In warm and humid climates such as Singapore, air conditioning systems are installed in most buildings for moisture removal from the air and lowering air temperature. This method is energy inefficient as significant amount of energy is required to remove latent heat from the moist air. Furthermore, the cooled and dehumidified air may need to be reheated to the suitable temperature level before it is used especially in specific applications such as cleanrooms.
The technology described herein combines membrane filtration and desiccant adsorption mechanisms to achieve the objective of moisture removal at lower energy consumption. Hence, dehumidified air can be directly cooled to the desired temperature.The membrane, comprising thin layers of nano-wires construct, is permeable to moisture but not to air. It enables removal of water selectively and efficiently (at high flux). In addition, the membrane can also be combined with photocatalytic materials to provide disinfection functions. The hybrid mechanism, combining the dehumidification capabilities of both technologies, improves air dehumidification efficiency by up to 85% when compared with silica gel desiccant approach.
The technology which combines both water vapour permeable membrane and desiccant technologies for air dehumidification in air-conditioning application consists of the following technical specifications:
- Water vapour permeable membrane made of ceramic membranes fabricated on a porous substrate. The ceramic membrane can be further incorporated with photocatalytic functions.
- Composite desiccant is designed with high dehumidification capacity compared to dominant silica gel while having characteristic of low temperature regeneration and reduced pressure drop
- The membrane is installed in a cross flow configuration with its surface parallel to the supply air flow and the composite desiccant surface is placed perpendicular to the supply air flow
- The hybrid achieves a larger dehumidification capacity with prolonged use as the membrane assists the composite desiccant in the extraction of moisture from the supply air stream. This also prolongs the continuous usage time of the desiccant before it requires regeneration.
In combination, the technology features above can be combined to provide a heathy indoor environment in an energy efficient manner.
Energy Efficient Dehumidification Solutions for HVAC application
Market Trends Opportunities
According to a recent market research report released by Transparency Market Research (Dehumidifier Market – Global Industry Analysis, Size, Share, Growth, Trends and Forecast, 2014 – 2020), the global dehumidifier market is expected to be valued at US$2.97 billion by 2020. The size of the dehumidifier market worldwide was worth US$1.93 billion in 2013. Increased adoption of dehumidifiers in commercial and industrial sectors is expected to boost the overall market in the near future. The report points out that various environmental regulations will push the demand for dehumidifiers in various industries. Dehumidifiers find critical application in pump rooms, platform legs, life boats, pipe tunnels, thruster rooms, and painting and preservation industries to remove moisture and decrease humidity in the air. Dehumidifiers are being integrated with existing HVAC equipment. Increasing usage of membrane technology in the dehumidification process has also been observed recently. The report points out that in 2013, desiccant dehumidifiers were the largest product segment in the market due to increasing demand from office buildings, restaurants, medical centers, and the food and beverages industry.
- Significant energy savings for chiller plant systems installed in buildings to achieve thermal comfort levels
- Enable better ambient environment control in builings as air humidity and temperature can be controlled separately
- The different technology features described can be used in combination or separately for retrofitting of air conditioning systems to achieve energy efficiency for different market needs