This system uses low pressure steam to heat the gas stream and can be installed as a direct replacement of an existing WBH with the added benefit that only 1 system would be required to replace 2 existing WBHs due to the modular nature of the design.
The system is based on gas burners heating a water-glycol mix until it becomes steam. By creating a vacuum containing the system fluid, the steam is created at around 42°C, this is a significantly lower temperature steam produced from water at atmospheric pressure. Once this steam condenses on the cold gas stream pipe it gives off an enormous amount of energy compared with the energy potentially given up by a liquid at the same temperature. This then allows the system to contain considerably less fluid than it would if a liquid was the heat transfer medium resulting in reduced thermal losses.