CO Poisoning Question

[Duke Dive Medicine]

When I got my first CO monitor, I put it low in the lower level of the house, not too far from the furnace.

When the furnace was replaced 4 years ago, the techs came up and replaced the thermostat and installed a new CO monitor. The tech put it up on the wall at the same level as the thermostat. I questioned the placement and he informed me that I was wrong. Please advise me.

They generally advise to put them closer to the ceiling, but not too close so as to be placed in the area of stale air in the corners. There are directions in the packages when you buy them. I have six of them in my house: garage, two redundant detectors downstairs, two redundant upstairs at one end of the hall and one at the other end of the hall.

Best regards,
DDM

 

[Akimbo]

They generally advise to put them closer to the ceiling, but not too close so as to be placed in the area of stale air in the corners.

Another Design Factor:
A friend is a certified fire sprinkler engineer and had me install hardwired CO alarms on the ceiling to monitor 2 high-efficiency wood burning fireplace/stoves and the kitchen. This is because the CO would be carried up by the heat that generates it.

There is no combustible gas inside the house. A propane-fired boiler is in a masonry outbuilding with a generator. Hot water circulates ~10M/30' underground to the hydronic heating controls in the house. The kitchen and laundry are all-electric -- the cooktop is induction so heat is controlled as well as gas.

 

[Zef]

The directions that came with the one I bought the other day state to mount it at sleeping height in the bedroom and at sitting height in places like a living room or passageway. There was a sticker on the mounting bracket and a note in the directions that specifically stated to not mount it on the ceiling.

-Z

 

[Akimbo]

The directions that came with the one I bought the other day state to mount it at sleeping height in the bedroom and at sitting height in places like a living room or passageway.

That is best unless you have a fireplace in sleeping quarters. In practice, plug-in alarms need a power receptacle and there aren't too many near the ceiling. Hard-wired alarms for new construction or major remodels can be placed in optimum locations for the space.

 

[DandyDon]

wood burning fireplace

A major CO threat!

hardwired CO alarms

How long have you had those? I think people tend to ignore maintaining those as the backup batteries do need to be replaced and most are good for 7 to 10 years before they need to be replaced. I guess that they all have low-battery and end-of-life warnings. A local AC & Heating technician once told me that he gets a lot of business from homeowners who don't know what the low & end beeps mean.

 

[Storker]

Re placement of a CO detector: CO is marginally lighter than air, so in a stagnant airspace it would rise to the top. However, since the density difference is small air circulation would easily disturb that, so airflows and possible stagnant areas would be a lot more important for the placement of the detector. Me, I'd have that in mind and locate the detector as high as practically possible taking airflow and convection into consideration. Unlike where I'd put a propane detector, because propane is significantly heavier than air.

Tl,dr: it all depends, and hard rules have no value.

 

[Storker]

wood burning fireplace

A major CO threat!

Only if your fireplace has an inadequate air supply.

 

[Akimbo]

A major CO threat!

Not to mention a fire risk. We installed a Russian masonry stove and a Rais Danish wood stove. Both meet strict California clean air requirements, have outside air intakes, and are well sealed from indoors. Both are in public spaces instead of bedrooms. We are in the sticks and have it for heat backup and ambiance. A boiler failure or inability to get propane delivery could last weeks. In any case, fires are out and coals are cold before shutting the hatch on top of the chimneys and going to bed.

How long have you had those?

Eleven years. Hard-wired alarms are powered by AC with individual battery backup. All smoke and CO alarms are wired together by code so every #!X% one goes off at the same time with any single failure. We have 14 alarms and one failed about a week after we got our occupancy permit... at night and more than 13'/4M off the floor of course. My wife and the cat had to evacuate and sit outside in a car. I put on hearing protection after making sure it was a false alarm to isolate the problem. Fortunately I wired them in a home-run instead of the more common daisy chain. That allowed me to open a panel and quickly isolate one at a time.

They all get replaced on the next battery change. A failed sensor or battery is impossible to ignore, but also impossible to troubleshoot by following the sound with all of them blaring.