CH-93-06-1 -- Evaluation of Thermal Energy Meters as Energy Allocation Devices PDF

Centralised gas-fired boilers and chillers represent a cost-effective means for heating and cooling multi-family apartment buildings. It is, however, desirable to have an equitable method for metering and allocating the energy costs to the individual occupants. To this end, reports on the measured accuracies and operating characteristics of seven new energy meters and their individual components. The energy meters evaluated consisted of a flowmetering component, two temperature sensors, and some type of integrator to calculate the thermal energy used. The studies revealed that the main source of error for energy meters is in the flowmeter component. All of the flowmeters and energy meters exhibited errors in excess of the manufacturer's published values. The flowmeters occasionally showed poor repeatability, and their accuracy was affected by the water temperature. The commercially available signal processors, when tested with precisely simulated flow and temperature input signals, exhibited errors in energy readings exceeding plus or minus 3%. Several recommendations are offered to improve the overall accuracy of thermal energy meters.

KEYWORDS: testing, energy, meters, metering, measuring, accuracy, operations, chillers, properties, components, flowmeters, temperature, sensors, flats, integrating flowmeters, water temperature, centralised services, gas fired boilers.

Units: Dual