A water source (sink) heat pump is an ideal system for conducting several experiments that demonstrate HVAC equipment and principles. The cost of a small unit ($800-1500) compared to a packaged teaching system ($13,700) permits the addition of microcomputer based data acquisition equipment. The proposed paper will report on a system that was assembled by student teams and a departmental technician with limited refrigeration experience.

The basic system consists of a nominal 28,000 Btuh water-to-air heat pump, a 38-channel data acquisition system and instrumentation. Experiments in an instrumentation course demonstrate RTD and thermocouple temperature measurement; wet-bulb, dew point and humidity measurement; pressure measurement with manometers and electronic transducers; airflow measurement with a nozzle, a hot wire anemometer and a multi-station pitot tube; water flow measurement with a venturi, a rotameter and a turbinemeter; power measurement with a solid state transducer, a tong-type wattmeter and a modified watt-hour meter. Experiments have been conducted in conjunction with HVAC courses that include: unit performance using water side or air side heat pump data; overall heat transfer coefficients of a DX coil and water-to-refrigerant coil; performance of a compressor, a fan, a constant speed pump and a variable speed pump; and head loss in ducts. Hand calculated and computer generated experimental results are compared with expected values in all experiments.

Units: I-P