You might be getting ready to buy your first home, your dream home or even renovating your current home and the builder starts talking about a continuously operating exhaust fan. Your first reaction might be – what’s that? You’re not alone. For many homeowners exhaust fans are something that just comes with the house and not much thought is given to them. As home building has advanced, so has the need for ventilation within the home. Lets take a look at a few reasons you do need a continuously operating exhaust fan, starting with what is it.
What is a continuously operating exhaust fan?
The name is fairly descriptive. It is an exhaust fan that is continuously operating to remove moisture and contaminates from the home and providing multiple air exchanges per day (about one air exchange every 3 hours). To maximize their effectiveness they are typically installed in a central location of the home such as a family or living room. Because they are located in a main living space, they are required to have a very low sound level – less than the sound of your refrigerator.
Why do I need one?
The importance of a continuously operating exhaust fan will depend on the age and construction type of your home. In the paragraph above we talked about air exchanges. This is actually part of the national building code known as ASHRAE 62.2. The purpose of the code is to make sure the air inside the home does not become “stale” and in some cases dangerous. Newer homes are now being built to higher insulation standards, which make the home less susceptible to drafts. This is a good thing. What happens however is that because the house is so tight, it doesn’t allow for fresh air to come in or stale air to get out. This is where the exhaust fans come into play and in some cases a fresh air intake fan. In older homes, they generally have more air leaks and a continuously operating exhaust fan might not be as crucial. A benefit of using an exhaust fan is it puts the control in your hand instead of depending on drafts or other factors to determine the quality of your indoor air.
What should I look for?
As we mentioned, for these fans to be most effective they need to be installed in a centralized room such as a living room or family room. Choosing a fan with a low sound level is important. Exhaust fan sound levels are measured in sones with one sone being about the sound your refrigerator makes. The building code calls for a fan with a sound rating of one sone or below. The lower the sones, the quieter the fan is. A second consideration that is just as important is to make sure the fan has enough airflow. Airflow is measure in CFM or cubic feet per minute. Air King provides an easy calculator along with ASHRAE 62.2 information here. It is important that you have enough ventilation without over powering it and causing a negative pressure in the home (exhausting more air than is coming into the home). A final consideration is that you want an energy efficient fan. Since it will be running continuously, you don’t want it to be a burden on your electric bill. Air King offers a wide range of ENERGY STAR® certified models to fit almost any residential home need.
For more information about Air King exhaust fan solutions as well as continuously operating exhaust fans and ASHRAE 62.2 building codes, visit airkinglimited.com.
