Ventilation

I am doing some work in my bathroom this week and installing a bathroom fan. Ventilation is often overlooked or done improperly, so this weeks Sustainable Saturdays is about installing a proper vent in your bathroom. I will cover other vents for the kitchen in a later article when I take that on this spring. Ventilation is an important about keep the IAQ safe for your family. If done improperly it can cause more problems than it will solve, so I wiil cover the basics.

Many older homes do not have a vent in the bathroom as a widow was considered adequate. In the summer here in Michigan I tend to keep my windows open most of the season unless it gets really hot and humid. I prefer fresh air but in the winter that is not a viable option. Installing a properly sized ventilation fan in your bathroom can be done in an afternoon with moderate mechanical and electrical skills. There will be a more detailed instruction in the project section soon, but this will help you start the planning and purchasing of the proper ventilation system for you bathroom.

A little about ventilation fans, they are rated in a couple ways. CFM is cubic feet per minute and you want your bathroom to have 8 air changes per hour. With a little math that is pretty easy to figure out and will be covered in the project section. For most bathrooms with 8' ceilings you can use the square footage as a guide. a 8x6 bathroom (like mine) will be fine with a 50 CFM fan (8x6=48), with eight foot ceilings that covers the eight air exchanges per hour (48x8=384, 384/8=48), makes it a little easier.

Next is how loud the fan will be. A cheaper builder grade fan is louder than a more expensive quiet fan. Sones are used as a comparison so you need to experiment with what you are comfortable with having. Since I only run the fan when necessary that does not bother me very much but it may annoy you. Usually a quieter fan is a better built fan, but not always.

Venting the fan outside is essential for the health of you and the home. Never vent a fan into the attic because it will create many problems including not working properly. It is best to run the vent out a side wall, but that is not always possible. The next best choice would be through the soffit if you can do that away for the attic soffit vents. Lastly, you can vent through the roof if absolutely necessary. Personally I do not like roof vents because they eventually fail causing the roof to leak. It is common practice to vent though the roof because is is the cheapest way to get it done especially in new construction.

Adding bathroom ventilation helps reduce the possibility of mold in the bathroom and stale odors from accumulating. When properly done it will improve your IAQ significantly helping the whole house. Improperly done it can create many more problem than it will solve so please be careful. I will soon have a more in depth write up on installing bathroom ventilation.