Re ECF Project: 2009-11

Project Title: Sustainable low cost residential humidity control in Hong Kong

Applicant: Prof. DENG Shiming of The Hong Kong Polytechnic University

Total Approved Grant: $555,700

Duration: 1/5/2010 to 31/1/2012

Project Status/Remarks: Completed

The project aims to develop a novel low-cost residential humidity control technology which can contribute to sustainable development through energy saving and improved indoor thermal control; and to demonstrate the technology to relevant stakeholders.

Summary of the Findings/Outcomes:
Three parts of research work have been undertaken. In Part I, a questionnaire survey and field measurement on indoor thermal environment and the use of air conditioning in residences in Hong Kong were carried out. In Part II, a dynamic model that was used to better understand the operational performance of a DX A/C unit under the previously developed H-L control algorithms was developed. Finally, the H-L control algorithms was implemented through Dual-Single (D-S) control experimentally.

The survey and site measurement results revealed that most people surveyed preferred to stay in a cooler indoor environment by selecting a lower indoor air temperature setting. However, only in about a quarter of the 500 premises surveyed, the recommended indoor design conditions (23-25.5 °C and 50-60% RH) for summer air conditioning in Hong Kong were achieved, with also a quarter of the surveyed premises having a resulted indoor RH over 60%. On the other hand, extensive experiments have been conducted to validate the control performance of the D-S control. Experimental results suggested that the use of D-S control could result in a similar performance with the H-L control, but a lower initial cost.