The primary goal of this study is to investigate the comparative long-term (i.e., 1-year) effectiveness of energy recovery ventilators (ERVs) and portable air cleaners (PACs) in reducing indoor air pollutants and mold levels and improving asthma-related health outcomes in inner-city children and adults with asthma in low-income households in the Dallas-Fort Worth (DFW) metropolitan area, TX. Secondary goals include: (1) examining associations among asthma outcomes, exposure to indoor air pollutants and mold, and housing-related factors, (2) conducting a cost-benefit analysis of ERV and PAC interventions for improving IAQ, mold control, and health outcomes, and (3) evaluating the utility of cost-effective methods and protocols for measuring IAQ and mold for indoor air pollution epidemiology studies and for providing practical information to patients and their physicians. Using a double-blind, placebo-controlled randomized controlled trial, 80 households will be assigned to receive active or placebo versions of ERVs or PACs. Environmental exposures and housing conditions will be monitored alongside comprehensive health assessments, including lung function tests and validated surveys on asthma control, quality of life, stress, and sleep quality.