MichaelMerino's blog

Smoke Alarms


There are basically two types of fire; flaming and smoldering. Thus, there are two recognized types of smoke alarms; photoelectric and ionization. You guessed it, each one is geared to work better depending on the type of fire. Either type will give you enough time to escape for both the smoldering and flaming fires. But having both types is best.

Ionization alarms work better in flaming fires and photoelectric work better in smoldering fires.

Ionization type smoke alarms have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm.

Photoelectric type alarms aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.

The best protection is to have both types of alarms installed. You can also purchase a dual alarm that uses both technologies.

I also like the idea of having the alarms interconnected or hardwired to each other, with a battery backup. This way if one alarm sounds then all alarms sound. There are some new alarms available that are wireless and will activate all alarms, but this is a newer technology and I do not believe it to be as reliable as hardwire.

Place an alarm in each sleeping area as well as outside every sleeping area. There should be one on every level including the basement.

When I inspect a house I report on the presence or absence of smoke alarms. I also test them, with a disclaimer to my client. The test only tells me that the batteries work. It does not tell me if the detector functions. In order to really test the smoke detectors, I would have to smoke up the house. of course most sellers do not want their house smoked up. I suggest to my clients that they have the smoke alarms replaced. This is a small investment for a life-saving precaution.

Some municipalities are now requiring sprinkler systems in residential building codes. I will cover this topic in the near future.


Cook, DuPage, Grundy, Kane, Kendall, Kankakee, and Will.

Alsip, Berwyn, Bolingbrook, Bourbonnais, Channahon, Chicago, Chicago Ridge, Crestwood, Crete, Downers Grove, Frankfort, Homewood, Homer Glen, Homewood, Joliet, Lemont, Lockport, Lombard, Kankakee, Manhattan, Midlothian, Mokena, Monee, Naperville, New Lenox, Oak Brook, Oak Forest, Oak Lawn, Oak Park, Orland Hills, Orland Park, Palos Hills, Palos Heights, Palos Park, Plainfield, Posen, Woodridge, Romeoville, Steger, Tinley Park Home Inspector

Merino's Home Inspection & Education Inc.
9029 Pebble Beach Lane
Orland Park, Illinois 60462

Orland Park home inspector
Tinley Park home inspector
Illinois Home Inspector License 450.010091
Illinois Home Inspector Entity License 451.000851

Syndicate content