AHU PERFORMANCE AND CALCULATE IKWTR

Determine the required measurements: For AHU performance analysis, you’ll need to measure the following parameters:

• Flow rate of chilled water (in gallons per minute or liters per minute)
• Inlet and outlet temperatures of chilled water (in degrees Fahrenheit or Celsius)
• Inlet and outlet pressures of chilled water (in pounds per square inch or bar)

Install the ultrasonic flow meter: Follow the manufacturer’s instructions to install the ultrasonic flow meter on the chilled water pipe. Ensure proper alignment, clearances, and connection to the AHU system.

Calibrate the ultrasonic flow meter: Before taking measurements, it’s crucial to calibrate the ultrasonic flow meter according to the manufacturer’s guidelines. Calibration helps ensure accurate flow rate measurements.

Record the measurements: Start the AHU system and allow it to stabilize under typical operating conditions. Then, record the following measurements:

• Flow rate of chilled water: The ultrasonic flow meter will provide a continuous reading of the flow rate in gallons per minute or liters per minute.
• Inlet and outlet temperatures of chilled water: Use temperature sensors or thermometers to measure the inlet and outlet temperatures of the chilled water.
• Inlet and outlet pressures of chilled water: Utilize pressure gauges or transducers to measure the inlet and outlet pressures of the chilled water.

Calculate the cooling capacity (TR): The cooling capacity of the AHU can be calculated using the formula: TR = (Flow rate × Specific Heat Capacity × Temperature Difference) / 12,000 where:

• Flow rate is the measured flow rate of chilled water (in gallons per minute or liters per minute).
• Specific Heat Capacity is the specific heat capacity of water (1 BTU/lb°F or 4.186 kJ/kg°C).
• Temperature Difference is the difference between the inlet and outlet temperatures of chilled water (in degrees Fahrenheit or Celsius).
  12,000 is a conversion factor to convert BTU/hr to tons of refrigeration.

Calculate the power consumption (kW): The power consumption of the AHU can be calculated using the formula: Power (kW) = (Flow rate × Pressure Difference) / (Efficiency × Pump Motor Efficiency) where:

• Flow rate is the measured flow rate of chilled water (in gallons per minute or liters per minute).
• Pressure Difference is the difference between the inlet and outlet pressures of chilled water (in pounds per square inch or bar).
• Efficiency is the overall system efficiency (typically expressed as a decimal).
• Pump Motor Efficiency is the efficiency of the pump motor (typically expressed as a decimal).

Calculate IKW/TR: Divide the calculated power consumption (kW) by the cooling capacity (TR) to obtain the IKW/TR value

It’s important to note that the specific procedures and formulas may vary depending on the AHU system, the ultrasonic flow meter model, and any specific manufacturer recommendations. Always consult the user manual and guidelines provided with your equipment for accurate measurements and calculations.