Abstract
Many New Zealand residential dwellings suffer from dampness and fungi during the winter, which can cause respiratory health problems. This can be due to poor insulation and ventilation, and the situation worsens when residents cannot afford to heat the dwelling. The main aim of this paper is to modify an existing dehumidifier so that it can remove moisture, heat the living space and reduce fungi growth and bacteria. To achieve that, we installed ultraviolet germicidal lights (UVGI) in an existing dehumidifier with a total cost of USD $150.7 (NZD $213.76). The UVGI lights are known to be efficient in destroying the DNA of fungi and bacteria. The results show that the device reduced the fungi growth and did increase the room temperature because the dehumidifier captured two litres of water over 24 h of testing. The proposed device did achieve a reduction in particulate matters, from 0.9 μg/m3 to 0.14 μg/m3 and an acceptable range of relative humidity below 50%, which reduces the favourable conditions for fungi growth. Therefore, our proposed low-cost device does improve the indoor air quality (IAQ) in the living space.