Jump to content

CO/Smoke Detectors


DonTx
 Share

Recommended Posts

The way I understand it is that CO is heavier than oxygen and will start to pool at the floor and work it's way up. Kinda like "filling" up a room or home.

If this is so...why are smoke detectors combined with CO detectors (other than financial reasons).

Some builders are putting these combos in their new home while other are putting the CO detectors next to the smoke alarms. Shouldn't the CO detectors be near the floor?

Donald

Link to comment
Share on other sites

Donald,

According to the CPSC fact sheet on CO -

CO alarms should be installed according to the manufacturer's instructions. CPSC recommends that one CO alarm be installed in the hallway outside the bedrooms in each separate sleeping area of the home. CO alarms may be installed into a plug-in receptacle or high on the wall because CO from any source will be well-mixed with the air in the house. Make sure furniture or draperies cannot cover up the alarm.

You can see the Fact Sheet at http://www.cpsc.gov/cpscpub/pubs/466.html

Link to comment
Share on other sites

Donald,

When leaking out of a combustion appliance, CO is mixed in with all of the other heated combustion products and will very likely rise. t might stratify in a lab, but I don't think that happens in real homes. I think a CO detector is a good idea and I recommend they be installed in nearly every house.

Thanks Steve, for the CSPC link to check out.

Link to comment
Share on other sites

Originally posted by Donald Lawson

The way I understand it is that CO is heavier than oxygen and will start to pool at the floor and work it's way up. Kinda like "filling" up a room or home.

Donald

CO has a density of .97 compared to air. In other words it's only slightly heavier. It mixes in with the air rather evenly due to convection and air movement. Also, the CO is not produced by itself, it's mixed with Nitrogen and Water vapor, which dilute it even further. Doesn't matter where you put the detector, it will see the CO.

Link to comment
Share on other sites

Originally posted by Donald Lawson

The way I understand it is that CO is heavier than oxygen and will start to pool at the floor and work it's way up. Kinda like "filling" up a room or home.

First of all, air is only about 20% oxygen. (It's mostly nitrogen.) The difference in weight between CO and air is very slight.

Next, gases tend to diffuse into each other anyway, regardless of their weights. (Do you hear about people getting worried about the oxygen in a room floating to the top and the nitrogen settling to the bottom?)

If this is so...why are smoke detectors combined with CO detectors (other than financial reasons).

Some builders are putting these combos in their new home while other are putting the CO detectors next to the smoke alarms. Shouldn't the CO detectors be near the floor?

Donald

There's no valid scientific reason to put them high or low. If you wanted the earliest possible warning, I suppose you should put them in the place where you suspect the gas will originate, like in the airstream of a supply register.

If you wanted the greatest safety level for the occupants, you'd suspend them in front of the occupants' faces.

- Jim Katen, Oregon

Link to comment
Share on other sites

I have the CO Experts model in my house, and I recommend it to every client with a potential CO producer in the house. It's the only low-level detector I know of, much better protection than any Wal-Mart special can provide. That's especially true for kids, the elderly, and those with respiratory problems Read all about it here

www.coexperts.com

and download the PDF brochure at the bottom of the page if you want. I print it out and include it with the inspection report. They can usually be had for about 90 - 100 bucks on the internet.

If your client has kids, tell 'em the little people could be subjected to constant low-level CO for the entire winter and thier $20 cheapie would never say a word. Most don't alarm until about 70 PPM, but this one starts beeping at 10 PPM and gets more insistant as the level rises. Your clients will love you for it, and it's far better CYA for you than looking for a crack in the heat exchanger or taking a one-time reading.

I also carry it in my bag when I work. Twice it's gone off sitting in the bag in a sellers house (once in the truck behind a smokin', stinkin' jalopy). [:-crazy]

Brian G.

Link to comment
Share on other sites

  • 3 weeks later...

Co Detectors should never be placed in a room where any gas burning appliances are at, or near the garage. The first few minutes any appliance kicks on, the co levels are higher than normal. About 5 minutes later though, those levels drop as fast as someone holding a bag of groceries and the bottom rips open. Co Detectors can give a false reading in the first few minutes. I had one just last week sound off, as the water heater kicked on-the detector was plugged in the wall, about 5 feet from it.

Gordon

Link to comment
Share on other sites

Originally posted by Gordon

Co Detectors should never be placed in a room where any gas burning appliances are at, or near the garage. The first few minutes any appliance kicks on, the co levels are higher than normal. About 5 minutes later though, those levels drop as fast as someone holding a bag of groceries and the bottom rips open. Co Detectors can give a false reading in the first few minutes. I had one just last week sound off, as the water heater kicked on-the detector was plugged in the wall, about 5 feet from it.

Gordon

It depends on what you want the CO alarm to tell you.

After all, it isn't really a "false reading," you're just percieving it as a nuisance.

If that was a standard-issue alarm that went off near the water heater, I'd be concerned. They only sound when exposed to CO for quite a while.

- Jim Katen, Oregon

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...