Ventilation is necessary for a few reasons including:

• Airtight Homes

  - Homes designed and built in recent years are more airtight and energy efficient than in the past. To obtain this airtight design, house wraps, newly designed windows and doors, sealing caulks and other insulating materials are used to create a seal for optimum energy efficiency. The resulting benefit is fewer drafts, which lowers the cost to heat and air-condition a home. But pollutants retained in airtight buildings can be hazardous to their occupants and can jeopardize structural integrity. That's why Panasonic stresses a "build tight and ventilate right" platform. Proper mechanical ventilation design can address poor indoor air quality, while retaining energy efficiency.



• Biological Pollutants

  - Biological pollutants, to some degree, are found in all homes. These include mold, mildew, pollen, dust mites, pet dander, viruses and bacteria. Accumulation of these "biological pollutants" can result in hazardous health effects for the occupants, as well as structural damage to the building.



• Volatile Organic Compounds (VOCs)

  - Volatile Organic Compounds are carbon-based compounds that easily evaporate. These types of gases are released from building materials, carpets, furniture and many other solid household items as part of aging, decomposition or curing, all of which are natural processes known as "outgassing". Some other household items that emit "VOCs" include hair sprays, paints, lacquers, finishes, oven cleaners and other cleaning solvents, pesticides, etc. Often colorless and odorless, VOCs can ultimately sensitize certain people to react to them.



• Ways to improve indoor air quality

  - Unfortunately, indoor pollutants are virtually impossible to eliminate completely, creating the need for a second step to improve indoor air quality-mechanical ventilation. Mechanical ventilation is used to remove stale, moist, polluted air and replace it with fresh outside air. Two widely used methods in today's building industry are continuous and intermittent ventilation. Most industry experts agree that we should not rely on natural pressures and passive ventilation through vents, leaks or holes in the building envelope.