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Why Invest in Building Controls?
Mary Jane Poynter – Senior Energy Consultant
Peter Hooper – Electrical Engineer
Learning Objectives
• Basic understanding of “Good, Better, Best” controls
• Benefits to adding controls (comfort, $$, maintenance)
• What needs to be done before controls
• Potential energy and maintenance savings
• How to ensure controls persist
State of Vermont and Efficiency Vermont Working Together
• 2015 H.864 Revolving Fund for State Building Energy Efficiency Projects
• Partnership to identify opportunities and implement upgrades using money from the revolving loan fund.
Vermont Energy Goals
Vermont Comprehensive Energy Plan
Reduce total energy consumption by
15% by 2025, and by >33% 2050.
State Agency Energy Plan
Reduce total energy consumption by
20% by 2025, and by 25% by 2035.
Medium energy users “always on”
Highest Energy users
“manual control”
62%
69%
Why Focus on Building Controls?
85% of HVAC systems are single zone
2011 VERMONT MARKET CHARACTERIZATION AND ASSESSMENT STUDY - Navigant
Case Study – 133 State Street Montpelier
• Retuning Approach – low cost, no cost opportunities with good savings
• Big Finds:
• Turned-off most of server room CRAC/AHUs
• Reducing run hours on AHU and ERV
• Rest temp on remaining CRAC units
• Fan coil units re-programmed to run only when a call for heat/cool
• Added static reset to chilled water loop pumps.
• Adjusted boiler loop temp reset
Kaizen Opportunity Matrix
Future? Analize
Do Next Do Now!
Low
C
ost
/Eff
ort
Hig
h
Low Savings/Impact High
90% of the upgrades were DO NOW and DO NEXT
Savings Results
• 213,000 KWh/yr
• 585 MMBTUs/yr (70 tons of chips)
• $21,000 savings per year
• $4,500 cost of upgrades
• 3 month payback
Small Buildings (1-10,00ft2)
Large Buildings (10,00ft2 - 100,00ft2)
Good • Internet Connected Thermostat
• Occupancy Sensors, Photocell and Time Clocks
• Internet Connected Thermostat
• Occupancy Sensors, Photocell and Time Clocks
• Exhaust fans on timers
Better • Advanced web connected thermostat w/fault
detection, energy analysis, basic trending &
reporting.
• Smart pumps
• Daylight harvesting, zone control of fixtures
• Pre-set control algorithms for HVAC equipment
(Schnieder Electric, Belimo, Trane, Autoflame)
• Trending, energy usage, alarms
• Advanced lighting controls (daylight harvesting, zone-
based controls, lighting profiles)
Best • Packaged energy saving controls: RTU VFD, DCV, advanced economizer
• Exhaust fans under control • Centralized lighting control • Data trending and fault detection
• DDC with remote supervisory control • Advanced analytics to predict building loading • Centralized lighting control • System level integration between lighting, HVAC,
renewables, security • Lab controls/ Security Access/Controls • Emergency power systems
Small Buildings (1-10,00ft2)
Large Buildings (10,00ft2 - 100,00ft2)
Good • Internet Connected
Thermostat (HVAC)
• Occupancy Sensors,
Photocell and Time Clocks
(lighting)
• Internet Connected Thermostat
(HVAC)
• Occupancy Sensors, Photocell
and Time Clocks (lighting)
• Exhaust fans on timers (HVAC)
Small Buildings (1-10,00ft2)
Large Buildings (10,00ft2 - 100,00ft2)
Better • Advanced web connected
thermostat w/fault detection,
energy analysis, basic trending &
reporting.
• Smart pumps
• Daylight harvesting, zone
control of fixtures
• Pre-set control algorithms for HVAC
equipment (Schneider Electric,
Belimo, Seimens, Autoflame)
• Trending, energy usage, alarms
• Advanced lighting controls (daylight
harvesting, zone-based controls,
lighting profiles)
• Wireless communication to lighting controller
• Setting light levels, grouping fixtures, setting background levels, enabling daylighting controls
Small Buildings (1-10,00ft2)
Large Buildings (10,00ft2 - 100,00ft2)
Best • Packaged energy saving controls: RTU VFD, DCV, advanced economizer
• Exhaust fans under control • Centralized lighting control • Data trending and fault
detection
• DDC with remote supervisory control
• Advanced analytics to predict building loading
• Centralized lighting control • System level integration
between lighting, HVAC, renewables, security
Essence of a Control System
People
• Programming
• Installation
• Quality Control
• Users
Stuff
• Sensors
• Controlled Devices
• Controllers
• Interface Devices
• Networks&Wiring
Tools
• Software
• Documentation
• Training
What controls to add, and why to add them? • Why do you want to invest in controls
Energy savings, time savings, comfort issues, maintenance
• What pieces of equipment do you want to control?
• Staff has knowledge, skill, willingness to adopt new controls
• Adding controls does not necessarily imply getting a controls contractor involved. At what point to bring them in?
• Would you enable cruise control on a car that has an oil leak, clogged filters or engine knock?
• Would you want to add RTU controls to a unit that had a failed economizer or dented condensing coils?
What is the condition of existing equipment
Small Building Example for Good, Better, Best
• 5,006 ft2
• Existing Controls include light switches and two wall t-stats
• Typical Office Space
Small-Good
• Simple Switch replacement with occupancy
• Motion sensing
• Internet Connected thermostat
• Timers for exhaust fans
• This slide should be a layout of the building with the wall t-stats added and dimmer/occ sensors, and plug load controls, exhaust fans
Low Voltage Thermostat circa 1995
Mechanical Wall Switch
Functions of “Smart” Thermostats
Learning
• Learns your routines
• Understands how your business heats up or cools down
Alerts
• Will shut down heating/cooling system if smoke is sensed with compatible detectors.
Remote control
Staging
Small - Better
• Internet Connected thermostat with remote access, limited local control, global setpoints
• plus: basic trending, energy analysis, fault detection
• Daylight harvesting, zone control, building wide
• Motion sensing for exhaust fans
• This slide should be a layout of the building with the wall t-stats added and dimmer/occ sensors, and plug load controls, exhaust fans
• This slide should be a layout of the building with the wall t-stats added and dimmer/occ sensors, and plug load controls, exhaust fans
Example – Retail Store – Web Enabled Thermostat
• 13 small retail stores with manual wall thermostats
• Added web enabled thermostat allowing for supervisory control
• Savings ranged between 0% - 12%, average 4.6% for cooling, and 2.6% on heating ~ $450/yr
• Cost $800 - $900/thermostat
• Efficiency Vermont Incentive $150
• 1.5 year return on investment
Small - Best
• Connect HVAC and Lighting to DDC web-based controls
• Add energy savings controls such as:
• Supply fan VFD
• CO2 sensors
• Advanced economizer
• Occupancy Based Lighting
• Daylight Harvesting
Small Best
• Piezoelectric operation means no batteries, 120/277V, or low voltage wiring needed.
• Sensors mounted on fixtures make installation easy
Case Study – RTU Controls @ Efficiency Vermont What is a RTU Control?
• VFD on supply fan PLUS o Enhanced economizers o Fault diagnosis and detection o Demand control ventilation
Efficiency Vermont RTU Savings
• Existing constant volume RTU, 8 tons, 2 hp supply fan
• Added VFD to supply fan
• Cost $2,000 ($8,000 for unit with fault detection)
• Savings 65% of fan energy, 45% overall energy savings
• 4,100 KWh
Large Building Example for Good, Better, Best
• 67,000 ft2
• Existing Controls include simple DDC
• Large Warehouse Storage Area
• Office Space
• High security areas
• High occupancy across 2 shifts
Large – Good • Connected thermostats
• Temperature setback
• Timers on exhaust fans
• Occupancy sensors in office
• TLED replacement
• Utilize existing controls (equipment or DDC)
Large Better
• Packaged controls for major mechanical equipment (with energy savings)
• Utilize existing DDC to add control points and implement energy savings
• Advanced lighting controls connected to web enabled software (stand alone) including daylighting, occupancy, zone control – this would require new fixtures or retrofit kit
Packaged Cooling Tower Controls
Burner Controls
Case Study -
• Existing facility with DDC system controlling HVAC
• Efficiency Vermont discovered all 4 air handling units were operating 24/7
• Created an occupied/ unoccupied schedule in DDC
• Savings of more than $9,000 per year are expected from this $0 control change
• 150 high bay fixtures can cost up to $27k annually to run (@ 200W each and .17/kWh)
• Replacing with equivalent LEDs could lead to a reduction in energy cost by 80%. This isn’t even taking the cost of replacing bulbs and ballasts into consideration
• Additional investment in occupancy sensing reduces that remaining energy cost by 20%.
Large Best
• Full DDC control of heating and cooling systems
• Integrated lighting, HVAC and security system • Identifies personnel by their mobile device and allows them into
certain areas • Path tracking delivery insight into how physical space can be
better utilized
• Remote monitoring and trending with data analytics • Predict major equipment failure, automatically generate building
equipment health assessment
• Floorplan graphics make visualizing building performance easy
Benefits of a “Smart” Lighting System
• Variable color temperature of fixtures can increase productivity and inspire creativity in different spaces.
• Most of the time, little to no additional cost.
• Adjust light to individual needs.
• Energy Savings
• Reduced operational cost of replacing bulbs and ballasts
https://onlinemba.unc.edu/blog/how-lighting-affects-productivity/
Using Differentiation To Compensate for Solar Gain
y = 1.4388ln(x) - 0.3238
-1
0
1
2
3
4
5
6
0
0.2
0.4
0.6
0.8 1
1.2
1.4
1.6
1.8 2
2.2
2.4
2.6
2.8 3
3.2
3.4
3.6
3.8 4
4.2
4.4
4.6
4.8 5
Lig
ht
Level (l
ux)
Time
• Heating load is not equal to cooling load
• Two different modes for summer and winter • Set back heat in winter
• Remove heat from a space at a faster rate in summer
Using Differentiation To Compensate for Solar Gain
• Use single sensors to duplicate
• OA reset on multiple buildings can be done by reading a single OA sensor.
• Use connected lighting control to adjust lighting level campus-wide (with exception of egress) in a security event.
• Use saved trends to compare similar equipment performance.
• Save total troubleshooting by using DDC and asset database to decrease idle time.
Advantages of DDC for a Complex or Distributed Building Portfolio
• Save total troubleshooting by using DDC and asset database to decrease idle time.
• Reduce travel time between home planets
Advantages of DDC for a Complex or Distributed Building Portfolio
Managing the requirements to resources mismatch: Why invest $$ in building controls?
• Operations, especially HVAC is not usually particularly sexy, so need to minimize emotion for making resource decisions --> data!
Using Data to Communicate Importance of Controls Investment
“Operations staff is complaining about losing sleep worrying about the huge silver box on the roof. They called some reps and replacing it will cost us $60,000“
Another approach:
“We have a piece of equipment nearing the end if its life in Warehouse 5. As part of a $125,000 controls investment, we have an opportunity to lower energy and operational costs by $35,000 annually. Furthermore, using historical emergency maintenance data, we predict that the packaged analytics will save $5,000 annually. This area scores in the 95th percentile in MDI of our or assets, meaning a disruption in service to it would hamstring our critical business operations. You all have done the math - the simple payback on this investment is 3.5 years. What that number doesn’t represent is the improvement in productivity, improved safety and security, and the operations staff sleeping better at night
Importance of Persistence
• Things wear
• Heat transfer characteristics change
• Uses change
• Things break
• People tweak
• People forget/turnover
In a system, a process that occurs will tend to increase the total entropy of the universe.
2nd Law of Thermodynamics
Not enough staff? State of Vermont Executive Branch – 8,177.8 Full Time Equivalents (FTE) 1
1. State of Vermont Workforce Report FY2016