Photoelectric smoke alarms are not as common in modern construction. They work on a different principle than the more common ionization alarms (see infographic below). Photoelectric alarms are better suited to detecting smoldering type of fires in a home.
Just like the post last week on ionization alarms, the takeaway for a homeowner is to consider a dual type of alarm instead of relying on just one method to detect fires in the home. You don't get to choose the type of fire that may affect your home. Dual type smoke alarms that combine both ionization and photoelectric sensors are the best choice for any alarms you are considering replacing or upgrading.
Brian Jovag, owner of Jovag Home Inspection.