Overly complex and fully automatic control systems in high performance commercial buildings often lead to a disconnect in design intent and realizing net zero in actual operations. To address this disconnect, we have developed a high performance building control concept that simplifies control and engages occupants in reaching net zero operations. This slide deck reviews the details of this concept as applied in our own net zero projects at NREL, and proposes additional Occupant Engaged control concepts.

1. A High Performance Building
Control Concept for Engaging
Occupants as Users of Efficiency
Controls
Shanti Pless, Jen Scheib, Paul Torcellini: NREL
Tom Hootman: MKK Engineers
October 2014

2. Occupant Engaged: A High Performance
Building Control Concept for Engaging
Occupants as Users of Efficiency Controls
Shanti Pless, Jen Scheib, Paul Torcellini, NREL
• As was recently highlighted in recent Pathways to ZNE Buildings in California,
understanding occupant interactions with high performance building controls can
lead to further energy savings opportunities. In general, the building controls
industry has trended toward more automation for energy savings, resulting in
complex systems that have removed occupants from engaging in better controls.
In this paper, we propose a solution for a simpler controls philosophy that engages
occupants, which can help lead to lower energy use and more satisfied users. This
control concept, which we have coined Occupant Engaged, is based on the idea
that control systems can be designed and operated to require occupant
engagement to take a system from the off to occupied state. And then the
system’s automation will turn off or go to unoccupied state if the occupant
“forgets” to turn off the system. This paper documents specific lighting control,
plug load controls, glare controls, and HVAC control implementation successes of
the Occupant Engaged controls. In one case, savings from Occupant Engaged
lighting controls in a partially daylit break room saved 70% in lighting energy use as
compared to a typical occupancy sensor fully automatic lighting control system. In
general, we have found occupants will engage with their systems, and energy
savings from these simpler controls are greater than fully automatic controls.

3. CONTROL

7. Automation vs. Manual Control
• “In part due to the unpredictability of user behavior,
the building industry overall has embraced automation
as a means of reducing energy waste
• However, development and evaluation of automation
has not adequately accounted for building users’ desire
for control or the potential energy savings from manual
versus automated control
• Better integrating the human dimension in designing
and selecting automation can help lead to lower
energy use as well as more satisfied users”
Road to ZNE: Mapping Pathways to ZNE Buildings in California.
Heschong Mahone Group, Inc.

9. People in Buildings…
• “will adapt the building, systems, controls and features
to their needs and wants. This is not to say that they
will adversely affect the carefully crafted building and
system designs, but they will make things work for
them if they can.
• can and do adapt to new designs and learn how to use
buildings”
“Therefore, strategies for supporting occupants on how to
maximize their building’s energy efficiency attributes
should be developed”
Road to ZNE: Mapping Pathways to ZNE Buildings in California.
Heschong Mahone Group, Inc.

10. CABA Zero Net Energy Building Controls
Occupants are Operators
but Default Settings Need
to be the Backup. Provide
occupants with energy use
engagement and control
access with a ‘hybrid’
system that returns
controls to default settings
and “Off”.
http://www.caba.org/CABA/Research/Zero-Net-Energy-
Buildings.aspx

11. A Solution: Occupant Engaged
• A control philosophy for engaging occupants in high
performance buildings operations as active users
• Requires occupant engagement to take a system from
off to occupied state
– Default mode is maximum efficiency mode
• off or setback
– No automatic ON
– Occupant engages control to turn on if service needed
• Intelligence to turn off or go to unoccupied state if occupant
“forgets” to turn off
– MUST have simple local occupant engagement interface
• On/off switches the best

12. Occupant Engaged:
Current Applications at NREL
• Vacancy Sensors for Lighting
– Manual ON, manual OFF, with automatic dim and OFF
when vacancy sensed
• Timer-OFF controls for plug loads with manual ON
• Local glare control
– Local manual tint of electrochromics, manual clear with
automatic timed clear
• Operable Windows for Natural Ventilation
• Local USB powered desktop fan
– Turns off when computer goes to sleep

13. Occupant Engaged:
Applications in Development or Proposed
• Shades with Occupant Engaged controls
• HVAC Occupant Enabled
– Local ventilation
– Local heating/cooling
• Real time Personal Energy Efficiency Feedback
System
• Vacancy sensor LED task lights
• USB desktop hub with vacancy sensor

14. Occupant Engaged Development at
NREL
• Started with large scale vacancy sensors
application in all daylit spaces in RSF
– Most successful in enclosed offices, conference
rooms, and intermittently occupied daylit zones
such as corridors and break rooms
– Vacancy sensors in daylit break rooms resulted in
70% energy savings over a occupancy sensor
• Measured savings by logging occupancy and lighting
energy use
– Similar to current 90.1 and Title 24 Vacancy
Sensor lighting control requirements

15. Occupant Engaged Development at
NREL
• Next application is plug loads
– Has become the standard for office space in 2013
• Electrochromics in ESIF
– Local zone control for south windows
In general, we find that occupants will engage when they
are given the chance and really need the service…
– But are often indifferent and don’t really need it as much
as we thought
• Occupants turn on open office lights when daylighting is providing
less than 10 fc
Expanded comfort savings are realized in temperature,
local air movement, light levels, and glare control when
occupants have local control over these conditions

16. – Lighting control in conference rooms
• First press of ON button in partially daylit conference
rooms with native dimming capability should bring
lights on to a dimmed state (35%)
• User has to hold dim UP button to get full lighting
output if they really want it…
• Vacancy automatically shuts off after space becomes unoccupied
– We see this as a promising application for open
office Personal Lighting Systems as well
Additional examples in Use- Lighting

21. • Occupant Engaged Task Light
– integral vacancy sensor to turn off if not turned off
manually
• Not an occupancy sensor task light!
– USB powered to match DC power supply with DC load?
Does not yet exist…can we invent this?
Future development needs- Lighting

23. • Manual on button for power strip with manual
off and timer off after 10 or 11 hours
• Controls task light and other office space loads
afterhours
• Tie as many loads to USB ports that turn off when
computer goes into automatic sleep mode
• Task lights (does a desktop USB powered task light exist?)
• USB fans
• Chargers
• Monitors
• USB hub with vacancy sensor
• Invent this too…
Examples in Use- Plug Loads

25. GLARE CONTROL

26. – Glare control with Electrochromics
• Manual window tint switch for local
zones, with automatic timer clear after
2 hours
– Glare control with shades – in
development
• Manual roller shades down, with
manual up and with an automatic up
timer for 4 hours (or very slow
automatic raise over 4 hours)
– Need to develop this…
Examples in Use

29. HVAC Applications
• USB powered desk top fans
– Controlled with USB power in laptops
• Building goes into “Passive” mode
– Requires occupants to open windows/turn on local fans/air to
meet local comfort
• Other possible control systems
– Lab air with manual occupied switch
– Turn off HVAC when OA conditions are ok for natural ventilation
– Local/Personal HVAC control system for personal heat pump
• Similar to car climate control for an office space – invent this too

31. OE Natural Ventilation with Windows?
• Manual Open window
• Manual Close window
– Easy to forget, even for the most educated
occupants
• Automatic close window
– To be developed…similar to automatic window
closers
– Push out charges battery with regen motor
• Small PV panel to provide additional battery capacity
– OR- Push out wind-up mechanical spring slowly
pulls window back
– window to close after 4 hours of open
• Adjustable timer
– No wiring and simple, but assures manual
windows close at night

32. Occupant Education?
MUST have simple occupant engagement controls!
• You have light switches- you can use them
• If you open a window – close it
• If you are stuffy- open your window
• If you have a local glare issue, pull your shade
• Turn on your power strip in the morning
• Opt-out of efficiency default mode into occupied/energy use mode
• Occupants have to and will “figure it out”
• “Hassle Factor” of controls for efficiency gains
– We would watch the same channel on TV all the time if we didn’t have
a remote control…
– Actual office lighting levels measured before occupants engage to turn
on open office ambient lights are 10 FC and below

34. Feedback of Occupant Engaged
Controls
• Blink warn when timer is up
• Occ sensor will turn lights back on for 10
seconds after vacancy is detected
– Operates as an Occ sensor to account for false off
– After 10 sec, manual on is required
• Returns to Vacancy sensor

35. Occupants need better feedback
– Building owners and operators lack a fundamental
active element when managing the efficient,
sustained operation of their buildings: the Occupant
– NREL has installed outlet-level plug load metering
equipment at the workstations of 200 employees
– Data from these plug load meters can be used to:
• Inform ESIF occupants of their personal energy efficiency
performance
• Incentivize energy saving behavior (leveraging the NREL
Building Agent app)

36. State-of-the-art options for plug load metering and control:

37. Occupants Engaged with Real-time Personal
Efficiency Score
Missing Link:
Provide Feedback
to Occupants
Technologies Deployed in the ESIF
• Feed data from plug load
meters into the
Building Agent App
• Provide occupants with data
to inform competitions and
incentivize good behavior
• Incentives could include:
• An “Energy Saver of the
Month” parking space
• “Group Energy Saver of
the Month” ice cream
social
• Gift cards

38. Technical Description of Proposed Work:
Mock Up of Occupant Feedback
Occupants could be shown how they compare to their anonymous neighbors

39. Technical Description of Proposed Work:
Mock Up of Occupant Feedback Continued
Occupants could be shown their real-time (and historical) energy consumption with
simple visualizations. Performance will be linked to energy saving tips.

41. The Building Agent
app enables
occupants to
quantify and
communicate their
comfort levels to
the building.

42. Future Work with OE
• Continue development of OE Task light
• Continue development of OE Window shade
• Continue development of OE Personal
heating/cooling solutions
• Continue development of OE USB power hub
• Continue development of OE window return
• Identify development partners to bring OE
products to market for future ZEB projects!

43. References:
• California Net Zero Roadmap
– http://www.energydataweb.com/cpucFiles/pdaDocs/899/Road
%20to%20ZNE%20FINAL%20Report_withAppendices.pdf
• Henze, G. P.; Pless, S.; Petersen, A.; Long, N.; Scambos, A.
T. (2014). Control Limits for Building Energy End Use Based
on Engineering Judgment, Frequency Analysis, and Quantile
Regression. 92 pp.; NREL Report No. TP-5500-60020.
http://www.nrel.gov/docs/fy14osti/60020.pdf
• http://www.nrel.gov/continuum/energy_integration/living_
laboratory.cfm
• http://www.sciencedirect.com/science/article/pii/S036013
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