Positive Input Ventilation System: Looking for fresh clean indoor air quality? Nuair Positive Input Ventilation range uses proven technology to cure condensation and improve your air quality. For as little as 5 cent per day to run, our positive input ventilation systems will ventilate your entire home. The Drimaster-Eco range is for homes with loft. The Flatmaster range is for homes without lofts. Condensation dampness is a common problem in airtight new build homes as well as poorly insulated older properties. Positive Input Ventilation (PIV) eradicates this problem by pushing fresh filtered air into the home at a continuous rate, this process removes condensation, allergens such as pollen and dust mites.