You can’t buy a new house that doesn’t have bathroom ventilation anymore. There are several good reasons why most building codes now require bathroom vent fans in new construction—and why existing houses that don’t have them ought to.
Bathrooms are a significant contributor to excessive indoor humidity. In today’s well-sealed, energy-conserving homes, moisture generated by bathroom activity accumulates instead of dissipating. Water vapor penetrates the structure of the house, as well as infiltrating adjoining rooms and the attic. This ongoing source of humidity creates a indoor breeding ground for toxic mold growth as well as deteriorates building materials and makes the home harder to cool in summer.
Fan Basics
In bathrooms without an openable window, installing a bathroom ventilation fan is the only viable method to exhaust damaging humidity before it permeates the walls and ceiling or moves into other living spaces. Here are some general vent fan guidelines:
- Fans are sized by air flow capacity, expressed in CFM (cubic feet per minute.) Generally speaking, a bathroom fan should provide one CFM of air flow per each square foot of bathroom floor space up to 100 square feet. For rooms larger than that, figure 50 CFM for each shower/bath enclosure and toilet and add an extra 100 CFM for a whirlpool bath or spa.
- A bathroom fan must ventilate water vapor all the way to the exterior of the house through a dedicated vent pipe. Simply venting into the attic is insufficient and actually deposits moisture in a zone where it may cause the most significant structural damage as well as trigger mold growth.
- Actuation of the fan can be provided by a manually-operated timer switch, a motion-detecting switch or a humidistat that senses increased humidity. Shutoff of the fan should be timed or automated to avoid over-ventilating that wastes energy and can contribute to depressurization of the interior of the house.
Paitson Bros. has served Wabash Valley homeowners since 1922. Contact us for more information about adequate bathroom ventilation in your home.
Our goal is to help educate our customers in Terre Haute, Indiana about energy and home comfort issues (specific to HVAC systems). For more information about bathroom ventilation and other HVAC topics, download our free Home Comfort Guide or call us at 812-645-6859.
Credit/Copyright Attribution: “Kevin_Hsieh/Shutterstock”
Jeff Paitson is a third generation business owner who continues to run the business with the same values that have been passed down from previous generations since 1922.
Jeff’s belief is that the business belongs to Jesus Christ; therefore 10 percent of the company’s profits go toward the Maryland Community Church.
Jeff is a Terre Haute Chamber of Commerce member and in his spare time, he enjoys 
Ethan Rayburn is a lifelong resident of Terre Haute and a 2005 graduate of Purdue University.
An Eagle Scout, Ethan spent four years as a non-profit executive with the Boy Scouts of America before joining Paitson Bros. as a comfort advisor and later General Manager. In that role, Ethan has brought a renewed enthusiasm for customer care, integrity, value, and service to Paitson Bros. Heating & Air Conditioning.
Ethan enjoys singing and was a member of the Purdue Varsity Glee Club. He also enjoys playing and coaching soccer, spending time with his family and two young boys, and volunteering his time and resources with his church, Terre Haute First Baptist Church, which he has attended from a very young age.
Paitson Bros
1 (812) 232-2347
Serving the Wabash Valley, IN Area Since 1922