United States.
A team of scientists from the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) and the University of Florida (UF) has developed a new method that could produce low-cost, high-efficiency systems for water heating in residential buildings.
The theory behind the newly called "semi-open" natural gas design is that it reduces the cost and complexity of traditional closed gas systems by streamlining, and even eliminating, certain components. When applied, the new concept could result in something better than 100% energy efficiency, as the system draws energy from the surrounding air as well as natural gas.
The design combines the functions of water heating and dehumidification, which are typically found in separate architectures. In the semi-open scenario, the absorbing device acts in place of the traditional evaporator component, pulling water vapor directly from the air through a membrane within a liquid solution. As the steam is absorbed, much of the heat is transferred to domestic hot water.
The simple semi-open system would operate at surrounding atmospheric pressure, using a low-cost, unsealed solution pump. This approach eliminates the need for vacuum pumps found in closed systems that purge accumulated gas. It also allows manufacturers to consider lower-cost and lightweight polymers, rather than expensive bulky metals to build equipment, making it less susceptible to corrosion.
