Cleaning fans on a regular basis is a task that needs to be taken seriously. A dusty fan can cause not only allergy problems, it can also be a fire hazard.
Bathroom ceiling fans, I have recently learned through searching the Internet, are a particularly high hazard fan. Firehouse dot com is one of many websites where you can read about dust and bathroom ceiling fan hazards. I'm still researching what breathing in cellulose insulation that leaks through outlets and ceiling fans does or doesn't do to one's health.
After months of a tight chest and sneezing, I thought its just my allergies until I notice its getting worse. Why? I began to question if the allergy issues have anything to do with the fine gray dust that builds up so quickly since the renovations last year. I decide its time to buy a room air filter. Then...
I dust regularly. I know what dust build up to expect. This time dusting the 24/7 bathroom ceiling fan results in big chunks of fine gray dust falling. I know at least in November or at early October at the most, I dusted the vent. A flashlight shows me inside the vents there is also dust caked on what's up there. Checking the breaker box I find a warm breaker that happens to be to the bathroom light. I shut it off and the bathroom ceiling fan stops. And it will stay off until the ceiling fan is cleaned, and the sealing around the fan is inspected.
If you have bathroom ceiling fans, then I hope you have them serviced and cleaned regularly.
Update...Fan was cleaned with a vacuum and brush, no wipe down. After a day or so, allergy symptoms return; shut it off, and allergy symptoms better; turn back on and allergy symptoms return; and now the fan is off and allergy symptoms associated with its use have not returned.