the most important aspect of my job.