A facility owner is considering installing a new chiller. The installed project cost will be $300,000. The annual savings from the energy-saving project will be $45,000 for the 20-year life of the chiller. If an energy-service company requires a minimum 20% return on investment (pre-tax), will the energy-service company agree to finance this project?
Using the natural gas combustion efficiency tables in your workbook, find the combustion efficiency (based on higher-heating value) of a natural-gas-fired boiler if the excess air level is measured at 31.9% and the stack temperature rise is 187.8°C.
A 50-kW induction motor (1,500 rpm synchronous speed) has a nameplate full-load rotational speed of 1,455 rpm. Field measurements show the actual rotational speed is 1,475 rpm. Using the slip method, calculate the partial load factor of the motor.
A facility has the thermal cooling load profile shown in the table below. The utility rate traffic has an no-peak time-of-use period that begins at 10:00 a.m ends at 7:00 p.m. What chiller capacity (output) is required for a load-leveling operating strategy?
[Question from the previous image, which was about chiller capacity for load leveling, but the table was missing]
Why do electric utility companies transmit power at high voltages?
SELECT THE CORRECT ANSWER
A controlled valve is full closed when it gets a signal of 4 mA. The valve is full open when it gets a signal of 20 mA. With a control signal of 8 mA, what is the valve position?
Which of the following best describes a dead band in controls?
The temperature in an unconditioned mechanical room is found to typically be around 23°C warmer than ambient air. If the air intake of an air compressor located in the mechanical room is routed through a nearby wall so that ambient air is fed directly to the air compressor's intake, what impact can be expected on the air compressor's energy requirement?
A piece of equipment costs $250,000 to buy and install. The annual operating cost for the equipment is $50,000 per year. The equipment will last 15 years. After 15 years, the equipment will have no net salvage value. The annual interest rate is 10%. What is the present value of the life-cycle cost to own and operate the equipment? Use end-of-year annual cash flow analysis.
Natural gas costs $4.80/GJ. How much does it cost to heat 500 liters of water from 18°C to 50°C using a natural gas water heater with an efficiency of 85%? [The efficiency and fuel price are both based on HHV. The specific heat of water (C) is 4.2 kJ/kg-°C.]
A white paper with black text and numbers
AI-generated content may be incorrect.