honorable mention other institutional buildings, new … · 2019-07-25 · april 2017 ashrae.org...

A S H R A E J O U R N A L a s h r a e . o r g A P R I L 2 0 1 72 8

BUILDING AT A GLANCE

Carrie Kelty is a mechanical engineer at CMTA in Lexington, Ky.

Berea College students first harvested wood for a new college dorm in Kentucky. Then, they used mules to transport the logs, milled them, and shipped the lumber to the college. These were just the first steps in their journey of 'living while learning,' because they also used that lumber to help build the dorm. It's not just the students who learned. The design team learned how to give residents control over their environment and give feedback on performance using intelligent meters and controls.

Deep Green Residence Hall

Location: Berea, Ky.

Owner: Berea College

Principal Use: Residence hall

Includes: 66 college dorm rooms

Employees/Occupants: 120 students in 66 dorm rooms

Gross Square Footage: 42,000

Conditioned Space Square Footage: 42,000

Substantial Completion/Occupancy: August 2013

Occupancy: 100%

National Distinctions/Awards: LEED Platinum Certi-fication & Living Building Challenge Petal Recognition

BY CARRIE KELTY, P.E., MEMBER ASHRAE

Living While Learning

HONORABLE MENTIONOTHER INSTITUTIONAL BUILDINGS, NEW

The Deep Green

Residence Hall's EUI is

34 kBtu/ft2·yr (386.1 MJ/m2·yr).

Energy consumption is signifi-

cantly lower than the Standard

90.1-2007 baseline case due to

the use of geothermal systems,

low-flow plumbing fixtures,

building control systems, and

building envelope testing.

35 Years of Excellence

2017 ASHRAE TECHNOLOGY AWARD CASE STUDIES

This article was published in ASHRAE Journal, April 2017. Copyright 2017 ASHRAE. Posted at www.ashrae.org. This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE. For more information about ASHRAE Journal, visit www.ashrae.org.

A P R I L 2 0 1 7 a s h r a e . o r g A S H R A E J O U R N A L 2 9

ABOVE The building was constructed using materials that did not appear on the International Living Future Institute's Red List. LEFT Pump skid (chilled water, hot water, and geothermal water pumps) and modular chiller.

The new three-story, 42,000 ft2 (3902 m2) Deep

Green Residence Hall in Berea, Ky., has received LEED

Platinum certification and has achieved Living Building

Challenge (LBC) Petal Recognition by the International

Living Future Institute.

The team also took extreme measures to limit the col-

lege’s global environmental impact through compliance

with the LBC “Red List,” which prohibits the use of mate-

rials that are detrimental to the occupants and the planet.

Energy EfficiencyModels predicted the residence hall would consume

35.1 kBtu/ft2·yr (398.6 MJ/m2·yr). According to LEED

2009-NC, this predicted consumption was the equiva-

lent of a 55% reduction of energy use when compared to

ASHRAE Standard 90.1-2007, of which 14% was from the

photovoltaic renewable energy system. According to the

2003 CBECS, residence halls across the country, on aver-

age, have an EUI of 90 kBtu/ft2·yr (1022 MJ/m2·yr). Deep

Green's EUI is 34 kBtu/ft2·yr (386.1 MJ/m2·yr). Figure 1

shows a graphed comparison of actual monthly energy

use versus modeled energy use (proposed building and

Standard 90.1-2007 baseline). The energy consumption

is significantly lower than the baseline case due to the

use of geothermal systems, low-flow plumbing fixtures,

building control systems, and building envelope testing.

The building owner preferred fan coil terminal units

for the resident rooms, with hot and chilled water pro-

vided by a geothermal heat recovery chiller central plant

system. When the building is in cooling mode, the con-

denser loop (waste heat) is used to provide any building

heat needed. Two dedicated outdoor air systems were

provided with energy recovery wheels to precondition

the incoming outdoor air. The facility also uses a direct

digital energy management and temperature control

system that monitors and controls all HVAC equipment

and domestic water heating equipment.

According to the U.S. Energy Information

Administration, the energy consumption from hot water

heating in an average residence hall is 25%. To reduce

energy, low-flow fixtures and geothermal water-to-

water heat pumps were used in the design of this build-

ing, reducing water heating by 88% from a Standard

90.1-2007 baseline building.

Occupancy sensors and plug load controls were also

used to reduce electrical consumption. The occupancy

sensors are linked to the HVAC controls to determine

unoccupied setback times, and a window sensor shuts

off the fan coil units when the window is opened. The

networked lighting control system also uses tightly

defined schedules to automatically control lights in

areas that use fixed schedules. The energy-saving fea-

tures earned all 35 LEED Energy and Atmosphere points

and three regional priority credits and resulted in 35%

less energy use than other residence halls in the region

and savings of 55% in annual energy costs.

One important aspect of energy efficiency that is com-

monly overlooked is the actual building construction PH

OTO

CRED

IT: ©

SAM

FRE

NTRE

SS

PHOTO CREDIT: ©SAM FRENTRESS

FIGURE 1 Annual energy consumption comparison of modeled versus actual data.

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

700,000

600,000

500,000

400,000

300,000

200,000

100,000

0

Ener

gy U

se (k

Btu)

Energy Use Actual Deep Green Residence Hall Modeled Deep Green Residence Hall Standard 90.1 Baseline Model Residence Hall



performance. Highly efficient materials were used in con-

struction to reduce energy, but the facility failed the initial

building pressurization test. With thermal imaging, the

points of faulty construction were presented and resolved

to maximize the efficiency of the building envelope.

Indoor Air Quality (IAQ) and Thermal ComfortTwo 100% outdoor air energy recovery units are used

to provide the necessary ventilation for the space in

accordance with ASHRAE Standard 62-2007. With the

importance of fresh air and the correlation to learning

and attentiveness, the design team wanted to provide

more than the code-required ventilation air to improve

the overall student environment. Table 1 indicates the

ventilation air provided for the building.

Some features were added to the building to assist with

compliance with ASHRAE Standard 55-2004. The design

of the forced air HVAC system maintained a 40 fpm

(0.2 m/s) velocity of the distributed air system. While the

temperature ranges in the building were allowed to vary

between 75°F and 68°F (24°C and 20°C) at 60% and 30%

RH, ceiling-mounted high volume, low velocity fans with

variable speed control were also used to increase thermal

comfort, depending on individual comfort and metabolic

rate. The operable windows for each residence hall room

allow further individual control of the indoor environ-

ment. These are connected to the HVAC system via con-

tacts to prevent operation of the mechanical heating and

cooling units when the windows were open.

The indoor air and thermal comfort of the space was very

important to Berea College. In conjunction with the design

and construction of the residence hall, the design team

also performed a study on other residence halls at Berea.

Mold was growing in some of their facilities, and after fur-

ther review found that multiple shower spaces were being

under- or minimally ventilated. Based upon this review,

the multi-occupant showers in Deep Green provided

increased exhaust ventilation. Berea followed up with sur-

veys on occupant comfort. Some initial challenges with the

window connectivity caused the heat recovery chillers to be

commanded off in the building; however, through commis-

sioning and reprogramming, this was issue was alleviated.

InnovationDeep Green’s innovation story demonstrates that the

residence hall is more than just a building. The inno-

vative aspects can be summarized as the use of local

resources with engagement of the community, use of the

building as an educational opportunity, and the use of

technology to allow the building’s operation to be com-

municated via metrics for feedback. From inception to

present, the collaboration effort focused on all stake-

holders creating a living and learning environment and

constantly improving the facility to push the envelope

of innovation to be a global leader in sustainability and

carbon footprint reduction.

In one truly unique example, the Deep Green team

collaborated with Berea College’s Forestry Department

to use locally harvested wood. The result was a signifi-

cant educational story where the building’s 100% FSC-

certified wood was harvested, logged via mule, milled,

shipped, and installed. The benefit was that students

obtained hands-on, real-world experience on the build-

ing material manufacturing process. The building had

source control with local regional materials and mini-

mal impact on the environment and authority over con-

struction and installation, which eliminated building

PHOT

O CR

EDIT

: BER

EA C

OLLE

GE

PHOTO 1 Mule Team Harvest. Students logged wood with a mule team to keep the carbon footprint of Berea's new Deep Green Residence Hall as small as possible.

TABLE 1 Ventilation Air Requirements. With a growing body of evidence document-ing the importance of fresh air to learning and attentiveness, the design team wanted to provide more than the code required ventilation air to improve the overall student environment.

SYSTEM NAME REQU IRED OUTDOOR AIR DESIGN OUTDOOR AIR

ERV-1 East Wing 2,028 cfm 2,450 cfm

ERV-1 West Wing 1,927 cfm 2,450 cfm



pollutants such as VOCs used in varnish and paints. The

technology used was traditional yet proven, with value

to sustainability and community that today’s culture and

Berea’s student can appreciate.

The next student group to get involved in Deep Green

and use the harvested wood was the Berea Student

Crafts Department. These students provided custom

furniture for the building, which included 123 sets of

desks, two-drawer chests, and 40 end tables and coffee

tables for the building's common areas.

Numerous other building items were furnished by local

students. As a result, the crafts are 100% FSC-labelled with

sustainably harvested materials. The ability to control

what items are being brought into the building continued

to improve indoor air quality while increasing campus

pride by investing and educating the students.

Innovation at Deep Green is not limited to the design and

construction phases of the building. The design included

numerous “living learning” opportunities throughout the

project such as letting users and occupants determine how

to operate the building. This includes comfort and environ-

mental options that are individual-based such as the oper-

able windows that shut off local HVAC units when used,

highly controllable ceiling fans that are ultra low energy

use models to allow air distribution to determine personal

comfort, ENERGY STAR-rated appliances, operational cul-

ture in place to allow drying in the rooms, receptacle plug

load control via manual switches, and lighting controls

with daylight and dimming options to allow user prefer-

ence controllability of the lighting.

The metrics and real-time data from the building opera-

tion are collected, archived, and shared in real-time access

to allow feedback on how the decisions are impacting

building performance. The result is a symbiotic relation-

ship between the residents and the building itself. Energy

use is reduced while occupant satisfaction is increased.

These local and web-based dashboards also improve

awareness and create a culture with occupant buy-in.

Operation and MaintenanceMaintenance of the geothermal system was a significant

concern for Berea College in making the system selection.

The majority of campus is heated and cooled by a central

utility plant that provides hot and chilled water to each

building through a network of underground pipes. This

allows for the bulk of the equipment to be larger and cen-

trally located for ease of maintenance. Another concern

with geothermal systems was having compressors in each

student's room. The compromise was to install a geother-

mal central plant that would serve this building as well as

an adjacent resident hall. This kept compressors out of the

student's rooms and in a central location while maintain-

ing high energy efficiency.

The design team analyzed the maintenance costs that

would be expected for a period of 25 years. As part of the

life-cycle cost analysis, maintenance costs for the geother-

mal central plant with room fan coils were compared to

campus central plant with room fan coils (Figure 2).

As expected, the maintenance costs for the geothermal

central plant exceeded that of a building supplied with

campus chilled water and campus hot water. The energy

costs between the two systems were compared (Figure 3).

The geothermal central plant was shown to be more

efficient than the existing campus central plant. When

we combined the energy costs with the maintenance

costs (Figure 4), we saw that the geothermal central plant

was still economically viable. Lighting controls were also

simplified to occupancy sensors and time clocks to allow

users maximum flexibility and limit complicated net-

worked lighting controls.

Once the building was opened, there was initially a

larger than expected cost in the chiller maintenance as

the modular geothermal chillers were tripping off due to

fluctuations in load or water flow. After some modifica-

tions from the manufacturer and some tuning from the

controls contractor, the nuisance trips stopped, and the

building maintenance costs have been reported as very

close to the model. Full commissioning of the systems

also contributed to the smooth operation of the systems.

Cost EffectivenessBerea is a non-tuition college, and the bulk of the oper-

ating income is supplied via donations; therefore, every

budget dollar had to be spent efficiently. The build-

ing was built for approximately $313/ft2 ($3,369/m2),

which includes the solar array and geothermal provi-

sions for future buildings. Of that amount, $40.17/ft2

($432.39/m2) was spent on the building mechanical

system including $5.59/ft2 ($60.17/m2) of geothermal

wellfield and central plant for a neighboring building,

which results in a total mechanical system cost for the

residence hall of $34.58/ft2 ($372.22/m2).

The cost of the mechanical system was closely reviewed

during the design process as part of a life-cycle cost analysis


A P R I L 2 0 1 7 a s h r a e . o r g A S H R A E J O U R N A L 3 3

that examined the overall mechanical system cost, includ-

ing the expected utility and maintenance cost, for the first

25 years of occupancy. The designed system was ultimately

compared to an energy code baseline system and a high

performance mechanical system using the campus central

heating and cooling plants in lieu of the geothermal design.

These options were reviewed with the Board of Trustees of

Berea College to make the final system selection.

The life-cycle cost analysis showed that despite being

$6/ft2 ($64.58/m2) more than the code baseline system and

$3/ft2 ($32.29/m2) more than the campus central plant

option, the designed system offered an attractive payback

period for the college. When compared to the energy code

baseline system, the high performance system designed

shows an energy and maintenance system savings over 25

years of $1,957,000 and a payback period of 8.5 years.

The comparison to a high performance design using

the campus central plant showed the cumulative sav-

ings over 25 years as $275,000 and a payback period

of 15 years (Figure 5). The cost estimate for the central

plant system is based on using existing plant capac-

ity and does not include any dollar amount or future

costs for replacement of chillers or boilers. These cal-

culations were completed by using ASHRAE published

maintenance and service rates from the 2011 ASHRAE

Handbook—HVAC Applications for each system type and

an annual increase in maintenance costs of 2.5%. The

utility calculations are based upon the current campus

utility rates with escalation of 4.5% annually. All energy

use data is modeled data and consistent with the project

LEED-certified energy model.

FIGURE 5 Maintenance, Energy, and Water Cost Comparison. A high performance, geothermal system shows energy, maintenance and water savings of almost $2 million over 25 years.

$3,500,000

$3,000,000

$2,500,000

$2,000,000

$1,500,000

$1,000,000

$500,000

$01 3 5 7 9 11 13 15 17 19 21 23 25

Years

Code Baseline System Connected to Campus Central Plant (90 EUI) High Performance Building as Designed (30 EUI)

FIGURES 2 (TOP), 3 (TOP RIGHT) AND 4 (BOTTOM RIGHT) As part of the life-cycle cost analysis, maintenance costs (Figure 2) and energy costs (Figure 3) for the geothermal central plant with room fan coils were compared to campus central plant with room fan coils. When the maintenance costs were combined with the energy costs (Figure 4), the geothermal plant was economically viable.

Geothermal Central Plant (Designed – 30 EUI) Connect to Existing Central Plant (45 EUI)

1 3 5 7 9 11 13 15 17 19 21 23 25

$350,000

$300,000

$250,000

$200,000

$150,000

$100,000

$50,000

$0

Years

$2,000,000

$1,500,000

$1,000,000

$500,000

$01 3 5 7 9 11 13 15 17 19 21 23 25

Years

$2,000,000

$1,500,000

$1,000,000

$500,000

$01 3 5 7 9 11 13 15 17 19 21 23 25

Years

Figure 2: Maintenance cost comparison. Figure 3: Energy cost comparison.

Figure 4: Maintenance and energy cost comparison.



Environmental ImpactThis project received the prestigious Petal Recognition

through the International Living Future Institute. As

part of this compliance process, the design team had to

tackle one of the major imperatives: Energy, Water, or

Materials. Given Berea’s previous positive experience on

projects with Energy and Water initiatives, they decided

to pursue the Materials imperative.

Berea’s national leadership in pursuing environmental

stewardship played a large role in this decision, as the

Materials imperative would require the project to be

constructed with materials that did not contain chemi-

cals listed on the International Living Future Institute’s Red

List (http://tinyurl.com/z5xctad). The Red List is made up of

known carcinogenic chemicals and to promote the overall

health of the building seeks to remove all such chemicals

from the built environment. The team felt that if this

could be achieved on the scale and size of this project, it

would be a driver for positive change moving forward.

Seeking compliance with this imperative was oner-

ous and required a level of product vetting that went far

deeper than component/system performance. It required

rigid determination to press through to a "molecular

level" understanding of products and systems.

Roadblocks to obtaining this information were numer-

ous, but the overall goal of promoting industry transpar-

ency, an improved building process, and defining value to

systems and components that were compliant and trans-

parent made the overall process one worth pursuing.

The environmental impact associated with Red List

compliance is impossible to calculate mathematically,

but its impact on occupants as well as manufacturers

and transparency in the future cannot be underesti-

mated. What can be calculated and quantified is that

during construction 89% of construction-related waste

was diverted from landfill sites. Construction material

specified and installed on this project contained a total

of 36% post-consumer recycled content. Additionally,

the building’s superior energy performance saves 283

metric tons of CO2 emissions per year, to which the

U.S. EPA has assigned a social cost of carbon emissions

avoided at a range of $3,100 to $29,700 per year.


www.cmta.com

honorable mention other institutional buildings, new … · 2019-07-25 · april 2017 ashrae.org...

Documents