The document summarizes laboratory and field testing of an Advanced Load Monitoring (ALM) boiler controller called the M2G, which aims to reduce unnecessary boiler cycling. Laboratory tests at the Gas Technology Institute found the M2G reduced boiler cycles by up to 55% and gas consumption by 10-17% compared to standard controls. Field tests at apartment buildings in Illinois showed reduced cycling and 7-14% lower annual gas usage with the M2G. The research demonstrates the M2G's ability to lower energy use through more efficient boiler operation.

1. DOE Building America Case Study:
Advanced Boiler Load Controllers
May 5, 2015

2. Overview
• GREFFEN (Green Efficient Energy) Systems – Founded March 2008
• Work with many of the Fortune 100 corporations across the United States
• Greffen Systems has installed M2Gs at 19 Ford facilities in North America
• Greffen Systems has installed M2Gs at 18 GM facilities in North America
• The M2G is now a prescriptive product for both Detroit Edison and
Consumers Energy in Michigan.
– Under this program every M2G purchased qualifies for an energy rebate

3. Problem The M2G Addresses:
What is dry cycling?
Boiler firing due to standing losses rather than
building demand
• Boilers are oversized
by design
• Designed for the
coldest day of year
• Maintain set point
regardless of building
demand
Heat losses cause
unnecessary cycling,
“dry-cycling”

4. 70+ Customer Case Studies

5. Independent Studies
• Department of Energy Building Technologies Program - The
DOE recorded energy savings “up to 14%”in the study and re-
named the “emerging class” of energy conservation technology
(ALM) “Advanced Load Monitoring”.
• The Gas Technology Institute (GTI) in Des Plaines, Illinois tested
the M2G over a two year period using thermal load profiles from the
Department of Energy. GTI recorded results of between 10% and
17% with cycle reductions of up to 55%.

7. Paul Glanville
• Senior Engineer at the Gas Technology Institute (GTI) in their
Building Energy Efficiency group (7 years)
• B.S.M.E. from the University of California at Davis
• M.S.M.E. from the University of Washington in Seattle
• Registered Professional Engineer in Illinois
• Active in both ASME and ASHRAE, serving on several technical
and organizational committees

8. 8
Gas Technology Institute
> The Gas Technology Institute is an American non-profit research and
development organization which develops, demonstrates, and
licenses new energy technologies for private and public clients, with
a particular focus on the natural gas industry
> GTI’s 280,000-square-foot headquarters near Chicago, IL is home to
20+ specialized labs with equipment for design, testing and analysis
of advanced energy technologies.
> Subsidiaries working also working in
energy efficiency include: CDH Energy,
Fisher-Nickel Food Service Technology
Center, and Davis Energy Group

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Natural Gas Industry Collaboration
Emerging Technology Program
> Gas Technology Institute led, utility supported, North American
collaborative targeting residential, commercial, and industrial solutions
> ETP’s principle goal is to accelerate the market acceptance of emerging
gas technologies

10. 1010
Emerging Technology Scanning and Screening
ETP publishes technology snapshots introducing members and their
partners to the most important new technologies. Snapshots highlight
technology attributes, market and cost barriers, market readiness, and
key next steps. GTI’s ETP library contains more than 60 technology
snapshots. ETP generates roughly 20 new snapshots each year.
Learn, Coordinate, and Act
ETP hosts two member meetings annually and operates 9 working
groups. These forums present opportunities for members to learn from
each other and GTI Principal Investigators. These forums present
opportunities to coordinate critical program and project activities.
Demonstrate and Pilot New Technologies
ETP members, along with state and federal programs, fund the
deployment of new technologies for the purpose of validating
performance, characterizing market potential and implementation
strategies, and creating datasets to support new prescriptive efficiency
measures and marketing programs. In 2014, ETP has more than 15
active ET projects across residential, commercial, and industrial
markets. ETP publishes summary project reports for all active
projects, reports are available to all members regardless of funder.
Example Technology Snapshot, more
than 60 available on ETP website
GTI’s Emerging Technology Program is the source for
identifying, reviewing, and deploying emerging technologies

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What is an ALM Controller?
> Different than OTR - Which adjusts
the setpoint as a function of outdoor air
temperature, often used with “warm
weather shutdown” and/or lead/lag
controls to lessen boiler wear.
> Usually compatible in series with
these controllers, but savings may
be reduced
> Demand Controllers limit losses
from “dry cycling” - Standby losses
differentiated from building heat demand.
> These controllers monitor Supply
or Return/Supply temperatures to
differentiate. Designed only for hot
water boilers only in space heating
applications.
“Advanced Load Monitoring” Controllers:

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What is an ALM Controller?
Yields therm savings through reduced cycling
by dynamic management of the boiler
differential. Fewer, longer cycles mean:
> Longer runtime at high SSE
> Fewer pre/post purge cycles
> Fewer thermal cycles of boiler HXs
> Between 10-30% annual therm savings
claimed by vendors.
> Controller performance is highly site specific
> Limited 3rd party data published on
performance.
> 2007 study showed 12-13% savings for a
competing product

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What is an ALM Controller?
> Only suppress a boiler from firing – Don’t
turn on boilers or stop a firing boiler
> Control strategies fall into three groups -
Release a boiler to fire when:
> Demand is sensed from water temperatures
(e.g. Treturn drops 5°F after call for heat)
> Time period elapses (e.g. 10 minutes)
> Actual call for heat is detected based on
proprietary algorithms using (a) memory of
past cycling or (b) rate of change of sensed
water temperatures
> Energy savings potential greatest for: Oversized
boiler(s), boilers without OTR, large
commercial/industrial boilers, single/dual stage
> Typical boilers 50-100% oversized for
average, 15-30% for winter design conditions

14. 14
Laboratory Testing
> Compare performance of two controllers with boiler loads,
sized to low/high heating demands
> Generate heating load patterns using EnergyPlus for lab
simulation for two building types in the Chicago area, Large
Hotel and Secondary School, using automated test stand
> Simulate heating loads and determine measured/annualized
therm and cycling reductions using Chicago HDD
0
10
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0 60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960 1020 1080 1140 1200 1260 1320 1380 1440
HeatDemandatBoiler(MBH)
Time (minutes)
175F Setpoint with 5F Differential
Test Boiler Output with Controller
Scaled Heating Load Input
Example:
School
Shoulder
Season
Pattern

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Laboratory Testing
> Performed steady state and 24-hour simulated heating
tests, with high and low heating demands.
> Compared M2G and competitor with 5°F differential to
baseline operation, with 5°F and 15°F differential settings.
As it was able to, competing ALM operated with 15°F
differential also.
> Quantified reduction in boiler cycles, gas consumed, and
primary loop temperatures.
ACAP

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Laboratory Testing
Extrapolation to Annualized Savings
> Average winter and shoulder season days assumed to represent days with greater than/less
than 20°F·day respectively, boiler is inactive for days with 5°F·day or less.
> School was assumed to be unoccupied outside of 9am-6pm on weekdays, on weekends, and
holidays. When unoccupied, boiler cycles on for 1 min. during 20 min. windows
> Fuel consumption/cycling determined by season (winter/shoulder/shut down) and occupancy.
Therm Savings Reduced Cycles
Compared to Baseline with 5°F Differential
0
2
4
6
8
10
12
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16
18
M2G Comp. Baseline Comp.
5°F/3°C Differential 15°F/8°C Differential
PercentReductionvs5°FBaseline
Hotel Secondary School
0
10
20
30
40
50
60
70
80
M2G Comp. Baseline Comp.
5°F/3°C Differential 15°F/8°C Differential
PercentReductionvs5°F
Baseline
Hotel Secondary School

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Field Testing
> Four M2Gs installed at two low-rise multifamily sites, in Chicago, IL
& Cary, IL for monitoring over 2012-13 and 2013-14 seasons.
> Cary is week on/week off & Chicago has ‘control’ boiler room
> Monitoring: Boiler/Water Heater cycling, boiler and primary loop
supply/return temperatures, ambient temperatures.
> All boilers are OTR-equipped with sequencing controls and
required modifications to accommodate wider differentials
Cary site - Number of Units: 26
• Most recent NG Consumption: 13,090 therms (2011)
• Two boilers feeding central hydronic heating system
• Central DHW off two storage WHs
• Two single stage 0.4 MMBtu/hr boilers
Chicago site - Number of Units: 51
• Most recent NG Consumption: 46,770 therms (3/11 – 3/12)
• Split heating from two separate HW loops, fed by two boilers each
• Central DHW off two storage WHs
• “Control Loop” has two dual-stage 0.85/0.2MMBtu/hr boilers
• “Test Loop” has two dual-stage 1.2/0.3 MMBtu/hr boilers

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Field Testing
Cary Site: 2013-14 Season
> Reduction in boiler cycling was more muted than
expected, due to:
> Portion of first monitoring year with single boiler
operation and wider differential of 22°F
> Significantly colder than average winter
> This is reflected in higher than typical utilization factors
0.0
0.1
0.2
0.3
0.4
0.5
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0.7
0.8
10/3/13 11/22/13 1/11/14 3/2/14 4/21/14
UtilizationFactor
Boiler 1
Boiler 2
0
50
100
150
200
250
300
350
400
450
0
0.5
1
1.5
2
2.5
ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF ON
10/29 11/5 11/12 11/19 11/26 12/3 12/10 12/17 12/24 12/31 1/7 1/14 1/21 1/28 2/4 2/11 2/18 2/25 3/4 3/11 3/18 3/25 4/1
HeatingDegreeDays(F-Day)
Therms/HDDandCycles/HDD
Therms/HDD
Cycles/HDD
HDD

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Field Testing
Cary Site: 2013-14 Season
> Therm savings were observed, though strong winter
coupled with boiler sizing yield results below laboratory
testing. As such results may not be typical.
> At times, Boiler #1 cycled on for multiple hours
> Boiler cycling < 50/day on average
Data M2G Operation Shoulder* Winter Peak*
HDD
With 1140.3 2070.5
Without 1503.7 1727.2
Cycles/HDD
With 1.15 1.57
Without 1.38 1.40
% Reduction 16.5% -12.0%
Therms/HDD
With 1.29 1.45
Without 1.39 1.47
% Reduction 7.1% 1.4%
* “Winter Peak” are the weeks from 12/10 to 2/25, “Shoulder” are weeks before and after this period.

20. 20
Field Testing
Chicago Site: 2012-13 & 2013-14 Season
> Control boiler room monitored for two consecutive
heating seasons, test boiler room had heating season
with/without M2G – noticeable impact on differential.
> Noticeable reduction in cycling for “test” boiler room
compared to control boiler room, over 12-13 to13-14
heating seasons
> Average cycling reduced from 79 to 39 cycles/day
0
1
2
3
4
5
6
7
8
9
0 20 40 60
DailyAverageCycleDuration
(min.)
Daily HDD (F-Day)
2013
2014
0
5
10
15
20
25
0 20 40 60
DailyAverageCycleDuration
(min.)
Daily HDD (F-Day)
Enabled
Disabled
Control
Test
10
15
20
25
30
35
40
0
10
20
30
40
50
60
70
Differential(F)
Daily HDD (F-Day)
Enabled
Disabled
Test Boiler Room

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Field Testing
Chicago Site: 2012-13 & 2013-14 Season
> While “control room” shows similar behavior over two heating
seasons, M2G-equipped “test room” shows 14% therm savings
controlling for weather.
> Therms/HDD has strong linear function despite noisy data,
R^2 = 0.77/0.73 for 2013/14
> Roughly 48% of M2G cycles release to fire after drop in
supply/return T, 26% were after a 15 min. period, and rest are
“intelligence” based.
Data
Test Boiler Room Control Boiler Room
2013
(M2G
Disabled)
2014
(M2G
Enabled)
Change 2013 2014 Change
HDD* 1310.5 817.6 1470.1 785.8
Cycles/HDD 1.97 1.35 31.8% 3.86 3.92 -1.8%
Therms/HDD 0.96 0.83 14.4% 0.61 0.60 1.2%
* Note that 2014 sampling period has 8 fewer days

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For More Information
For More Information
> Rowley, P. and Glanville, P. Laboratory Evaluation of an Aftermarket Boiler System, Proceedings of the
2012 ASHRAE Summer Conference, San Antonio, TX.
> Glanville, P., Rowley, P., and Schroeder D. Field & Laboratory Evaluation of Advanced Load Monitoring
Boiler Controllers, Proceedings of the 2014 ASHRAE Winter Conference, New York, NY.
> Glanville, P., Rowley, P., Schroeder, D., and Brand, L. Field Test of Boiler Primary Loop Temperature
Controller, prepared by GTI for the US DOE Building America Program under contract KNDJ-0-40346-03,
2014.
http://apps1.eere.energy.gov/buildings/publications/pdfs/building_america/field_test_temp_controller.pdf
Research supported by Utilization Technology Development, a consortium of gas
utilities, the Emerging Technology Program of Nicor Gas, and the US Dept. of
Energy Building America Program.

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Questions?
Paul Glanville Frank Salensky
Senior Engineer CEO
Gas Technology Institute Greffen Systems, Inc.
Paul.glanville@gastechnology.org frank@greffensys.com