ASHRAE Journal - February 2022 - 63

TECHNICAL FEATURE
Remove Unused Water Heater
Since the building is unmanned, there is no need
for the water heater. Additionally, as per the Saudi
Aramco Uniform Plumbing Code (UPC), a water
heater cannot be installed in the same room as
the bathroom user. This ECM yields an estimated
annual savings of 500 kWh.
Decommission Unused IT Critical Load
During the audit it was found that some IT critical
equipment were unused and powered on such
as a telephone switch. For the purpose of possibly
decommissioning the switch, the power demand
and energy use were calculated. Spot measurements
indicted that it was operating 24/7 at a no-load condition
constantly drawing 37 ADC and 54 VDC (the fullload
condition is usually 50 ADC and 54 VDC). This
ECM yields a total demand and annual energy saving of
2 kW and 17,503 kWh, respectively. The energy savings
measures for both the water heater and the switch are
summarized in Table 11.
EUI Target Setting
The collective ECM implementations for the communications
building would achieve at least 25%
annual energy savings and would reduce the current
estimated building energy use intensity (EUI) from
1,900 kWh/m2·yr to 1,400 kWh/·yr (602 kBtu/ft2 · yr to
444 kBtu/ft2 · yr) reduce power demand by 8 kW with
a payback of less than three years and CO2 emissions
reduction of 150 metric tons.
EUI (target) = 1,400 kWh/m2·yr
Conclusion
It was a major challenge to start up such a practice as
there is no international standard available for communications
building energy performance benchmarking
nor an EUI. This issue stems from the fact that communications
buildings:
1. Are not defi ned in any of the 54 types of buildings
in ASHRAE Standard 100-2015 and hence there is no EUI
baseline and targets for these buildings.
2. Their EUI is confused with power usage effectiveness
(PUE) for data centers.
Despite this challenge the followed approach was
able to create a appropriate EUI and establish a
F E B R U A RY 2 0 2 2 ashrae.o rg ASHRAE JOURNAL
63
13
Decommission
Telephone Switch
17,503
2 1,400
baseline. Through implementing the defi ned energy
conversation measures, the energy consumption
was reduced by around 25% and improved the EUI to
achieve 1,400 kWh/m2·yr (444 kBtu/ft2·yr) from the
baseline level of 1,900 kWh/m2·yr (602 kBtu/ft2·yr).
This amount of saved energy has a positive impact on
the environment by reducing the impact of greenhouse
gases, which will offset 7,500 metric tons of CO2
annually.
Finally, it is recommended that the ASHRAE standards
development committee responsible for Standard 100,
Energy Effi ciency in Existing Buildings, introduce a new EUI
baseline and targets for communications buildings.
References
1. Garg, V., N.K. Bansal. 2000. " Smart occupancy sensors to
reduce energy consumption. " Energy and Buildings 32(1):81 - 87.
https://doi.org/10.1016/S0378-7788(99)00040-7
2. Hoyt, T., K.H. Lee, H. Zhang, E. Arens, T. Webster, 2009.
" Energy savings from extended air temperature setpoints
and reductions in room air mixing. " International Conference on
Environmental Ergonomics 2009.
3. Niemann, J., K. Brown, V. Avelar. Undated. " Impact of Hot
and Cold Aisle Containment on Data Center Temperature and
Effi ciency. "
4. Hoyt, T., E. Arens, H. Zhang. 2015. " Extending air temperature
setpoints: simulated energy savings and design considerations for
new and retrofi t buildings. Building and Environment 89 - 96. https://
doi.org/10.1016/j.buildenv.2014.09.010
5. Phoenix Energy Group. " How to Reduce Energy Consumption
in 5 Steps. " Phoenix Energy Group. https://tinyurl.com/2p8wf7v8
6. Von Neida, B., D. Maniccia, A. Tweed. 2001. " An analysis of
the energy and cost savings potential of occupancy sensors for
commercial lighting systems. " Journal of the Illuminating Engineering
Society 30(2):111 - 125. https://doi.org/10.1080/00994480.2001.1074
8357
TABLE 11 Water heater and IT equipment energy savings measures.
NO.
ECM
12
Remove Unused
Water Heater in
Bathroom (Also for
Code Compliance)
ENERGY
SAVING
(kWh/YR)
DEMAND
SAVING
(kW)
ENERGY
SAVINGS
($/YR)
INSTALLATION
COST ($)
SIMPLE
PAYBACK
(YR)
500
1.5
$40
https://www.doi.org/10.1016/S0378-7788(99)00040-7 http://www.doi.org/10.1016/j.buildenv.2014.09.010 http://www.doi.org/10.1016/j.buildenv.2014.09.010 https://www.tinyurl.com/2p8wf7v8 https://www.doi.org/10.1080/00994480.2001.10748357 https://www.doi.org/10.1080/00994480.2001.10748357 http://ashrae.org
ASHRAE Journal - February 2022

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