Water-filled glass (WFG) as a Heat Displacement System for saving energy in buildings

The energy consumption of buildings plays a major role in global warming. Within this, window systems possess a significant responsibility for both reducing energy demand and improving thermal comfort. Here, the Water-Filled Glass (WFG) system has been proven to be an effective solution, that can substantially improve the energy performance of a building envelope. The ability of the system to absorb radiation and distribute heat throughout the building is a significant advantage; both cooling and heating demand is lowered, resulting in substantial energy savings and equivalent CO2 emission reduction.

In this paper, a prototypical office floor consisting of four rooms with fully glazing facades facing cardinal directions was simulated using TRNSYS in two climate locations: New York and London. Through a heat displacement approach, the model redistributes the solar gain absorbed in the South and West facing WFG windows, and transfers this to the heating-demanding rooms (shaded North and East facing windows).

The preliminary results show the potential of the WFG system to not only act as an effective isolated window unit, but also synergise with other window units via heat displacement to reduce overall building energy consumption: energy savings of up to 10.62% were recorded for the WFG office rooms in New York.