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The goal of this study was to quantify the efficiency of blowers driven by electronically commutated motors (ECMs)in horizontal low-profile fan coil units (FCUs) over the typical range of operating pressure. The airflow and power of twelve FCUs from three manufactures were measured over an external static pressure (ESP) range from 0 to 125 Pa (0 to 0.5 in.w.g.) in a well-instrumented laboratory environment. The overall efficiency of blower/motor combination was also determined from the experimental measurements. Due to different ECM controls, the effect of increasing ESP on airflow andpower varies among units from different manufactures. Blowers with constant torque control may suffer from moderate to significant airflow decreases while blowers with constant airflow control maintains airflow over the tested ESP range.The overall efficiency increased with increasing ESP although drops in efficiency were measured at the higher end of ESPs at lower speeds. The maximum overall efficiency measured fromthe twelve units was under 25% while 91% of the data pointswere below 20%, which was dramatically lower than thedefault efficiency of 60 to 70% in building energy simulation programs. Statistical measures of 25% percentile, median, and 75% percentile in the overall efficiency over the tested ESPrange were identified through statistical analysis. These results provided important information on the power calculations of blowers with ECMs in horizontal low-profile fan coilunits with ESPs ranging from 0 to 125 Pa (0 to 0.5 in. w.g.).
Citation: 2020 Winter Conference, Orlando, FL Technical Papers
Product Details
- Published:
- 2020
- Number of Pages:
- 12
- Units of Measure:
- Dual
- File Size:
- 1 file , 2.1 MB
- Product Code(s):
- D-OR-20-018
