What is a Balanced Ventilation System?

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We spend almost 90% of our time indoors. We spend it in our rooms, sleeping or in kitchens, cooking homemade meals for our family. These daily activities can lead to stuffy air, especially with modern construction making homes airtight. Ventilation, and balanced ventilation at that, is essential. But what is a balanced ventilation system?

A balanced ventilation system is a mechanical ventilation system that works to balance out the air coming in and out of a building. This system neither pressurizes nor depressurizes indoor air. Instead, it exhausts and draws in volumes of air in approximately equal and controlled amounts at the same time.

Under the balanced ventilation system, there are two more options: an HRV or an ERV. There are also considerations of different types and designs. Of course, which ones you should pick and install would depend on what your home and family needs.

In the article below, we’ll go over what exactly a balanced ventilation system is and its benefits and drawbacks. We’ll also go over the system’s different types and designs and which homes they would be best for.

Proper Air Ventilation and Why It is Important

All homes and buildings need a continuous supply of clean and fresh air. Indoor air also needs to be free from dust, dirt, contaminants, toxins, and allergens so as not to cause asthma, allergies, and other respiratory concerns.

Traditionally, houses and buildings were intentionally constructed “leaky”, allowing some indoor air to escape out and some outdoor air in. But today’s modern homes are constructed to be as airtight and sealed as they can be. There is a clear absence of drafts and air leaks.

The thing is, daily indoor activities like cooking, washing and drying clothes, and showering and bathing lead to emissions and contaminants. This can make indoor air stuffy, dirty, and polluted, making it difficult to breathe.

A simple solution to this would be to crack open a few doors and windows to let polluted indoor air out and fresh outside air in. But by doing this, you could be very well throwing out hard-earned money for spikes on your heating and air conditioning bills.

Moreover, according to the United States Environmental Protection Agency (EPA), indoor air pollution is among the top five environmental risks to people’s health. And good indoor air quality (IAQ) is a major component of keeping a healthy indoor environment.

Ventilation plays an important role in keeping good and efficient indoor air quality. This is where mechanical ventilation systems, like a balanced ventilation system, come into the conversation.

What is a Balanced Ventilation System?

A balanced ventilation system is a mechanical ventilation system designed to balance out the amount of air coming in and out of the house.

This system exhausts and brings in approximately equal and controlled volumes of air at the same time. This means polluted and stale indoor air is removed from your house while at the same time, the same amount of fresh air is brought in from the outside.

When properly installed, a balanced ventilation system neither pressurizes nor depressurizes the air inside a home. The mechanical ventilation system allows full control over the equal flow of air indoors, instead of relying on natural ventilation as one normally would.

A balanced ventilation system usually has two fans and two ducts to exhaust air out and bring air in at the same time, in equal volumes.

Simple and basic balanced ventilation setups could include exhaust vents and fresh air supply in every room in the house.

But typically, the supply of fresh air is placed in bedrooms and living rooms, where occupants spend the majority of their time. Exhaust vents are placed in rooms where pollution and moisture are more often present. These places could include bathrooms, kitchens, and laundry rooms.

This basic setup does not affect the temperature of indoor air. Unfortunately, this system could allow heated or cooled air to either escape or make its way inside the building (depending on the season).

More complicated balanced ventilation setups like the HRV and ERV propose a solution to this.

HRV and ERV balanced ventilation systems

An HRV, Heat Recovery Ventilator, and an ERV, Energy Recovery Ventilator, are balanced ventilation systems.

What sets them apart is that instead of letting hot or cool air in and out of a building, they’re able to retain and exchange some of that heat energy from the outgoing air over to the incoming air.

This process, which happens in the heat exchanger of a unit’s core, then preheats or precools air. This also takes a huge chunk of the heating and cooling load on your home’s heater and air conditioning units.

HRVs retain and transfer only heat from the outgoing air to the incoming air.

ERVs, on the other hand, are capable of transferring not only heat energy but also moisture and humidity. This allows stable relative humidity levels indoors, preventing air that’s too dry or air that’s too humid.

If you want to learn more about HRVs and ERVs and how they’re both similar and different, head to our guide here.

Balanced vs Unbalanced Ventilation Systems

So we’ve talked a great deal about balanced ventilation systems. Let’s turn our attention to its counterpart – unbalanced ventilation systems.

Many mechanical ventilation systems are either exhaust-only or supply-only.

Exhaust-only ventilation systems exhaust and vent air out from inside the house but aren’t designed to draw fresh outdoor air in. When polluted air gets out but no air is pulled in to replace what was removed, this creates negative pressure in indoor air. As a result, the house will pull air in from any crack, gap, or opening in the house.

Supply-only ventilation systems are the total opposite. These ventilation systems only pull in outdoor air and are not capable of expelling used, stale indoor air. This creates a positive air pressure inside homes. This forces the indoor air to leak out anywhere there is a gap or crack.

Unbalanced ventilation systems can draw in a variety of pollutants and contaminants into your home or cause excessive indoor moisture, leading to condensation.

For equal volumes of air going in and out of a building, a balanced ventilation system is preferred.

Benefits of Balanced Ventilation For HVAC

Balanced ventilation system for your home’s HVAC system offers many benefits:

  • Exhausts polluted indoor air and draws in fresh outside air in an approximately equal amount.
  • Neither pressurizes nor depressurizes indoor air quality.
  • Controls pollutants and contaminants in indoor air.
  • Provides a continuous supply of fresh outdoor air while venting out the stale and polluted indoor air.
  • Provides improved and efficient indoor air quality which eventually translates to better health and comfort.
  • Gets rid of leaking cool and hot air which boosts the performance and efficiency of your HVAC system.
  • Different systems are appropriate and applicable to all climates and different building constructions.

Drawbacks of Balanced Ventilation For HVAC

It’s important to keep in mind that a balanced ventilation system for your HVAC system can also manifest some drawbacks:

  • It requires two fans and two air ducts so generally, its installation does not come at a cheap price. Operation costs may be higher than exhaust or supply-only ventilation systems.
  • It could require more maintenance than other ventilation systems.
  • A system that’s not an HRV or ERV does not tamper with indoor temperature and moisture levels.
  • It’s easy to compromise the performance and efficiency of the unit at the installation stage. This is why you would want a professional installer with enough experience and credibility under their belt to work with yours.

Balanced Ventilation System: Different Types and Designs

A balanced ventilation system can take on different types and designs, depending on what your home and family needs:

Single-Point System

The single-point system is a very simple and basic approach to balanced ventilation systems.

This system involves a single exhaust point and a single air supply point as well. The incoming air from outside is also filtered so there are no pollutants and contaminants making it inside your home.

This is the cheapest option you’ve got if that is what you are looking for. And it won’t fail you when it comes to simplified ventilation.

The downside to this is it doesn’t achieve whole-house ventilation. It will not ventilate stale indoor air and provide fresh outdoor air evenly throughout all rooms in the house.

For this reason, you would need to use local exhaust fans in rooms that need them like kitchens and bathrooms.

Multi-Point System

The multi-point system is a fully-ducted system and is the most efficient venting solution out there. Before we get into it, we must tell you that since this requires ductwork throughout the house, it’s also the most expensive system to install.

This has a multi-point duct system so it’s able to supply fresh air to the rooms in the house. It also exhausts polluted air from areas like the kitchen, bathroom, and laundry room.

However, there might still be the need to install local exhaust fans in bathrooms and kitchens if no central exhaust is located in them.

Multi-Point System with a Partial Connection to Central Air Handler

If your house has a central air handling system, this system is a great option for a moderate initial cost.

This multi-point system works to vent out the exhaust and stale indoor air from your home’s common living spaces.

At the same time, it supplies fresh outdoor air to the central handler’s supply trunk. The supply’s duct system then pushes this new supply of outside air (with a damper), to the rest of the rooms in the house.

This system requires fan cycling, a central air handler interlock, and a motorized damper to work.

This air handler fan system is especially important for homes located in a humid climate. This system has to run whenever your home’s HRV is on and operating to avoid creating condensation that can lead to mold.

Multi-Point System with Full Connection to Central Air Handler

Similar to the multi-point system with partial connection, this full connection system requires a a central handler interlock, fan cycling, and a damper that is motorized.

This works by exhausting air from the central air handler’s return trunk and at the same time drawing in fresh outdoor air through the supply trunk. The supply duct system then distributes this new air supply throughout the rest of the home.


Every home needs proper ventilation, after all, we spend most of our time indoors and mostly with our doors closed. Today’s modern homes’ construction plus daily activities could make indoor air stuffy and uncomfortable. Ventilation isn’t the only thing to consider, keeping a balanced ventilation is as well.

A balanced ventilation system is a mechanical ventilation system that neither pressurizes nor depressurizes indoor air, which helps to balance out the air coming in and coming out of your home.

You can get in touch with us below if you have more questions you would like answered!

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