Hi @Mike272,
I just answered your question in the other thread. Hopefully it’s helpful! I see this one as a two-part question:
- What’s the optimal (certified) carbon monoxide alarm setup?
- Are low-level CO alarms useful/worth having?
I’ll address no.1 first, as I believe it’s more important. Please note that these findings are only from my research, and I am by no means an expert here.
When it comes to CO monitoring, the EPA recommends one CO monitor per floor (see here: Where should I place a carbon monoxide detector? | US EPA). They also state that if there is only a single monitor in your home, it should be near the sleeping areas.
Other sources, like the Scottish Fire and Rescue Service recommend one alarm in every room where there is a carbon-fueled appliance (gas heater/stove, fire, boiler, etc). To lean on the side of safety, I think this is a much better approach. You could even go further if you wanted, and add a device in every room where there is a carbon-fueled appliance or where someone sleeps.
Based on the information from these organisations, it seems like the bare minimum should be a monitor near sleeping areas (such as a hallway that bedrooms are accessible from). Stepping up from this, one monitor in every room where there is a carbon-fueled appliance is far more thorough. For the safest approach, you might want to consider one monitor per sleeping area and one per room with a carbon-fueled appliance.
These are the emergency monitors, and they should be certified. You can learn more in this thread:
Basically, you will want to ensure these carbon monoxide monitors are UL2034 certified. With that said, these monitors are only the emergency monitors, and they aren’t very sensitive. This is where the second question becomes important - are low-level CO detectors worth having?
You pretty much said it yourself that they are an extra level of safety. If you have a lot of gas-powered appliances (as you mentioned you do), I think having at least one low-level carbon monoxide detector in your home would be a good call. Ideally, this could be placed somewhere near your sleeping areas. If you don’t mind spending a bit more, a couple of these devices could also be worth having (perhaps one in the kitchen/living area, and one near the bedrooms). These devices do tend to be quite a bit more expensive than the UL2034 devices, unfortunately.
Personally, at my home, we have two emergency alarms (one in the hallway from which the bedrooms all branch off) and one in the living area. Our house doesn’t have gas appliances, however, and the only potential CO source in the house is a fireplace in the living room. On top of this, I have a single low-level carbon monoxide alarm in the living room. I would love to add more low-level alarms, but as mentioned, they can be a bit costly.