How good is the air quality inside your home? You may want to consider a heat-recovery ventilation system, advises home inspector Sean Moss
What is an HRV System?
An HRV or “Heat Recovery Ventilator” is a mechanical air-exchange system that brings fresh outside air into the home, while heating and strategically distributing it throughout the house.
Fresh outside air is drawn into the home with one vent, while passing through a filter in the system. Meanwhile, the older, warm, stale air is pushed outside with another vent. The heat is exchanged, but the air is not recycled. So, essentially, this process recovers heat that would otherwise be lost.
HRVs are typically designed for newer well-insulated, tight buildings rather than drafty older homes. However, with the proper retrofits, they can be installed in any home.
Before I jump into the benefits of an HRV, it is important to understand ventilation, as it serves two main purposes:
- To provide the necessary oxygen for people to breathe.
- To remove, or at least dilute, contaminants from the home.
Poor indoor air quality has been documented to cause negative health effects on humans, especially the very young, elderly and people with sensitivities. Sufficient ventilation, combined with proper filtration, is necessary for the maintenance of proper indoor air quality.
Benefits of an HRV System
Our homes are filled with all kind of pollutants, dust mites, pet dander, odours and toxins. The HRV system effectively removes them from the home to improve our indoor air quality. This is especially beneficial for those who suffer from asthma or allergies.
Some systems can recover more than 80 per cent of the heat before it leaves the home, which is budget friendly, while reducing the need to open more windows.
We generate a lot of moisture in the home from plants, through washing, cooking bathing, laundry, and breathing. Condensation can also contribute to visible and hidden moisture. HRVs remove this moisture from the home, resulting in lower levels of humidity, mildew and mold, especially from high moisture areas such as bathrooms and kitchens.
The end result is a clean, fresh and more comfortable living environment.
Where to Install the HRV
The HRV system should be located in a space that is conditioned (heated), easily accessible with ample room for maintenance and in close proximity to an exterior wall – this is important as you will need a short duct run to the outside.
Avoid closets, as they can be result in noise issues. Attics are difficult to get to, often resulting in neglected maintenance, and garages should be avoided because they are cooler, thus reducing the efficiency of the system.
Ideally, your HRV system should be installed by a licensed, experienced ventilation contractor, as there are a number of important sizing calculations and requirements to ensure the system runs properly with optimum efficiency.
What about Maintenance?
The HRV system is intended to run 24/7, so annual preventative maintenance by an experienced, licensed contractor is required.
Have your contractor show you how to do some of the simple maintenance tasks, such as replacing the filter, cleaning the drain pan and checking the exterior intake/exhaust hoods. Unless you are properly trained, leave the complicated components to the professionals.
With increased exposure to and knowledge of indoor air quality, as well as moisture issues, the demand for HRV systems is becoming common practice.
For more information and specific details, including costs and pay back periods, contact a reputable HRV contractor to learn more.