Is partial application still effective? 

Yes, it exerts its effects on the surfaces of applied areas. Applying it to high-touch points frequently handled by multiple people—such as doorknobs, handrails, and switches—helps reduce the risk of contact infection. Additionally, applying it over a broader area such as walls and ceilings increases the opportunity for indoor air circulation to bring odor sources, airborne allergens, VOCs (volatile organic compounds), and mold into contact with the treated surface, enhancing overall spatial purification.