Here are some solutions to provide healthier indoor air quality in your homes.
1. Install a filter with a MERV rating of 13-16 (higher is better) for ducted heating/cooling systems. A HEPA level filter is even better that captures 96% of virus sized particles. This is a great solution for people with allergies or other sensitivities.
2. Seal all ducts with mastic, not tape. This is a requirement of the new Oregon code. This helps reduce leaks that lead to callbacks from air quality and comfort issues.
3. Install balanced ventilation. This is a requirement of the new Oregon code. The supply and exhaust must be within 10% of the same flow rate. You can achieve this in several ways but best is an HRV or ERV which is 1 piece of equipment that saves energy and increases comfort since they integrate heat recovery. While HRVs can cost more than non heat recovery systems, you can save money by eliminating bath fans and integrating the exhaust into the HRV.