Take breath of fresh air! Connect an HRV to your ductwork to remove the stale air from your home

“Simply” connect an HRV/ERV (Heat recovery ventilator / Energy or Enthalpy recovery ventilator) to your ducted heating system. When professionally designed to meet your needs, this device will reliably bring the required amounts of fresh air into the home by exchanging the stale air that is circulating in the house, through the ducts. The HRV/ERV will retain the heat while exhausting the stale air, and introduce fresh air from the outside.

Today, the Ontario building code requires all new mechanical construction applied for after January 1st, 2017, to incorporate an HRV for ventilation in the building envelope. With today's increased requirements on insulation levels and air tightness levels, It is important to maintain an even air exchange, meaning, the exhaustion of stale air should occur at the same rate as the intake of fresh air, since in air tight homes, expulsion of contaminants cannot be achieved naturally. For that reason, the government of Ontario mandated the ventilation using an HRV/ERV, as this type of equipment ventilates and exhausts at eve rates.

Benefits and risks of an air tight home

The following information may be inconvenient to take in, but in fact, by introducing a well designed ventilation system that efficiently exhausts stale air and toxins out of your building envelope, most of these health risks can be mitigated.

The following statistics are posted on the statistics Canada website for the time period of 2013-2015:

- 5% of households surveyed reported a sick family member due to poor indoor air quality.

- 7% of households surveyed reported having poor indoor air quality.

- 12% of households surveyed reported noticing mold and mildew growth.

The world health organization lists key facts on indoor air pollution and health:

- Household air pollution was responsible for an estimated 3.2 million deaths per year in 2020.

- Household air pollution exposure leads to noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer.

- The combined effects of ambient air pollution and household air pollution are associated with 6.7 million premature deaths annually.

You can find more inconvenient facts, not listed here, about indoor air pollution, on the world health organization's website.

Other than the function of heat recovery, an HRV/ERV’s significant function is the removal of stale air and toxic fumes from the circulating indoor environment, and the introduction of fresh outdoor air into the heating system, to mitigate the associated health risks within the indoor environment.

When “Simply” connected to the gas furnace or an air handler, the HRV/ERV’s exhaust pipe is attached to the return air side, about 3 feet away from the drop back to the blower and plenum; From there, the HRV/ERV exhaust pipe will draw the return air into the its heat exchanger, recycle the heat from the furnace air, remove the stale air and excess moisture, and introduce fresh outdoor air back into the system, allowing for the proper ventilation of the air that's circulating through your indoor environment.

Other ways to have an HRV/ERV operating in your home is to fully duct it and have all the exhausts in the home (Washrooms, Laundry, Mud room etc.) directly connect to it's ductwork. This configuration is an optimal one for the proper ventilation of a home, however, in cold climates, this is not a sufficient heating solution. A fully ducted HRV/ERV is recommended to be simply connected to a furnace at the intake side, to allow fresh outdoor air.

The differences between an HRV (Heat recovery ventilator) and an ERV (Energy or Enthalpy recovery ventilator) can cause significant consequences to the operation of the heating system and indoor air quality. In the heating months (late Fall, Winter, and early spring), we experience a drop in humidity, making the indoor environment drier, and while it is recommended to maintain humidity levels of 35-55% inside the home, the ERV could potentially draw excessive amounts of moisture from the indoor environment, making it drier, creating potential health risks, and exposing the equipment to freezing and jamming, due to moisture collecting in its pipes during the cold season. In cold climates, it is recommended to use HRV’s as the material of its cell is not permeable as it is in the ERV (for better moisture collection), and does not draw moisture.