The air in a tightly sealed home can be up to 10 times more polluted than outdoor air. While a tight building envelope is important for energy conservation, ventilation is very important for filtering out the polluted air and infusing the home with fresh, unpolluted air. Unfortunately, systems that rely on exhaust-only or supply-only ventilation can throw off the pressure in a home and have limited ability to filter the air. A balanced ventilation system is much better at filtering pollutants out of the air and maintaining pressure.
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