ASHRAE Journal - April 2021 - 63

FIRST PLACE | 2021 ASHRAE TECHNOLOGY AWARD CASE STUDIES

Measurement and Veriﬁcation

FIGURE 1 Whole building energy savings.

Baseline Energy
Business as Usual

40,000

250
200

Savings

30,000

Measured Energy

150

20,000

100

10,000

50

Total CDD-50 Per Week

Energy Consumption (kWh/Week)

50,000

Cooling Degree Days Base - 50°F
0

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2018
|
2019

Start
Of Installation
Baseline Period

Cutover
Complete
Retroﬁt Period

0

Commissioning Complete
Post-Retroﬁt Period

FIGURE 2 Hot water energy savings.

2,500

Baseline Energy

250
Business as Usual

2,000

200
Savings

1,500

150

1,000

Measured Energy

100
50

500

Total HDD-65 Per Week

Energy Consumption (Therms/Week)

area and operates 24/7. The campus
central plant provides chilled water
to the AHUs and heating hot water to
the terminal units.
This project included the design
and commissioning for end of service life replacements of the AHUs
and the building automation system
(BAS). The BAS replacement included
upgrading the existing pneumatic
terminal unit controls to direct digital
control (DDC) and implementing
best-in-class control sequences in
accordance with ASHRAE Guideline
36-2018, High-Performance Sequences of
Operation for HVAC Systems. The building remained fully occupied throughout construction.
The project achieved whole building electricity savings of 21.4%,
chilled water energy savings of
38.5% and heating hot water energy
savings of 56%, resulting in the
roughly $200,000 per year energy
cost reduction (Figures 1 through 3).

Cooling Degree Days Base - 50°F

0
0
Pre-retroﬁt baseline monitoring
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2018
|
2019
spanned January 2018 to June 2018,
Start
Cutover
while the post-retroﬁt spanned
Commissioning Complete
Of Installation Complete
November 2018 to November 2019.
Baseline Period
Retroﬁt Period
Post-Retroﬁt Period
Based on weather-normalized
measurement and veriﬁcation, the
(885.8 MJ/m2·yr), or a 38.8% reduction, bringing the
whole building energy use intensity
post-retrofit operation below the calculated ASHRAE
(EUI) was reduced by 49.5 kBtu/ft2·yr (562.1 MJ/m2·yr),
or 38.8%. Chilled water energy was reduced by
Standard 100-2015 EUI target of 85 kBtu/ft2·yr
(965.3 MJ/m2·yr).
17.4 kBtu/ft2·yr (197.6 MJ/m2·yr), or 38.5%, and heat2
ing hot water energy was reduced by 23.4 kBtu/ft ·yr
Energy Efﬁciency Features
(265.7 MJ/m2·yr), or 56%.
The signiﬁcant reduction in EUI was due in large part
Energy modeling was not performed, as
to the low energy HVAC design and implementation of
the building envelope, service water heatASHRAE Guideline 36-2018. Features of the mechanical
ing, lighting and electrical systems remained
design and Guideline 36 sequences include:
unchanged, and the HVAC systems installed meet
* Airside economizers;
the prescriptive requirements of ASHRAE/IES
* Low velocity plenum return path and variable speed
Standard 90.1-2016 and California Title 24-2016.
propeller relief fans, which use passive relief as the ﬁrst
The overall building EUI was reduced from
127.4 kBtu/ft2·yr (1446.8 MJ/m2·yr) to 78.0 kBtu/ft2·yr stage of building pressure control;
APRI L 2021

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ASHRAE Journal - April 2021

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