Ventilation systems transfer polluted indoor air to clean outdoor air. They need to be sized for a specific climate, otherwise they may exhaust moisture-laden air into cold homes or cause mold and corrosion in attics and exterior walls.
There are many different types of mechanical home ventilation systems to choose from. A quality system can help make your home healthier and more comfortable, while also saving energy.
Increased Comfort
Modern home ventilation systems provide an ongoing supply of clean air, regulating temperature and humidity and reducing condensation. Ventilation removes unpleasant odours, dust, pollen, carbon monoxide and contaminants from indoor air, making it safer to live in.
During the winter, humidity and condensation are a big problem in houses. They can cause moisture damage, mould and wood rot. A good ventilation system allows the air to move throughout a room, keeping the moisture levels low and eliminating uncomfortable cold spots.
Air in a building is constantly used up, and ventilation systems recycle that air so the same amount of fresh air keeps coming in as it is going out. This is called positive pressure. A ventilation system can also be negative pressure, removing the old, stale air from a house and replacing it with new, outside air. This is called depressurization and works well in regions with cold climates.
The most effective ventilation systems combine positive and negative pressures to create an airflow that brings in and replaces the same amount of air as it expels, ensuring an even exchange of indoor and outdoor air and preventing energy waste and temperature fluctuations. There are four major types of mechanical whole-house ventilation systems – exhaust, supply, balanced, and heat-recovery. Each ventilation system should be designed for the climate in which it will operate.
Reduced Humidity
Some moisture in the air is good, but too much makes it feel sticky and irritates skin. Ventilation systems can dehumidify the air to make it more comfortable and prevent mold growth and musty odors.
Keeping stale indoor air out and fresh outdoor air in is key to reducing humidity levels. Ventilation can include opening windows and doors, using exhaust fans in moisture-prone areas like bathrooms and kitchens, and whole-house ventilation systems such as ERVs and HRVs.
Properly installed and maintained ventilation systems reduce humidity by allowing contaminated air to escape. They also provide an easy way to recycle filtered outdoor air throughout the home.
Adding extra ventilation to a well-insulated home can minimize humidity problems and avoid high energy costs by allowing conditioned outdoor air to circulate freely through the house. Ensure that appliance venting systems are properly installed and free of blockages to allow moist indoor air to be exhausted and limit condensation on surfaces.
Reduced Risk of Asthma
Home ventilation systems that dehumidify the air may make it easier for asthma sufferers to breathe at night, a small study suggests. Lower indoor humidity should reduce concentrations of moisture-loving dust mites, a major trigger of breathing difficulties in many asthma sufferers. Researchers in Glasgow fitted ventilators to the homes of 119 people with asthma, then measured their evening breathability. Those in ventilated homes showed a significant improvement over participants without ventilators, Reuters Health reports.
The researchers believe the improved ventilation helped to dehumidify the homes, reducing the number of moisture-loving dust mites in bedrooms and bedding. The ventilators also brought fresh outdoor air into the houses, lowering indoor pollution levels. They used a passive ventilation control system that relies on the “stack effect” to automatically move hot air from the bottom of the building up through vents, chimneys or openings in the roof.
While the findings of the study are promising, further research is needed to confirm the link between ventilation rates and asthma symptoms. Until then, it’s essential to install a ventilation system that works well for your climate. Ventilation systems that don’t match the climate of a region will do more work than necessary, increasing energy costs and consuming more resources. A professional home ventilation system will use sensors to monitor your climate, so the system only operates when it is needed.
Reduced Risk of Carbon Monoxide
Carbon monoxide poisoning can be deadly at high levels, and even low levels of exposure cause visual impairment, impaired work capacity, and difficulty learning. Ventilation systems can prevent this odorless, tasteless gas from entering the home. This is especially important because carbon monoxide is produced by furnaces, stoves, portable camping stoves, charcoal grills and gasoline-powered engines. Often these sources are located in semi-enclosed areas such as garages and porches where CO can build up.
Mechanical ventilation systems can be designed to strategically locate intakes and exhaust points to reduce the spread of pollutants from one area to another. For example, intakes can be placed away from the sides of the house to avoid odours and pollutants from neighbouring homes or businesses migrating into indoor spaces. Exhaust points can be strategically placed to avoid moisture-laden air being exhausted into interiors where it can damage walls and ceilings, and odours and pollutants from inside the building being vented outdoors where they could be breathed in by family members or customers.
A good ventilation system also helps to reduce the accumulation of odours, odour-producing gases and volatile organic compounds in a home or building. This can be achieved by using high-efficiency air filters that use less media surface and design airflow patterns that minimize ductwork. Alternatively, chemically-treated adsorbent and activated carbon filters are available to remove odours and VOCs from the ventilation air in some applications.