Humidex crawlspace ventilation system is a value-added solution for your customers that reduces moisture problems and poor indoor air quality. Provide a healthy, dry environment with an easily installed, standalone unit that is automatic, continuously operating, maintenance-free and saves energy. Offer a better solution than dehumidifiers that meets building codes. Increase customer satisfaction, referrals, lead opportunities and more revenue. Basement units also available. Now through Dec. 31, 2017, use promo code PMP 17 for 10 percent off plus free shipping.