ERVs circulate fresh air and moisture in the home while preventing heat loss.
HRVs circulate air but don't circulate moisture to draw humidity out of the home.
ERVs are better for hot, humid climates and save energy costs on running the AC.
HRVs have built-in defrost systems that make them ideal for colder climates.
If you've been researching ways to circulate air in your home and improve indoor air quality while maintaining a comfortable temperature and moisture level, you may have heard of energy recovery ventilators (ERV) and heat recovery systems (HRV). But what exactly are these air exchange systems, how do they work, and which one is right for you?
While ERV and HRV systems function similarly and have comparable benefits, they have some key differences that you should consider before making a purchase decision. This guide breaks down what these systems are, their pros and cons, and how to make the right choice for your home.
ERV Pros and Cons
An ERV system works with two fans—one pulls stale indoor air out of the home, and the other pushes fresh air into the home. It features a heat exchanger that draws the heat out of the stale outgoing air and transfers it into the fresh air coming in to prevent heat loss. Here are the pros and cons of this type of system.
ERV systems tend to have two chief benefits: they prevent heat loss and keep out air contaminants. However, ERV system manufacturers also claim that an ERV system will result in better HVAC performance (and a longer life for your HVAC system), and it will lower humidity in your home.
One of the main cons of an ERV system is that it may not save you on heating and cooling costs because it uses electricity. If you live in a milder climate where you don’t run an HVAC system that much, an ERV system may cost more than they save. Also, ERV systems can be noisy, so be careful not to install them right next to the windows in living spaces. Finally, an ERV system may cost thousands of dollars to install.
HRV Pros and Cons
While HRV systems function similarly to an ERV, it has one key difference: an HRV system only transfers heat, while an ERV transfers both heat and moisture. Here are the pros and cons for an HRV system.
For those who live in cold climates, the fact that an HRV system doesn't lower humidity as much as an ERV system is a pro because air is drier during colder months. As a result, an ERV system may make the home too dry, requiring you to run a humidifier as well. Other than that, an HRV system's benefits are similar to that of an ERV: it prevents energy loss while ensuring a constant flow of outdoor air into your home.
While the fact that an HRV system doesn't transfer out as much humidity may be a benefit, it may be a con if you live in a hot and humid climate. An HRV system may not keep your home as comfortable in these areas because it doesn't keep out as much humidity. Also, an HRV system can keep your home warm but cannot keep it cool, so it may be best to simply disable it during the warmer months to save on energy costs.
ERV vs. HRV
So which system should you choose? The most important factor to consider is the type of climate you live in. While both ERV and HRV systems do a good job of reducing the overall stress on your HVAC system, they will perform differently depending on what kind of temperatures and humidity levels you experience throughout the year. A local HVAC technician can help you decide which system is the best for your climate.
Functionality in Cold Climates
ERV systems don't function as well in colder climates because an ERV cell can freeze up more easily when temperatures drop to a certain level. In these cases, ice will form within the ERV cell, resulting in a reduction in airflow. HRVs, on the other hand, have built-in defrost systems to prevent the cells from freezing up.
Best in freezing temperatures: HRV
Functionality in Hot, Humid Climates
However, an ERV system may be the better option if you live in hot, humid climates. That's because an ERV system does a better job of reducing humidity in the home. It also helps the air conditioning unit run less than if you have an HRV system, keeping your home more comfortable while expending less energy.