First thing I have to mention is that was a firefighter for 10 years and I cannot stress the importance of these devices. A couple of years into this profession I responded to a house fire that unfortunately ended with the loss of two young children. This event compelled me to use my sign making abilities to create kits and props for not only my fire department but for fire departments across North America to educate the public on fire safety. People spend thousands of dollars insuring items in their homes and some will neglect to spend $15-$30 on a smoke alarm that is insurance to save a life.
You should have a smoke alarm outside of each sleeping area and on each level of your home. If you sleep with your door closed it would be a good idea to add one in your room as well. I personally have 7 smoke alarms throughout my home all costing about $15 - $30 each. You should replace these devices every 10 years or so. You can purchase fire alarms that detect both smoke and fire (dual sensor smoke alarms). If your cooking sets off the alarm you may wish to consider purchasing a smoke alarm that has a silence button. When you push the button the alarm will be silenced for a period of time so that you do not have to frantically fan it or do something bad like taking out the battery. Some home alarm monitoring systems may be able to have detectors for fire added to the burglar system so your house is monitored for both. I have to also mention that you should have a carbon monoxide detector as well.
Personally, I use the smoke alarm that came with the unit and plan on adding a second unit as a backup.
Remember to test your alarm(s) regularly and replace your batteries at least once every year
. For more information on smoke alarms visit the U.S. Fire Administration's web site by clicking here
Hope this helps. Stay safe --Rob