Saving Energy in Michigan's Federal Facilities
State Energy Office Energy Audit leads to $115,167 in Energy
Improvements at the General Services Administration Theodore Levin
State of Michigan & Federal Energy Management Program (MI-FEMP)
MI-FEMP Preliminary Energy Audit Results
The Levin Federal Courthouse is a multi-story, 605,285 square
foot, masonry building that was constructed in 1934 in Detroit.
In 1999, the MI-FEMP Initiative completed an energy use analysis
to gauge this building's energy consumption for the previous 12-month
period. The total energy bill for that period was $629,842 with
electricity accounting for more than 70% or $457,832 of the bill.
The initial audit identified many energy efficiency opportunities
such as reducing electric loads by upgrading fan and pump motors
to premium-efficiency models and optimizing chiller plant operation.
Other opportunities were installing demand limit controls, reducing
lighting use and improving cooling tower efficiency. Also, energy
use reduction could be achieved by replacing disintegrated ductwork.
The initial energy audit recommendations presented this facility
with significant cost saving potential while suggesting many ways
to improve building energy-using equipment and to increase occupant
Energy Efficiency Measures Implemented at the Levin Courthouse
The Levin U.S. Courthouse energy efficiency retrofits were installed
at a cost of $115,167 with annual savings of $26,757 providing
a payback of 4.3 years.
New Faucet Aerators
Of the average 70,000 cubic feet of water used per month at the
Levin Courthouse, 20,000 cubic feet is considered hot water usage
and the rest is for drinking and flushing. The current faucets
use 3.5 gallons per minute. The proposed new faucets with a 1-gallon
per minute aerator will reduce facility water usage and steam
heat usage by 14,400 cubic feet and save $316 per month.
Total investment = $29,000; annual savings = $7,980; payback =
Retrofit of exit and bath lamps with LED
Due to the unique nature of the existing exit lighting and matching
men's/ladies room fixtures in the main corridors, an additional
cost for new exit lenses was needed. The re-engineered estimated
for replacing 60 exit signs @ 40 watts each with 60 signs @ 2
watts each resulted in annual savings of $1,798.
Total investment = $2,990; annual savings = $1,789; payback =
The restrooms exit sign retrofit resulted in the replacement
of 24 signs with 2-watt models generating annual savings of $719.
Total investment = $1,532; annual savings = $719; payback = 2.1
Occupancy Sensors for Men's and Ladies restrooms
The 21 restrooms fitted with the new LED signs have a total of
13.6 kW. All but one of these restrooms is located on outside
walls with natural window lighting. Occupancy sensors with demand
control will provide annual savings of $3,278.
Total investment = $16,888; annual savings = $3,278; payback =
Replace low/high efficiency motors with premium efficiency
Currently, burned-out motors in facilities are rewound. Premium
efficiency motors should be purchased instead for all motors under
20 hp that burn out. Though a cost premium has to be paid for
premium efficiency motors, the energy savings over the life of
the motor will more than pay for this cost premium. Premium efficiency
motors can save a substantial amount of electricity at a facility.
Rewound motors are typically less efficient than original motors
because of the harsh baking process used to remove the windings.
Each time a motor is rewound, efficiency can drop up to 5%. Therefore,
if a motor has been rewound more than once, even greater savings
for energy efficient motors are attained relative to rewound motors.
A thorough investigation of motors at the Levin U.S. Courthouse
resulted in the replacement of over 20 motors.
Total investment = $36,357; annual savings = $5,440; payback =
Install new software on the Andover energy management system
The energy management system did not have the ability to change
certain set points and schedule without facility staff having
to call outside contractors for assistance. In addition, the system's
method of optimizing morning start-up was not functioning nor
was it accessible to the building maintenance staff. Purchasing
a software upgrade greatly enhance the productivity of the maintenance
staff and now provide increased energy savings by optimizing the
start times of the equipment.
Total investment = $15,400; annual savings = $4,752; payback =
Install new remote control (radio frequency) relays for load
shedding and after-hours energy savings of equipment not accessible
via control wiring
Water coolers were the object of this energy management opportunity.
The water coolers have the ability to operate 24 hours per day
if called to do so by the system thermostat. By installing a simple
radio controlled relay for start/stop and demand control operations,
energy savings was achieved with annual demand charge savings
of $2,124 and energy savings of $675. A total of 41 receivers
and 10 transmitters were installed.
Total investment = $13,000; annual savings = $2,799; payback =