The Kidde KN-COSM-B is a combined Carbon Monoxide and Smoke Alarm in a single unit.
I had deliberately not included any of these type of alarms on this website previously because although they are perfectly acceptable units, the optimal position in which to place a smoke alarm and a carbon monoxide detector are different - the CO Alarm works best when positioned somewhere between eye level and two feet below the ceiling, while a smoke alarm works best attached to the ceiling itself.
A detailed explanation of why this is the case can be found here.
That being said, after receiving several emails suggesting that I should include a combined CO & Smoke Alarm, I've decided to present the facts to you, and let you make your own decision.
It uses 3 AA batteries - it warns you when the batteries need replacing and it has a fail-safe measure which prevents it from being attached to the ceiling without the batteries installed.
Because you will attach these to your ceiling, the Kidde KN-COSM-B has a built in voice which tells you if you have an emergency due to smoke or carbon monoxide to help you take the appropriate action in response to the alarm sounding.
It remembers the peak CO readings it's taken so when you press the test button it will tell you if levels have exceeded 100ppm - you can then have your fossil fuel appliances such as gas cookers or heaters checked to see if they are malfunctioning.
The smoke alarm can be temporarily silenced in the event of a non-emergency such as burnt cooking setting it off.
It comes with a 5-year warranty.
- Because you need multiple units throughout your home, the combined Smoke & CO Alarm saves you money.
- As far as combined Smoke & CO Alarms go - this is one of the most popular on the market.
- It has over 1,000 customer reviews with a 4½ Star rating on Amazon.
- It may not detect low levels of Carbon Monoxide Gas in some situations due to its placement on the ceiling.
Although the ceiling is not the optimal place to put a CO Detector, it is certainly a better place than none at all. For those of you on a budget it is much safer to get a combined alarm like the Kidde KN-COSM-B than to chose to install only a Smoke or CO alarm separately.
Click here to purchase this product on Amazon.
Please ensure you have enough alarms to protect your entire home - more than one are needed in the vast majority of dwellings - see Places within the home where CO Detectors must be installed.