Frequently Asked Questions about Whole House Fans

Typical Whole House Fan Functionality:

If you are not familiar with how a typical whole house fan works, current whole house fans are cut into your ceiling in a strategic location of your home. The purpose is to bring outside air into the home (at a high volume) when it’s cooler outside than inside, flooding your home with cooler air. To do this, current whole house fans rely on you to know when it’s cooler outside, and to open a window or door to bring in the cooler air. The fan will turn on, via a timer or remote, and pull outside air into the home and flush the heat out through the attic, thus removing the heat lid and allowing more heat to rise from the living space and infiltrate into the attic. This helps to create a better conditioned space and reduces energy usage on your HVAC system.

Top concerns about whole house fans we heard during our 30 years in the HVAC field:


Customers complained that they had to be home to open a window or door (to let air in), and could not leave while the whole house fan was running for fear of being broken into.

CentraVent’s Filtered Free Cooling (FFC) system allows you to run the whole house fan without opening windows or doors. We bring fresh, filtered air into your home. With our patented lighted, easy-access, filtered ceiling vents and our filtered damper cabinet. CentraVent’s CentraFlow (CF) also allows filtered fresh air to be pulled in by the CVT Green Cooling Fan (GCF) and distributes it through all your existing HVAC supply vents. You can rest assured that your home will stay safe and secure with the CVT FFC & the CVT CF.


Typical whole house fans bring in outside air and everything in it. Customers complained of horrible allergies and an increase of dirt and dust through out their home while using the whole house fan.

The CVT FFC or CVT CF system is designed with 5 round – 12” washable filters that are conveniently located in the CVT Ceiling Vents.


Customers with programmable wall switches would come home after a power outage and find their whole house fan running while the HVAC was on at the same time. Basically, they were cooling the outdoors. This happens a lot if you do not reset your timer to the current time immediately after the power outage.

The CentraVent Green Cooling Fan (GCF) is controlled by our easy-to-use APP and can be controlled from anywhere. In the event of a power outage and there is no internet, the GCF can be easily run from a generator and controlled by the CVT wall switch in default mode.


Reference #3- There is no way to make sure the HVAC doesn’t turn on while running the whole house fan, other than walking over to the thermostat and shutting it off.

Because CentraVent is incorporated into the HVAC system, we wire right into it. Our patented software can read what the HVAC system is doing along with reading indoor and outdoor temperatures. Our software (along with the parameters that you as the customer have chosen) will determine the best function based on efficiency and user settings. The two systems cannot run at the same time. In the event of some type of failure, the system will default into HVAC mode.


Customers said they would prefer not to cut a new large hole in their ceiling, especially for a device they don’t use year-round.

CentraVent’s patented Green Cooling Fan (GCF) is the only plenum resident whole house ventilation fan in the world. It easily fits into most ceiling return air filter plenums. This means no new holes in your ceiling need to be cut.


We have had customers that turned the HVAC off at the thermostat, let the whole house fan run during the night and forget to turn the HVAC back on before going to work. They return home to a house that is over 90 degrees inside. This is not only inconvenient but could be deadly to your pets and expensive to try and catch up to your desired temperature and hard on your HVAC system. (hot outside & hot inside).

The CentraVent App can control the CVT from anywhere and has what is called the Eco-mode. This eco-mode allows the homeowner to choose and run a schedule and parameters automatically. So, this will not happen with the CVT Green Cooling System.


Do I have to get into the attic to change the filter?

With the CVT FFC system, the filters can be installed in our patented easy access ceiling vent housing units (CVT LRV & SRV) by easily turning and removing the ceiling grill and accessing the filter from inside the house.


My current whole house fan will not work with my generator when a power outage occurs.

The CVT Green Cooling System was designed with this in mind. At 4000cfm the CVT GCS runs at a low 372 watts, making it extremely efficient to run. At 50% fan speed, the CVT GCS runs at 2000cfm and only consumes the same amount of energy as 1.5 light bulbs making it one of the most eco-friendly whole house ventilation systems on the market.