A- In some instances better filters and UV lighting have helped some home owners and improved their air quality. However, in a lot of cases expensive filter and UV lights have done little to improve the home’s indoor air quality. In cases where no improvement was noticed other underlying problems were not considered. Equipment sizing and application, duct leakage, pressure imbalances as well as air handler and ductwork contamination were found to be the source of the problems. Therefore we recommend diagnostic testing prior to any prescription for action. Diagnostic testing in the form of air sampling, blower door testing , duct work performance analysis as well as inspection of the interior of the ductwork should be considered and or performed before considering which path of remediation to take.