A motor operates with a normal and constant load. The electric current is measured to be 25% of the motor's nameplate rating. What does this mean?

A. The motor is operating at high efficiency

B. The motor is oversized and may be downsized to increase efficiency

C. The applied voltage is too low and should be increased to improve efficiency

D. The applied voltage is too high and should be reduced to improve efficiency

A hot-water boiler has a cut-in set point of 65°C on the hot water supply temperature and a differential set point of 10°C. What is the hot-water supply temperature that causes the boiler to turn off?

A. 55°C

B. 65°C

C. 75°C

D. It depends on the return water temperature

Which motor parameter is the most difficult to measure with precision?

A. Operating (rotating) speed

B. Output power capacity

C. Input power

D. Alternating current (AC) frequency

E. Operating load factor

What type of passive heat exchanger can wrap around an evaporator coil to precool entering air and reheat the air after the cooling coil without adding more moisture to the supply air stream?

A. Desiccant heat wheel

B. Plate and frame

C. Heat pump

D. Heat pipe

E. Run-around coil

An outdoor parking area has 25 light poles. Each pole has a 420 Watt (ballast included) high-pressure sodium (HPS) luminaire. The parking area lights are illuminated 4,500 hours per year and the electricity cost is $0.08/kWh. What is the annual energy cost reduction if each luminaire is replaced with a 220-Watt (driver included) LED luminaire?

A. $1,200/yr

B. $1,500/yr

C. $1,800/yr

D. $2,200/yr

E. $2,600/yr

How much energy (kJ) is required to heat 2 kg of water from 25°C to 2 kg of water at 100°C? (The specific heat of water (C) is 4.2 kJ/kg-°C. Assume no system losses.)

A. 420 kJ

B. 510 kJ

C. 630 kJ

D. 840 kJ

Which heat recovery device listed below can be used to preheat boiler make-up water using the heat energy from skimming blowdown?

A. Shell and tube heat exchanger

B. Regenerative recouperator

C. Desiccant heat wheel

D. Heat pipe

A steam trap with a 6-mm orifice in an 0.8-MPa steam system has failed open. The steam system is pressurized8.760 hours/yr. The steam cost is $15.00 /GJ. Using thetable below, what is the annualcost of the vented steam through the failed steam trap? ignore any condensate return issues. [The question from the previous image, which was about calculating the annual cost of heat loss through a wall, but had a discrepancy between the calculated cost and the provided answer choices]

A. $5,000/yr

B. $10,000/yr

C. $20,000/yr

D. $30,000/yr

E. $40,000/yr

An energy project implemented today saves $10,000 per year for the next 20 years. Using the 5% interest table, determine the total value of savings at the end of the 20th year?

A. $124,620

B. $146,907

C. $200,000

D. $330,660

E. $496,991

Lighting systems operate with a certain recoverable light loss factor. Control systems with photocell sensor inputs combined with dimming ballasts can be used to regulate dimming levels to maintain a continuous light level in the work space. Which of the following best describes this type of control?

A. Closed-loop controller

B. Open-loop controller

C. Demand-limiting controller

D. Demand-limiting controller

In a performance contract, which group has the greatest investment risk?

A. The company installing the energy project

B. The energy-service company

C. The equipment manufacturer

D. Risk is shared by the terms in the performance contract

What is the best type of heat exchanger to recover and transfer latent heat energy from one air stream to another?

A. Heat pipe

B. Shell and tube

C. Ceramic recuperator

D. Desiccant heat wheel

E. Run-around system