ASHRAE Journal - September 2020 - 58

2020

ASHRAE TECHNOLOGY AWARD CASE STUDIES

observed to be the lowest load times and the
most constant load times.

FIGURE 2 Building load.

4 am to 8 pm

8 am to 5 pm

350

Maintenance and Operation

330

Chiller Load (Tons)

Chiller/Building Load (Tons)
Preventing the second chiller and third
310
chiller from coming on not only signiﬁ290
cantly reduces energy cost, it also reduces
the run hours, operations and maintenance
270
cost, extending the life of the chillers by sev250
eral years. Due to the cost of a chiller being
230
approximately $1 million each, extending
210
the life of the chiller plant postpones this
investment for several years.
190
Other O&M savings are from the reduced
170
number of work orders, many of which were
150
from the facility having cold and hot spots.
12 am
6 am
12 pm
6 pm
12 am
After all measures were implemented, the
amount of work orders was reduced by
TABLE 1 Total savings.
nearly 50% from an average of 80 work orders per year
TASK
ANNUAL COST
ENERGY
for 2015, 2016, and 2017 to 47 work orders in 2018. This
SAVINGS ($) SAVINGS (KWH)
allows additional time for the staff to perform preventaChiller Plant/Waterside Equipment Optimization
$33,101
441,347
tive maintenance, which further helps with operations
Airside Equipment Modiﬁcations
$38,225
509,660
and occupant comfort.
During this process, trends and reports were created for
Annual Savings for this Project
$71,326
951,007
all the equipment in the plant, which have continued to be
available to the staff. These trends and reports aid ADTRAN Greenhouse Gas Emissions
* 143 passenger vehicles driven for one year.
in analytics and diagnostics of equipment conditions.
* 1,642,527 miles (2 643 390 km) driven by an average
Cost Effectiveness
passenger vehicle.
Implemented changes are saving ADTRAN over $71,326
CO2 Emissions
annually in energy costs with a simple payback of 1.86
* 75,593 gallons (286 151 L) of gasoline consumed.
years based off on a project cost of $133,000.
* 65,991 gallons (249 803 L) of diesel consumed.
In addition to these savings, other implemented
* 734,422 pounds (333 128 kg) of coal burned.
changes have achieved a cost avoidance equal to
* 8.9 tanker trucks' worth of gasoline.
approximately $1 million from not having to buy a
* 80.4 homes' energy use for one year.
fourth chiller since only two chillers are required.
* 117 homes' electricity use for one year.
Table 1 details the total savings.
* 3.7 railcars' worth of coal burned.
Environmental Impact
* 1,555 barrels of oil (247 225 L) consumed.
All reduction of global climate change gases (i.e. car* 85,661,940 number of smartphones charged.
bon dioxide emissions), elimination of CFCs, reduction
Greenhouse Gas Emissions Avoided
in waste discharge and other environmentally favor* 234 tons (212 281 kg) of waste reable items has been calculated using the United States
Environmental Protection Agency (EPA) Greenhouse Gas cycled instead of landﬁlled.
* 33.5 garbage trucks of waste reEquivalence Calculator. The calculation is based on a
cycled instead of landﬁlled.
950,000 kWh reduction. The calculator can be found at
https://bit.ly/3k9ecVE
Rate this Column
* 29,312 trash bags of waste recycled.
https://tinyurl.com/j3glbf8.
58

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ASHRAE Journal - September 2020

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