The development and experimental performance evaluation on a novel household variable refrigerant flow based temperature humidity independently controlled radiant air conditioning system

The present temperature humidity independent control (THIC) air conditioning (A/C) systems are not that applicable in small-to-medium scaled residential and office buildings for their complex configuration and additional requirement of regenerating heat. In this paper, a novel house-hold VRF based radiant A/C system adopting outdoor air dehumidifier (OAD) was developed and experimentally tested. This novel system employed the VRF system, applying one refrigerant cycle to the OAD to cooling and dehumidifying the outdoor air and another to the Refrigerant-Water plate heat exchanger (RWPHE) to providing chilled water for the adopted radiant terminals. Therefore, the supplying outdoor air from the OAD handled the indoor latent cooling load and the radiant terminals the indoor sensible load, so as to realize the independent control of indoor air temperature and humidity. Experiments were carried out at different outdoor air states for examining the performance of this novel THIC system. The experimental results showed that the supply air temperatures were controlled at proper levels with a moderate fluctuation below 2 °C and the supply air humidity ratios were within 8-10 g/kg, meeting the requirement of ASHRAE's recommendation. Therefore, the results suggested promising performance of the developed system in temperature and humidity control.