ASHRAE Journal - June 2021 - 61

FIRST PLACE | 2021 ASHRAE TECHNOLOGY AWARD CASE STUDIES
FIGURE 1 Key building innovations.
1
2
3
Triple Pane Glazing is Optimized to Allow for Views of
Downtown and Daylight Access While Still Managing
Exterior Noise and Envelope Loads
Central Staircases Provide Optimized IEQ and Encourage
Physical Movement
Rain/Condensate Water Storage Tank for Cooling Tower
Makeup Water
4 Geoexchange
5 Drinking Water Treatment
6 Dedicated Outdoor Air System
7 Perimeter Radiant Panels
8 Condensing Boilers
9
1
5
3
4
AHU, Double Total Energy Recovery Wheel,
Humidifi cation
10 Cooling Towers Can Operate as Waterside Economizer
11 Generator
12 Exhaust Air
13 Chiller
keep the chill off the glass, and fans are off when not
needed.
The central plant includes condensing boilers, a ring
of geoexchange wells and waterside free cooling to
use natural sources of cooling when possible. When
mechanical cooling is needed, centrifugal chillers
42.6% more energy effi cient than code requirements
support building requirements. Modeling sized a reuse
water storage tank to offset predicted 60% of cooling
tower makeup with collected rainwater and AHU
condensate.
Daylight and glare modeling were performed
throughout the design. Automated window shades
were specifi ed in the fi nal design to ensure views and
daylight penetration could be maximized while minimizing
solar glare. Climate and resiliency analysis
were done in conjunction with one another to inform
the design approach. A centralized drinking water
treatment system to manage organics, sediment and
microbials treats all drinking stations throughout
the building. Local water quality was tested to ensure
acceptable levels.
User experience is central to the operation through
local temperature control, locally addressable lighting
controls, occupancy sensors, CO2 and ozone sensors for
ventilation management, and automated solar shading
2
7
8
12
9
6
13
11
10
and lighting control integration.
Energy Effi ciency
Reducing annual energy use and energy cost was a
priority. Integrated design efforts involving extensive
energy modeling began during conceptual phases
and continued through the design's duration. Energy
modeling results were a key driver of fi nal design
selections. The modeling baseline followed ASHRAE
Standard 90.1-2010 Appendix G. The building was
permitted under IECC 2009. The project achieved
57% energy savings with modeled energy use intensity
(EUI) of 50.6 kBtu/ft2·yr (574.6 MJ/m2·yr) versus the
117.5 kBtu/ft2·yr (1334.4 MJ/m2·yr) baseline.
Two 2012 Commercial Buildings Energy
Consumption Survey (CBECS) benchmarks are most
relevant: offi ces within the ASHRAE cold climate zone
(85.4 kBtu/ft2·yr [969.8 MJ/m2·yr]) and offi ces within
the east north central census zone (84.8 kBtu/ft2·yr
[963 MJ/ m2·yr]). Energy consumption is about 40%
lower than the CBECS benchmarks. The fi rst full calendar
year of metered data (2019) showed an EUI of
53.1 kBtu/ft2·yr (603 MJ/m2·yr), which is within 5% of
the model.
Metered electric (Figure 2a) is lower than model predictions
due to greater load diversity. The design team
J U N E 2 0 2 1
a s h r a e . o r g
ashrae .o rg
ASHRAE JOURNAL
A S H
A E J O U R N A L
6 1
Illustration ©Affi liated Engineers, Inc.
https://www.ashrae.org/
ASHRAE Journal - June 2021

Table of Contents for the Digital Edition of ASHRAE Journal - June 2021
