Beneficial Un-Mixing
Low loss headers, such as those used in commercial boiler systems, are used to distribute heating water to a building at a single temperature setpoint.
A typical building will have loads that can be supplied with variable water temperature, such as ventilation, perimeter radiant heating and domestic hot water.
A TGH system can distribute variable water temperatures to match building loads, improving overall system efficiencies.
As water moves within the header, and in/out of the header, a thermal gradient is developed in the distribution system that allows for multiple temperature supplies with minimal controls.
Applications
A TGH can be arranged such that both heating and cooling is possible from the same header. With the integration of heat pumps and high temperature sources (e.g., condensing boilers) a wide array of heating and cooling requirements can be met with significantly reduced controls.
Low temperature return fluids can be directed into the condenser of a heat pump supplying cooling applications, with the output fluid being piped further upstream within the header to re-supply low or medium temperature heating loads.
A TGH system can be applied when there are accessible sources of thermal energy (such as ventilation exhaust), and a simultaneous heating load, such as building heating or domestic hot water production. It can also be arranged to collect heat from external thermal resources such as outdoor air, Geo-storage etc.
Technology Benefits
Thermal gradient headers offer significant benefits over traditional hydronic heating & cooling distribution:
Decreased carbon emissions, as electricity is utilized by the heat recovery chiller to produce hot water
The system is expandable, and can be designed to add future loads / sources
Minimal increase in control systems / compatible with existing DDC
