Whole House Fans: Proper Attic Ventilation and Requirements
A whole house fan can be a total game changer when it comes to cooling your home. After installation, many homeowners have reported two huge impacts. One is that they’re using their air conditioning less. Another being that their monthly electric bill has gone down significantly. In addition to the benefits provided by a whole house fan, there can also be potential issues if not installed properly.
When having a whole house fan installed in your attic space, something you do not want to encounter is negative pressure. Now keep in mind that this ventilation system is designed to move air from your house into your attic. Since just about all attics are vented, the pressurized attic air is then naturally pushed outside through those vents. However, without enough venting area, pressure can build up. This causes the airflow to slow down and become less efficient. Even worse, it can result in potentially pushing hot attic air and dangerous fumes back into your living spaces. This negative pressure can create havoc in your attic and home. Luckily, there is a fairly simple solution to this problem.
Airflow is measured in Cubic Feet per Minute (CFM). The higher the CFM, the more venting area is required to keep the system working efficiently. A rule of thumb is that you should have one square foot of “net free venting area” for every 750 CFM of airflow. So at 3000 CFM, you’ll want four square feet of venting. Most modern homes easily accommodate this rule, but it is important to check to ensure optimum system efficiency. Not to mention, saving your attic and home from having harmful airflow and long-term problems.
Whole House Fan Installation Suggestions
The first step in creating the right environment for your whole house fan is to purchase your system from a company that not only can install the unit but can also check for feasibility. The professional installing your ventilation system should be looking for adequate attic ventilation before things get started. After the assessment, double check to make sure they have done the correct calculations for your venting needs. If the installation company tries to tell you proper ventilation is not a big deal, they are not a dependable company. Having significant ventilation can make or break your whole house fan experience. Once it’s done right, the rest is a breeze.