CEM study materials
CEM study resources

CEM case studies

CEM · Put your knowledge to work in context.

The Certified Energy Manager (CEM) is a personnel certification administered by the Association of Energy Engineers (AEE) for professionals who optimize the energy performance of facilities, buildings, and industrial plants. AEE describes the CEM as a systems integrator for electrical, mechanical, process, and building infrastructure who analyzes cost-effective solutions to reduce energy consumption, and notes that CEMs often serve as team leaders developing and implementing organizational energy management strategies. The credential targets energy managers validating their experience, consultants specializing in building energy efficiency, building owners and managers who want to understand how savings can finance projects, and anyone developing efficiency or sustainability programs. AEE states that since 1981 more than 40,000 professionals from over 100 countries have participated in the CEM program, and that the certification is accredited by the ANSI National Accreditation Board (ANAB) under ISO/IEC 17024, with the Spanish programs accredited by ENAC. The CEM case studies are 5 cases and about 3,108 words.

1

Retail Supply Versus Capacitors at a Ratcheted Demand Tariff

A 320,000 ft² distribution center in a deregulated state buys full-requirements service from the incumbent utility. Its 12-month peak is 1,450 kW, set last August; the current-month peak is 1,200 kW.

652 words, about 3 min
2

Economizer and Static-Pressure Faults in a VAV Office

An 18-story Class B office built in 1988 has a central VAV system with a 250-ton centrifugal chiller, two 100-hp supply fans with inlet guide vanes, and electric reheat in 40 perimeter zones. BAS trends show AHU-2 supply static at 1.45 in.

702 words, about 4 min
3

Rewind or Replace a Failed 100-hp Compressor Motor

A 100-hp, 1,800-rpm, 460-V totally enclosed fan-cooled motor drives a plant air compressor. It failed after 11 years.

578 words, about 3 min
4

Battery Dispatch Under a Cloud-Edge Peak Event

A 180,000 ft² hospital campus has a 1,200 kW peak, 450 kW of rooftop PV, and a 250 kW/500 kWh lithium-ion battery. The utility tariff has a 22/kW-month demand charge based on the highest 15-minute interval and TOU energy: 0.16/kWh on-peak (2-7 p.m.

595 words, about 3 min
5

Steam Trap Losses, Condensate Return, and Blowdown Recovery

A chemical plant operates a 40,000 lb/h, 150-psig natural-gas boiler at 82% annual fuel efficiency. Steam serves three processes.

581 words, about 3 min