We had a small electrical fire in our garage in Los Angeles last week and now the smoke smell has permeated the house particularly the living room which is the closest area. I have a powerful Levoit Core 400S and I have been running it on the highest setting for two days straight but I can still faintly smell the smoke especially in the morning. I am wondering if the air purifier is the right tool for this kind of intense odor problem or if I need to look at professional solutions. Does the HEPA filter capture the smell or is it the carbon part that handles smoke odor and maybe mine is already saturated? What are the best methods for using an air purifier to completely eliminate a lingering smoke smell from a room?
Yes an air purifier with a robust activated carbon filter is absolutely the right tool for removing smoke smell but you need to understand that smoke is both particles and gas. The HEPA filter catches the microscopic soot particles which is the visible smoke but the activated carbon layer is what chemically traps the odor molecules which cause the smell.
For an intense smoke odor problem like yours a standard air purifier filter might be overwhelmed if it has been used for several months already. The carbon layer has a finite capacity and if it is near saturation it cannot absorb much more. You should immediately replace your filter with a brand new one maybe even one specifically designed for smoke or VOCs to maximize the carbon absorption.
Smoke odor is notoriously difficult because the odor molecules bond to surfaces like fabric carpet and painted walls which the air purifier cannot clean. The purifier cleans the air only. You need to combine running the purifier on high with deep cleaning and airing out the room for the best results against lingering smells.
Make sure you are running the purifier in the isolated room where the smell is strongest. Shut the doors and windows to that room and run the unit on its highest setting for several hours straight. This ensures the highest Air Changes Per Hour rate to cycle the air as many times as possible through the carbon filter.
I had a similar issue with a small kitchen fire and I found that placing bowls of baking soda around the room helped to absorb the odor from the surfaces while the air purifier handled the airborne molecules. It is a long process but the combination of surface absorption and air filtration works very well.