NAU’s Engineering building is currently heated from a heated water supply from the south campus natural gas heating plant called the high temperature hot water supply (HTHW). The heating plant supplies water at 190˚F to the Engineering building, as well as every other building on South campus. The HTHW is supplied to the Engineering building's heat exchanger, where the heat is passed through a hydronic loop and is delivered throughout the building as needed. When the building’s temperature is too low, the building demands more HTHW from the heating plant. When the building heats up, the demand from the heating plant is decreased.
The team is looking into Evacuated Tube Solar Thermal panels to provide the heating for the building. These panels insulate the heat from the sun within a glass tube with an aluminum rod center. The heat travels up the aluminum rod until reaching the manifold, where the heat is transferred to the buildings water supply that runs through the manifold. The team is going to need to put many of these panels in series in order to achieve the required temperature change and flow rate.
Due to this setup, the team has two main options: design a system that runs in parallel with the current hydronic loop or one that runs in series. A design in parallel with the hydronic loop will allow the water heated from the solar panels to heat the building directly. This is the ideal option. A design that runs in series will essentially act as a preheater to the heat exchanger. The water heated from the solar panels will travel to the heat exchanger and preheat the buildings water supply before it receives heat from the HTHW supply in the heat exchanger, thus lowering the natural gas demand from the building.