Was looking into dual smoke detectors, ionization & photoelectric type.  Am considering a Kidde Mdl #PI 2000 120V w/ battery back-up, but would rather have CO protection too.  Are there any out there with all three?

Well, how convenient!  The Google ads on the bottom of the page are all links to sites that sell smoke detectors.  I bet a phone call to one of them could give you your answer.  (A much better match than with the “odor” post!)

I have to admit to ignorance: is the normal cheap smoke detector both photoelectric and deionization-type?  If not, I should look into replacing mine.  My hallway has the smoke and CO detectors side by side, so I may as well keep it that way, unless I want to spackle those molly holes.

RedSleds - 07 December 2005 02:16 PM

Was looking into dual smoke detectors, ionization & photoelectric type.  Am considering a Kidde Mdl #PI 2000 120V w/ battery back-up, but would rather have CO protection too.  Are there any out there with all three?

Most of the major manufacturers have a combined CO and smoke unit, (Kidde, First Alert etc.) but I’m not sold on the idea, and here’s why…

Smoke rises, while CO is just ever so slighly heavier than air, so either lies low, or mixes somewhat throughout a room. This is why instructions for smoke detectors suggest installation either on a ceiling or high on a wall, while it is reccommended that CO detectors be installed at a lower level at the mid point on a wall. So a combined unit is (in my opinion) a compromise that tries to do two things at once, but does not neccesarily do them as well as seperate units might.

I guess in addition to this, if you had everything in the same unit and it fails (i.e. battery dies) you have no coverage, whereas with seperate units at least you would be covered for one or the other. Of course regular testing and changing of batteries on a regular anniversary date (your birthday, Jan 1, etc.) would cover this eventuality.

Just my 2 cents.

Willhound

I agree with every thing said the positioning is an issue. That said, having them wired in to all locations, the others in the home sounds the alarm from everyone, much harder to ignor, when all are going off at once. Combo might make more sense if hard wired

I think that carbon monoxide and air are almost the same density (CO might be a bit lighter).  CO tends to travel in the direction the air is moving, and if the air has been warmed the CO will rise.  When we go in to meter a structure we always keep the meters up high.  I went to a CO alarm this morning.  The homeowner had a dime-sized hole in the boilers flue pipe.  The highest readings we got were around 20 ppm, but the homeowner had vented the structure prior to our arrival.

Rick