Attic Ventilation

Improve your attic with effective moisture control and heat reduction

What does attic ventilation mean to you?

Attic ventilation means different things to different people. Interpretations definitely vary. With such broad usage, information about attic ventilation can be confusing or misleading. Let’s clarify what it means to ATMOX and in turn for your home. Ventilation with ATMOX means using fresh air from outside pulled through the attic by fans.

The goal of attic ventilation is to reduce heat and moisture. Heat issues are most common during summer months. Alternatively, moisture issues tend to surface during cold winter months.

Attic fans that are properly controlled allow for targeted air exchanges to improve the conditions within the attic.

Proper ventilation is key in reducing the negative side effects of attic heat and moisture.

ATMOX Graphic of Heat and Moisture in the attic

ATMOX Controller Advantage


Address attic moisture concerns

ATMOX icon for crawlspace and attic moisture control

Reducing moisture in the attic is all about preventing condensation on attic surfaces that can lead to mold or wood rot. The ATMOX controller directs the exchange of air to expel moisture buildup. Moisture levels are compared through a dew point comparison to dry effectively when outside air is drier. Therefore, ventilation is used to improve conditions only when beneficial.

Reduce attic heat

ATMOX ico for attic heat reduction

The ATMOX controller uses temperature data from the highly accurate sensors to reduce heat with outside air. Furthermore, the controller directs ventilation beyond a simple heat trigger to reduce temperature further by running at night or when cooler.

Create a healthy home with improved air quality

ATMOX icon for air quality in attics and crawl spaces

The air is exchanged when beneficial to reduce moisture and heat and improve air quality. The air exchange dispels odors, toxins and material off-gasses to the outdoors with fresh air exchange.

Positively affect your home’s energy usage

ATMOX icon for attic and crawl space energy efficiency

At the core of all product design, the focus is on energy efficiency. The goal is always on reducing overall energy usage within a home. Therefore, a key component is to make the fans themselves very energy efficient. For example, each ATMOX fan only uses 15 watts of power when running! The use of ventilation lessens the use of air conditioning with reduced attic temperatures.

Bring drying to all areas of the attic

ATMOX Distributed Airflow Icon

Most attic setups use several ATMOX fans spread out across the space. The goal is twofold. Firstly, air needs to blow across all areas of an attic, especially in situations of moisture buildup and potential condensation. Secondly, the exhaust fans should not overpower the ventilation. It is important for the air to be coming through intake points to the outside and not from air within the living space.

ATMOX Attic Products for Attic Ventilation

Picture of ATMOX APEX Controller - Attic Fans Connection Highlighted

Attic fans will be connected to the ATMOX controller through the use of the Attic Fan output. ATMOX attic fans will receive both signal and power from the controller.

For more information – learn more about the ATMOX Attic Fans.

Why should you care about heat and moisture in the attic?

Attic Moisture

Do you see condensation on your roof decking or is mold or wood rot visible in your attic? Reducing moisture in the attic is all about preventing condensation on attic surfaces that can lead to mold or wood rot. 

Most moisture issues start from within the living space from normal everyday activities such as cooking, showering, cleaning or using a humidifier. This moisture rises with warmer air and can escape into the attic. Once it is in the attic, it sometimes gets trapped. Therefore, this moisture needs to be ventilated to the outdoors. If the attic is at a cold temperature, the air can’t hold a lot of moisture. It will quickly start to condense on any cold surface just like a glass of ice water outside on a hot day. That condensation is dangerous if it sits there for too long. Removing the wetter air prevents mold growth within the attic.

Attic Heat

Is your air conditioning struggling to keep your home comfortable? Reducing heat in the attic is all about energy efficiency and protecting your home.

When you reduce the temperature in the attic, it limits the temperature transfer to the living space. That excessive heat can create a heavy workload on your AC unit. In turn, the air conditioning is either going to run more than it would otherwise or it may not not be able to keep up with the heat. This problem is often evident in a two-story house with one AC unit. Ever been in a house with a hot upstairs? Attic heat can definitely be a contributing factor. Obviously, overuse of an HVAC system is never efficient and can be very pricey when you get the electric bill.

As a homeowner, you want to protect the investments that you have made in your house. Your roof is a big part of that investment. As the heat in the attic increases, the potential for damage to your roof also goes up. Asphalt shingles will deteriorate in extreme heat generated directly from the sun and from below in the attic. HVAC equipment is another large investment. These and other electrical and mechanical components in the attic can have issues under extreme heat. And, of course you want to protect the items that you may be storing in the attic. You don’t want to melt or destroy your childhood mementos or holiday decorations that inevitably get thrown in an attic for safekeeping.

Active vs. Passive Ventilation

It is well established that an attic needs ventilation with fresh outside air to increase energy efficiency, protect your home, and improve air quality. 

There are two types of attic ventilation: active and passive. Active ventilation, sometimes referred to as mechanical, is the process of assisting air movement and circulation from soffits or another intake points and exhausting out at the highest points of the attic. Passive ventilation is simply open intake and exhaust points with no mechanical assistance to increase air circulation or air exchange. 

Although the passive ventilation option may seem simple and energy efficient, there may not be enough ventilation. According to the Department of Energy, “In warmer climates, natural ventilation can’t circulate enough air through a home to provide sufficient cooling at night to remove the day’s heat.” 

The benefit of active ventilation is the increased rate in which fans can move air. Therefore, the faster turnover keeps heat and moisture from building up in the attic.

Installing soffits on a house for attic ventilation

ATMOX Smoke Test Comparison

Watch this video showing a comparison of air movement using smoke. 

The Left Side with Blue Smoke is the Passive Ventilation Side. The Right Side with Green Smoke shows Active Ventilation using ATMOX fans underneath the ridge vent to supplement the natural movement of air. 

The difference in air turnover within the attic is significant. Consequently, that slower air movement with passive ventilation allows for more significant heat buildup.