When we discuss healthy homes, we always seem to start the conversation with moisture. Moisture that causes mold, that causes wood to rot, that leaves smells behind. And then we move to talking about the bathroom, where moisture is produced every day, like clockwork.
But what we don’t talk enough about is making sure that we deal with that moisture every day, like clockwork. And it usually comes down to two issues:
- The bath fan doesn’t work, or
- The bath fan operator doesn’t get it done
In the case of the bath fan not working, there are two options. The fan is simply not operating, has been disconnected, or is so loud that the occupants choose not to use it. The former two options are easy and straightforward. Fix the fan! The latter is a fairly common issue, and does not have to be. Bath fans are tested and listed with the Home Ventilating Institute (HVI). You can go to the HVI Certified Products Directory (https://www.hvi.org/proddirectory/CPD_Reports/section_1/index.cfm) and find a bath fan that provides quiet operation, as well as adequate airflow for your bathroom. The listings provide sound levels, power usage, and air flow in cubic feet per minute (CFM). This allows you to find an energy efficient, quiet operating, and adequately sized bath fan. Fans that meet the Energy Star rating for effieincy are also indicated. And additionally, there are good sections on the HVI website that help with properly sizing and installing bath fans.
Moving on to the operator error section, there are quite a few instances where moisture issues, and potentially mold issues, can result from occupants simply not following good practices with regards to bath fan usage. Failing to operate the fan, especially when running hot water such as when showering or running a bath, will result in high levels of humidity in the bathroom. This moisture ends up condensing on walls and windows, soaking in to towels and bath matts, and fogging the mirror. Left alone, this moisture causes musty towels, mold in and around the bathroom, and potentially rotting wood throughout the bathroom.
Simply following good procedures when using bathrooms can prevent all of these potential issues, while also keeping towels fresher, windows and mirrors clear, and occupants healthy. A few easy occupant guidelines:
- Operate the bath fan when showering or bathing
- Leave the fan on after completing the shower or bath. HVI recommends at least 20 minutes, and there is evidence that it is better to continue to exhaust from the bathroom up to two hours after showering or bathing. Moisture on towels, bath matts and in the shower or tub may take some time to dissipate. Use a timer if possible.
- Use an occupancy sensor with a built-in timer if possible, so that the fan runs automatically when someone enters the bathroom.
- And lastly, do not vent the bath fan directly in to an unconditioned attic! This practice is commonplace, and has been the cause of many, many mold issues in attics. Dumping humid, warm air in to an unconditioned attic results in that moisture condensing, and “raining” in the attic. Done consistently, this can have very bad consequences. Vent the bath fan to the outdoors, and you will not have any issue.
These are just a few important points to consider when installing and operating your bath fan. But the most important point of all is, use a bath fan! And keep your home healthy, comfortable and smelling good.
Contributed by Barry Stephens, East Coast Regional Sales Manager for Ventacity Systems, Inc. Barry is a member of the Board of Directors for the Maine Indoor Air Quality Council and resides in Scarborough, ME.