What Is a Whole House Ventilation System?

Maintaining a healthy and comfortable home isn’t just about heating or cooling – it’s also about proper ventilation. A whole house ventilation system plays a key role in ensuring your indoor air is fresh, clean, and well-circulated. If you’re unfamiliar with this concept, HVAC.com explains what a whole house ventilation system is, how it works, and why it may be a smart investment for your home.

What Does a Whole House Ventilation System Do?

At its core, a whole house ventilation system improves indoor air quality by exchanging stale indoor air with fresh outdoor air. Unlike simply cracking a window, these systems provide a controlled, consistent flow of air that prevents pollutants, moisture buildup, and odors from lingering inside your home.

Whole house ventilation systems go beyond basic air exchange – they regulate airflow to ensure your home gets the right amount of ventilation without compromising energy efficiency.

Types of Whole House Ventilation Systems & How They Work

Exhaust Ventilation Systems

Exhaust ventilation systems remove indoor air, creating negative pressure inside your home. This pressure difference draws fresh outdoor air into the home through intentional vents or natural leaks in the building’s envelope, such as around windows and doors.

Exhaust fans are installed in key areas like bathrooms, kitchens, and laundry rooms – places where moisture and odors are most prevalent. These fans run continuously or on a timer to expel stale air. 

Supply Ventilation Systems

Supply ventilation systems work by introducing fresh outdoor air into the home while allowing stale air to escape through intentional exhaust vents or natural leaks. This creates a slight positive pressure in the home that prevents outdoor air from entering through undesirable pathways like cracks or gaps.

A fan pulls outdoor air through the ducts and distributes it throughout the home. Air filters can be added to remove allergens, dust, or pollutants before the fresh air enters the living space. Meanwhile, stale air exits the home passively, without the use of exhaust fans.

Balanced Ventilation Systems

Balanced ventilation systems equally pull in fresh air and expel stale air to maintain neutral air pressure throughout the home. These systems combine exhaust and supply ventilation to ensure air exchange occurs evenly across all living areas.

Two fans operate simultaneously – one draws fresh air into the home and another removes stale air. These fans are connected to separate ducts, which can be strategically located to target specific rooms like bedrooms and common areas for fresh air intake and kitchens or bathrooms for air exhaust.

Heat Recovery Ventilators (HRVs)

HRVs are designed to transfer heat between outgoing and incoming air, making them ideal for homes in regions with extreme temperature differences between indoor and outdoor environments.

During the colder months, HRVs extract heat from stale indoor air before expelling it outside. This heat is then transferred to the incoming fresh air, warming it up before it enters your home to reduce the workload on your heating system. In warmer months, the system works in reverse by transferring heat from incoming air to the cooler outgoing air. This way, the hot outdoor air doesn’t add to your cooling load.

Energy Recovery Ventilators (ERVs)

ERVs perform a similar function to HRVs but with an added capability: humidity control. These systems are perfect for climates where managing indoor humidity is as important as maintaining temperature comfort.

Along with heat, ERVs transfer moisture between outgoing and incoming air. In humid climates, they remove moisture entering with the fresh air and expel it with exhaust air. In dry climates, ERVs help retain moisture inside the home by extracting it from the outgoing air and adding it to incoming air. This dual control of heat and moisture ensures consistent indoor comfort.