Free AEE CEM Practice Exam with Questions & Answers | Set: 4

What is the main reason for using instrumentation in energy audits?

A facility has the thermal cooling load profile shown in the table below. The utility rate tariff has an on-peak time-of-use billing period that begins at 10:00 a.m. and ends at 7:00p.m. Calculate the storage capacity required for a load-shifting operating strategy, to make sure that no thermal cooling Is generated by the chiller during the on-peak utility rate period.

[Question from the previous image, which was about storage capacity for load shifting, but the table was missing]

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.

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 100-kW electrical load has a power factor of 75%. What capacitance, in KVAR, will improve the power factor to 95%?

A desk lamp is located inside a windowless office. The office is heated during the winter and cooled during the summer. When the lamp is switched on, how much of the energy consumed by the lamp becomes heat in the office space?

Which electric rate tariff would best cost justify a thermal energy storage (TES) system?

A heat pump water heater has an annual average coefficient of performance (COP) of 2.1 and heats water from 15°C to 50°C. Hot water use is 100 liters per day, 365 days/yr. The electricity cost is $0.10/kWh. What is the annual water heating cost? (The specific heat of water (C) is 4.2 kJ/kg-°C.)

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?