If you can afford just one detector a photoelectric is recommended. When smoke enters the detector, light from the beam is reflected from the smoke particles into A photocell sensor and the alarm is triggered. The ionization chamber smoke detector has a small radiation source that produces radioactive material, electrically charged air molecules called ions. These ions cause a small electric current to flow in the chamber. Smoke particles entering the chamber attach themselves to the ions, reducing the electrical flow.
Heat detectors are no substitute for smoke detectors.
They set off an alarm in response to heat only. They do add protection and can be helpful in basements, kitchens, attics and garages. For Life Safety be sure your home is protected by a Smoke Detector. Operated Hardwiring supplies power to the detector from the building's main electrical source and requires electrical expertise to install. Battery Operated Battery powered detectors come with instructions for easy mounting.