SCHOOL OF PUBLIC HEALTH
WASHINGTON, D.C.
ANGIE TEJADA
MECHANICAL OPTION
DEPTH PROPOSAL
PROPOSAL - FINALIZED
Mechanical Depth
The proposed alternative consists in implementing a reversible heat pump to condition the outside air in the DOAS units, eliminating the need for coils and energy recovery wheels. The heat pump operates between the exhaust air and outside air supply streams, allowing for improved efficiency and waste heat recovery. In cooling mode, 70 °F return air is used as a heat sink instead of rejecting heat into outside air with a typical design summer condition of 95° F. For heating, 70 °F return air is used as a heat source instead of extracting heat from cold outside air.
Building Systems Integration
Natural Ventilation
Structural Breadth
This breadth topic studies the integration of natural ventilation using the existing atrium space, with the goal of reducing fan energy consumption as well as operating hours for the DOAS units. The site of the building is located in a mixed-humid region (climate zone 4A per ASHRAE classification), where outdoor air conditions are adequate for natural ventilation for up to 40% of the year. When outdoor conditions are ideal, operable windows will open and provide natural ventilation to the occupied spaces.
This breadth consists of a structural evaluation of the existing curtain wall system located in the south-east facade. The purpose of this analysis is to assess the possibility of integrating a double-skin façade in place of the curtain wall, and determine whether the current structure is adequate to support it.