Experimental Evaluation of HVAC Energy Conservation Options for Modular Classrooms

摘要

Three modular classrooms at one school campus and two modular classrooms at a second campus were monitored to measure the effectiveness of the heating ventilating and air conditioning systems and to compare the energy savings made possible by several types of HVAC system design improvements. All of the classrooms are similar in construction and all are located in similar environments near Raleigh, NC. One classroom at each campus has a water source heat pump designed specifically for mobile buildings. The water exchanges heat with the earth and the atmosphere through a PVC heat exchanger that lies on top of the ground in the crawl space. The three classrooms at the first campus are occupied throughout the summer. One heat pump is standard, but one water source heat pump and one air source heat pump are equipped with exhaust air-to-inlet air heat exchangers that recover energy in the ventilation air. The second campus is closed in the summer. There the thermostats are programmed for weekend and nighttime set back, but there is no ventilation energy recovery. Data loggers recorded the temperatures of the indoor air and outdoor air at one-minute intervals throughout the year. Switches were installed on the doors to record the times that they were open, and indoor CO{sub}2 levels were recorded at one-minute intervals for typical days in each season. The capacity, load, and COP of each heat pump were established approximately at various conditions by measuring the electrical power requirement, the duct airflow rate, the air temperatures, and the indoor and outdoor humidity. The refrigerant suction and discharge pressures were measured periodically throughout the test period.