Actually there are two different types of CO detectors there. The first is a smoke detector. We had the Kidde KN-COP-IC CO detectors on each level of the house and when it came time to replace them (they're good for 7 years) we tried one of the new Kidde KN-COPF-i detectors as, being recessed, it hides better. We liked it so much we installed a second but used the cheaper one in the basement. We do have a third type. Its the Kidde KN-COSM-IB combo smoke/CO detector that speaks the type of alarm: it says fire or carbon monoxide so you know more quickly what potential emergency you are responding to. As everything is hooked into one circuit, they all communicate with each other.

I recentky installed 11 Kidde PI2000 smoke detectors. These detectors have two sensors - a photo detector and an ion detector. I recommend that you get both - there was a post about this not too long ago on the building forum about people who's smoke detectors did not go off and were killed. We too know some people who had a fire in their house and the detectors did not go off either - luckily they escaped. I like the Kidde detectors because they are very slim (I do not have the battery backup option - my smokes are backed up by a power genarator) and they were also highly rated by consummer reviews. I recently got to see how well these detectors work when I first fired up my brand new direct vent wood burning fireplace. For the very first fire, they tell you to do it when the winodws are opened because they use a special paint that burns off. I had the windows opened but apparently not enough. Our smoke detectors sensed this stuff - probably the ion sensor. After that first burn, the detectors have not gone off when I have lit other fires so I am pretty sure they were detecting the fumes from the paint burn off. I was impressed. I am not sure about putting CO sensors in the garage - but if you have rooms above the garage I would definetly put one in there. I would also recommend putting one around your dryer if you use gas. Got another tip from the appliance guy who told us to make sure we put in CO sensors in our laundry room. I have used the plug in modules that you can buy at HD - but now I have intregrated CO sensors into my security system. The new units are GE 250's i believe. Spend a few extra dollars and get the dual sensing smoke detectors - I paid 25 bucks each. In the grand scheme of things, it's peanuts to pay for the extra protection you get.

You have to be careful what you spray around smoke detectors etc, you could damage some sorts of sensors, don't forget those cans of 'air' contain anything but, usually just propellant - sometimes even flammable. I prefer a vacuum myself.

I did it because it is a requirement, not because it was a good thing to do. And again I say, "How do they enforce Code ON ANY modification or requirement if they do not have a reason to inspect?" This is no different then any code requirement, even if no inspection is called for. Other ways that it would be found out is when you sell, when the Insurance Company doesn't pay. When family members don't come to the funeral nor look you in the eye after the fire. In many jurisdictions here, the Fire Department will provide and install the new code compliant detectors at no cost. (They likely seen the results of faulty or non-existent detectors.) To challenge a safety improvement/requirement seems something that a rational person would not do. PS If you go to sell your home, you would have to disclose the fact that the Fire Detectors were not current code compliant. If you were not aware, the Realtor surely would be. If not, the Home Inspector would not leave him self open to future litigation should a non-compliant house he inspected were sold and subsequently a fire was shown to have been made worse by faulty ire Detectors.