As more multi-residential buildings are made to be energy efficient, they are also affecting the quality of the air we breathe. Designed to keep heat and cool air in, airtight buildings contribute to lower energy bills, but they also keep the fresh air out.

This is where air ventilation plays an important role. Much like a set of healthy lungs, the goal of ventilation is to keep the clean, fresh air inside while moving the bad air outside. Without that air exchange, moisture can breed mould and mildew, allowing dust mites to flourish, which can lead to a greater risk of health issues in building occupants.

Depending on various factors and rates of exposure, indoor biological pollutants, such as VOCs, CO2, moulds, and other allergens, can cause serious health issues to manifest. Some of these biological pollutants have been linked to the onset of asthma, headaches and concentration problems. Furthermore, healthy indoor air quality will allow occupants to breathe better and sleep sounder.

Presently, there is no recommended response for multi-residential building owners in terms of building ventilation as it relates to COVID-19. However, it is important that building systems are functioning as intended to prevent potential ventilation problems that could worsen airborne transmission.

To better understand how we can create healthier homes for current times and into the future, we first need to understand the three types of ventilation systems that can be used, either separately or together. Each system has its own unique benefits that contribute to achieving healthy indoor air quality.

Natural ventilation

Natural ventilation, as the name implies, is the natural movement of air currents that flow through a home uninfluenced by human technology. Wind ventilation, for instance, is achieved by opening windows and doors to allow unfiltered air to circulate through the rooms of a home. This type of ventilation can also occur through a process called infiltration, where fresh air sneaks in through leaks and cracks in the building itself.

The trend towards airtight construction for newer buildings has all but eliminated this source of ventilation. Furthermore, in multi-residential apartment and condo buildings, natural ventilation may not always be possible due to the unit layout. Buildings today that rely solely on natural ventilation may be limiting air exchange to instances in which windows are open.

Spot ventilation

A spot ventilation system uses technology to provide ventilation to very specific regions of the home. Most often, these systems are located in basements, attics, and other moisture-prone areas. In multi-residential apartment buildings, spot ventilation is most likely to be found in the form of exhaust fans in kitchens and bathrooms, as they quickly remove polluted air from their isolated location.

Individual room fans are another example of spot ventilation commonly found in multi-residential apartment buildings, and they come in a variety of configurations. Portable models can be placed on the floor or on a table, and mountable units can be permanently installed on a wall or ceiling to circulate the air in a particular spot or room. Spot ventilation, while effective, is rarely the sole form of ventilation in a dwelling and is best used as a supplement to additional ventilation systems that will filter the air.

Whole-home ventilation

Whole-home ventilation systems are the most common form of ventilation found in modern housing. These systems use a series of exhaust ducts and vents located throughout the dwelling to provide man-made, deliberate ventilation and circulated air flow. Boasting the ability to be managed, controlled, and modified entirely by the homeowner, building manager, tenant, or a licensed contractor, these whole-home ventilation systems include exhaust, supply, balanced, Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV).

In recent years, HRVs and ERVs have become more popular, especially in new builds and renovated properties, allowing for proper ventilation without sacrificing efficiency. HRVs recover heat as they ventilate the air. Their primary purpose is to save energy through tempering the air being returned back into the home by using the heat extracted from the air that is exhausted.

Ideal for some dwellings, an HRV system does not recover energy in the cooling season, and also extracts but does not recover moisture, therefore drying the air and requiring a humidifier to replace the lost moisture in addition to a condensate drain, and in some cases, a condensate pump. Because of this, HRV systems are often not the best option for multi-residential buildings, which would benefit more from an ERV solution. ERVs recover both heat and cooling energy, tempering with heat in the winter and cold in the summer while also capturing moisture and helping to maintain comfortable relative humidity in the units. ERVs are a year-round stand-alone solution and comfort enhancer ideal for MURBs. With proper ventilation in and out of the home, you can expect the indoor air quality to improve and residents will be able to breathe and feel better.

ERVs and HRVs can also be uniquely beneficial to the geography of the dwelling. For example, some systems are specially engineered for use in cold climate zones, providing a tempered air supply, humidity control, and a balanced amount of exhaust to help maintain balanced, positive or negative pressure throughout the home.

The importance of indoor air quality on overall wellbeing can’t be underscored enough. The quality of the air inside our homes often gets overlooked – you can’t see the problem so why look into a solution? However, the benefits of ensuring a home has the best indoor air quality can vastly improve the health of the inhabitants and stop potential side-affects associated with poor air quality. With technological advancements in the ventilation space, we’re able to change the standard of indoor air quality for future generations to build healthy home environments regardless of budget or dwelling type.

Kevin Smith is the general manager of Panasonic Canada’s Life & Device Solutions Division. For more information, visit: https://na.panasonic.com/ca/home-building-solutions/ventilation-indoor-air-quality/.