Yes, HVAC systems can cause respiratory problems. Poorly maintained HVAC systems can lead to the accumulation of dust, mold, and other allergens in the air, which can cause respiratory irritation and even serious illnesses. Additionally, HVAC systems can also spread airborne viruses and bacteria, which can cause respiratory infections. To prevent these issues, it is important to regularly maintain HVAC systems and replace air filters as needed. Additionally, it is important to ensure that the air ducts are properly sealed and insulated to prevent the spread of allergens and bacteria.