If the building owner wants to decrease the annual energy cost for operating the building, which of the following would be the best design approach?

A rectangular office building is located in an extremely humid climate and is shaded by very large adjacent buildings on all four sides.

If the building owner wants to decrease the annual energy cost for operating the building, which of the following would be the best design approach?
A . Install glazing with a higher solar heat gain factor
B . Install photovoltaic panels on the sides of the building
C . Increase outdoor air intake quantities during summer months
D . Recover waste energy through exhaust air energy recovery systems

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Answer: D

Explanation:

The best design approach for the office building is D. Recover waste energy through exhaust air energy recovery systems.

This is because:

– Installing glazing with a higher solar heat gain factor would increase the cooling load and energy consumption of the building, especially in an extremely humid climate where heat gain is high1.

– Installing photovoltaic panels on the sides of the building would generate electricity from solar radiation, but it would not reduce the cooling load or energy consumption of the building, unless the electricity is used to power a heat pump or other cooling device2.

– Increasing outdoor air intake quantities during summer months would provide more fresh air to dilute the indoor pollutants and improve the indoor air quality, but it would not reduce the cooling load or energy consumption of the building, unless it is combined with a ventilation system that recovers waste energy from the exhaust air stream34.

An exhaust air energy recovery system (ERV) is a type of mechanical ventilation that uses a heat exchanger to transfer heat between two streams of air: one that enters the building and one that exits. The ERV pre-cools and dehumidifies the incoming ventilation air bysending the rejected heat into the exhaust airstream to cool the condenser coil at a lower temperature. This reduces both the cooling load and energy consumption of the building, as well as improving its indoor humidity levels34. An ERV can also provide some fresh outdoor air to meet ASHRAE Standard 62 ventilation rates5.

Therefore, an ERV is a more efficient and effective design approach than glazing, photovoltaic panels, or increased outdoor air intake quantities for reducing the annual energy cost for operating an office building in an extremely humid climate and shaded by very large adjacent buildings on all four sides.

References: 1: LEED v4: Building Design + Construction Guide – U.S. Green Building Council 2: LEED AP BD+C Exam | U.S. Green Building Council 3: Energy Recovery Systems – Nortek Air Solutions 4: Energy Recovery Ventilators – Greenheck 5: Mechanical Ventilation Types: Exhaust, Supply, Balanced & Energy Recovery