Why Invest in Building Controls? - Efficiency Vermont

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

Building Size and Equipment Complexity

LARGE SMALL



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)

Existing Controls and Equipment Simple Vs Complex



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



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

Fan Coil Unit Under Window Unoccupied

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

Low $$ Plug n Play

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



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

Daylight Harvesting

Advanced lighting as described by occupant

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

Insert photo of DDC showing setpoint

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

Demand Controlled Ventilation

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)

Utilize existing DDC to allow for further fine tuning of schedules and optimal start stop

Example – Enable Boiler Controls

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

VFD Tower Controls Burner Controls Sensors Fixtures

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/

Design Verification Case Study

Using Differentiation To Compensate for Solar Gain

y = 1.4388ln(x) - 0.3238

-1

0

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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!

US Navy - Quantifying

Risk, Prioritizing

Maintenance

MDI Survey Results

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

Agency of Administration – 638 FTE1


Buildings and General Services – 324 FTE1


Energy Office – 4 Employees

Why Invest in Building Controls? - Efficiency Vermont

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