Complete 2 system furnace repair and preventative maintenance check. Changed filters. Dusted out furnace cabinets. Tested mechanical and electrical components. Found dirty blower wheels and worn igniters in both systems. Found main level flame safety sensor to be weak. Recommend repairs and blower wheel cleaning. Tested indoor air quality and found an average of 450,000 particles per square inch. Recommend breathe easy system. Replaced ignitors in both systems, replaced main level flame safety sensor and cleaned both blower wheels. Installed breathe easy bronze package in main level system. Systems are heating at this time.