Should You Go with a Heat Recovery Ventilation System?

Heat recovery ventilation or HRV systems are a staple of energy-efficient home design. The HRV system removes stale air from the home while transferring heat to the incoming air. HRV technology is very similar to the closely related energy recovery ventilator, though it does not transfer water vapor like an ERV. Should you go with a heat recovery ventilation system? We’ll outline the pros and cons of the technology. We’ll also list factors that help you determine if heat recovery ventilation is right for your home.

 

The Benefits of HRV Systems

HRV systems typically result in a greater exchange of air in your home. This helps remove excess humidity, indoor pollutants, and allergens inside the home. The HRV system comes with air filters that clean the air being pulled inside, while any allergens, dust, and germs in extracted air are prevented from mixing with the incoming air. This dramatically improves the indoor air quality of homes with HRV.

The HRV system transfers heat from the outgoing air to the indoor air, and it does this almost passively. The heat exchanger in the HRV can capture anywhere from 70 to 95 percent of the heat. This dramatically reduces heating costs in a cold climate. You no longer have to choose between being warm or feeling stuffy. This can reduce the amount of energy required to keep your home comfortable by up to a third.

HRV systems are much quieter than the conventional fans used to move air through our homes. And they need relatively maintenance. The only thing most homeowners need to worry about is changing the air filters.

You can control the rate of air exchange, just as you can adjust the temperature on your thermostat. You can reduce the rate of air exchange to lower your energy bill or increase it to remove bad smells.

The Disadvantages of HRV Systems

An HRV system tends to even out temperatures in your home. If you want one room to be much warmer than the others, you might have an issue. However, HRV, unlike ERV, does not transfer water vapor between incoming and outgoing air, so it won’t moderate humidity levels. For example, you may have to add bath fans to supplement the HRV when you take long, hot showers and leave a dehumidifier running in the basement.

HRV systems balance the temperature between incoming and outgoing air. While this reduces heating and cooling requirements, there are few places where it entirely eliminates the need for HVAC equipment. In cold climates, you’ll need a central heating system. Nor does HRV eliminate the need for air conditioning in the summer, though it can dramatically reduce it. And on a hot, humid day, your air conditioner will do a better job of cooling as well as dehumidifying your home or office.

Factors that Limit HRV Systems

HRV systems are a hallmark of ultra-efficient homes. These homes by definition have a very tight seal. Other homes have minor leaks of air through cracks and openings. Older homes with a lot of air leakage are not candidates for HRV because these leaks undermine the performance of the system. You’ll also hurt its efficiency if you regularly open your windows or leave doors open.

The performance of the system depends on the quality of the manufacturer and the installation. Suppliers like BPC Ventilation offer a wide variety of units. You could pick one that fits in your current home and comes with the advanced features you want. For example, they offer single room HRV units that are perfect for a bathroom or a sunroom that doesn’t have ventilation, in addition to whole house HRV systems.

Proper HRV system installations have ventilation/exhaust fans in rooms like the kitchen, bathroom, and utility room. You may want additional exhaust points where there are strong odours, whether this is the living room your pets prefer to sleep in or the bedroom where you choose to smoke in the evening. The ductwork necessary may be a problem in an older home if you can’t fit the ducts into the attic or between floors. This is why an HRV is an ideal choice when you’re building a new, energy-efficient home.

The exhaust point in the kitchen must be at least six feet (two meters) from the cooking surface. And it rarely entirely eliminates the need for a range hood. Not everyone wants multiple vents in the kitchen. You might be able to use the range hood in recirculation mode along with the HRV, but you want to retain the ability to quickly eliminate the smell of a burned meal if you already have it.

Maintenance Tips

If you decide to go for an HRV unit, you have to learn how to maintain it properly so you can get optimal performance and extend its lifespan. The most important thing is to always make sure that your filters are clean. You have to make sure that you replace or clean your filters every two months. Fortunately, this is something that virtually anyone can do and it can be done in minutes.

You’ll then need to make sure that exhaust hoods and your outdoor intake are clean at all times and free of debris. If your unit has a condensate drain, which is a piece of tube or a pipe coming out of the bottom of the unit, you’ll have to check it as well. All you have to do is drip about two litres of clean, warm water in the drain pans and see if there’s any backup. If there is, you need to clear the drain.

Other things you’ll have to look out for is the heat exchange core, ductwork, and grilles, and make sure that you have the fans serviced regularly as per the manufacturer’s instructions.

Conclusion

Heat recovery ventilation dramatically reduces HVAC costs while improving the comfort of your home. The technology is ideal for passively heated and cooled homes, but it can be implemented in an existing building.