A ventilation system in your home can offer multiple benefits. For instance, it keeps the air inside fresh, reduces pollutants and allergens, and helps retain humidity while at the same time preventing excessive moisture from entering.
The two most popular choices for ventilation systems are heat recovery ventilation (HRV) and energy recovery ventilation (ERV) systems.
An HRV eliminates stale air from rooms with higher humidity levels, like the bathrooms or the laundry room. Simultaneously, it supplies fresh air to spaces where individuals often congregate, such as living areas or bedrooms. During summer, air entering is cooled, whereas air entering the room during winter is heated.
ERVs are pretty similar to HRVs in terms of how they function. However, an ERV allows some of the air’s moisture to stay in the house. To retain moisture, an ERV generally pulls in outdoor air during the summer and keeps some humidity in the air indoors during the colder months.
This article will explore the benefits and drawbacks of both systems and explore how you can decide which one is right for you.
What Is an HRV?
An HRV system consists of two air ducts—one carrying fresh air inside and one that brings exhausted air outside. Both outgoing and incoming air pass through a heat exchanger, which is a device that transfers heat between airstreams without letting the two come in contact with each other.
Depending on the humidity levels and temperature during a specific time of the year, the speed of the fan in both ducts can be adjusted. This way, the air supplied to the house is more efficiently cooled or heated.
Advantages of HRVs
Before we move ahead, let’s look at the benefits of an HRV.
Fresh Air in Your Home
HRVs can eliminate stuffy air from rooms with limited airflows, such as laundry rooms, bathrooms, and basements. They even supply fresh air into frequently used rooms like living rooms and bathrooms to enhance comfort.
On a hot summer day, you can use an HRV to precool the fresh air entering your house through your AC system. During winter, HRVs can recover heat energy through the heat exchanger to preheat the fresh air and can help reduce heating costs.
Reduced Carbon Footprint
Because of their incredibly efficient design, HRVs can minimize the carbon footprint produced by your house.
In the process of expelling stale air and bringing in fresh air from outside, nearly 85 percent of old heat is retained.
Moreover, HRV systems also minimize carbon dioxide levels, which is good for the environment as a whole.
Less Energy Consumption
Unlike air conditioners or boilers, HRVs are considerably more energy-efficient. So even though the fans run constantly, they consume very little energy.
A regular HRV unit consumes merely 13 watts of electricity, almost the same as a single compact fluorescent light bulb. As a result, you can potentially save around 30 percent on heating energy bills with an HRV.
Improved Air Quality
Contemporary houses are designed to be airtight to retain heat during winter and stay cool during summer. As a result, they need a moisture control system to stop the buildup of mold, mildew, pollen, and other contaminants—HRVs work 24/7 to eliminate moist air and replace it with fresh, clean air from outside.
Drawbacks of HRVs
Now, let’s weigh the cons of HRVs to help you make an informed decision before investing in one.
If your house is recently built and the HRV was installed initially, the price won’t impact you. But if you need to install it in an existing house, you’ll have to spend some money.
Installing an HRV in your home can cost anywhere between $1,150 to $2,250 for both the unit and installation.
If you live in a particularly old house, you might need to pay additional fines and fees, which can make the installation a little complicated, especially if you want to install it during summer.
Another possible drawback is that HRV systems do need some space. However, an installation professional can help you determine an appropriate solution.
In several cases, they may be installed in the home’s attic, meaning they will most likely be occupying space that would otherwise be vacant and could be used for something else.
No Improvements in Humidity
HRVs are great for people who wish to keep their insulated houses super snuggly. Nevertheless, while they do remarkable things for heating bills and heat, they don’t do much for your house’s humidity levels. This can be quite a significant issue, particularly if you live in an extremely humid region.
What Is An ERV?
As mentioned earlier, ERV systems work pretty similar to HRVs. One air duct pushes stagnant air out of your house, whereas the other draws fresh air inside. However, ERVs also help manage humidity.
An ERV can retain or eliminate humidity in your house by transferring moisture from one airstream to the other. The unit’s humidity control function improves comfort and keeps the core of the heat exchanger warmer, allowing it to operate more efficiently.
*Note, some of the links and pictures will take you to popular and some of the most affordable ERV’s we can find. We may make a small commission to support the blog if and when you purchase!
The image above is a link to the Panasonic FV-04VE1. We chose this one because it’s one of the most popular and most affordable ERV’s out there, if your home could use one. Designed for 4″ ducts, it’s Energy Star certified, is very quiet, and can install easy in the ceiling of your house.
Advantages of ERVs
An ERV system can minimize humidity in your house in the warmer months, keeping the air fresh and mold at bay.
During winter, ERVs let the air inside your home retain some moisture, which helps prevent nosebleeds and dry skin that can happen if the air is extremely dry.
Insects and other contaminants might be filtered by the ERV before reaching your home’s interior and your lungs.
Disadvantages of ERV
Now let’s talk about the points a sales team won’t tell you.
ERVs are high maintenance, and there are several things you need to do. For instance, you will have to vacuum the core and clean the filters.
ERVs are costly to purchase, install, and operate. In fact, the installation can cost more than the ERV itself. A whole-home ERV system can cost anywhere from $1,000 to $4,500+ with installation.
Shared Characteristics of HRVs and ERVs
First, let’s look at what the two ventilation systems have in common. Both HRV and ERV reclaim energy from air exhausted from a home.
This energy is then added to an incoming current of fresh air to either precool or preheat it. In short, ERV/HRVs take the air from inside your house and circulate it with air from outside your home, allowing heat to move between them.
Before reaching the rooms, the air that enters your home is either warmed or cooled (depending on the season). This way, you can enjoy fresh air in your home without exerting pressure on the air conditioner or heater.
HRVs and ERVs have gained popularity in recent years as houses do not “breathe” as well as they once did. Homes now have more robust insulation to cease heat gain and heat loss.
While this increases the energy efficiency, it can make it stuffy and introduce contaminants. Installing an ERV or HRV allows your house to breathe without experiencing a dip in energy efficiency.
Differences Between HRVs and ERVs
One significant difference is moisture recovery. HRV systems only recover cooled or heated air (depending on the season), whereas ERV systems recover both relative humidity and heat.
In colder months, moisture recovery prevents your indoor air from getting too dry, whereas, during the hotter months, it stops excessive humidity from entering your house.
Dry air can make your family more susceptible to health conditions such as sore throats and dry skin. Conversely, too humid air promotes mildew and mold growth, resulting in respiratory problems and allergies. Both these extremes can deteriorate your home’s structure.
HRV vs. ERV: Which One Is Better for You?
There are multiple factors to consider when deciding which ventilation system is suitable for you, including:
The Climate of Your Region
If you reside in a region where the winter season is long and dry, an ERV might be better for you. As the ERV retains a certain amount of humid air in the house, it may reduce dryness issues like static electricity and dry skin.
Nevertheless, an ERV isn’t just suitable for regions that experience a dry winter. It might be the right choice for areas with hot and humid summers.
On the surface level, an HRV might be the right choice for such climates as it gets rid of excess humidity in the air. It might sound unreasonable to install a ventilation system that lets humidity stay in the house, particularly if yours struggles with moisture.
However, an ERV can effectively minimize the humidity level in your house better than an HRV during summer. It can even cut down your energy use as it requires you to run the air conditioner less than if it were working against a higher percentage of moisture output from the HRV.
Homeowners who want to reduce the air’s humidity can benefit from switching on their dehumidifier alongside the ventilation system.
The Number of People in Your Home
Your family and home’s size is another factor you need to consider when selecting your ventilation system. The more people in a house, the more humidity will arise from cooking, showers, or just breathing. In such a household, an HRV will be a suitable choice.
On the other hand, ERVs are perfect for larger houses and smaller families.
Your Existing Heating System
HRVs work well when using a non-drying heating system like a boiler. If your heating system dries the air (for instance, electric baseboard heaters), an ERV is more suitable.
Your Home’s Age
ERVs are better tailored for homes built before the 1970s with drier indoor air because their construction allows humidity to escape outdoors. HRVs are recommended for newer, more airtight houses.
Sealing of the Building
The better the windows and walls are sealed, the more moisture remains. Therefore, opting for an HRV makes more sense.
If you or your family members have asthma, allergies, or a skin condition, dry air can aggravate these symptoms. An ERV might be the best choice for your family in such cases.
There’s no one right choice between HRV and ERV systems. It all depends on your region’s climate, family and home size, and overall lifestyle.
In an ideal world, we would have one of each system or maybe an integrated system that monitors and adjusts indoor air quality automatically so that we won’t have to make a choice ourselves.
One thing that’s for sure is that whichever system you pick, an airtight home equipped with an HRV or ERV is an evolutionary jump beyond the 20th century’s leaky dwellings.