Tag Archives: occupancy sensors

GSA building in Foggy Bottom

GSA building in Foggy Bottom by Herr Vebah on Flickr

Last week, the The U.S. General Services Administration released two new reports regarding innovative building technologies that could help the government use less energy if implemented. They worked with the Department of Energy’s National Laboratories to test the viability of two new key innovations. “This innovative program is another example of GSA leading the way for the federal government,” said Dorothy Robyn, Commissioner of GSA’s Public Buildings Service. “By testing the effectiveness of these technologies, GSA is finding new ways that federal buildings across the nation can save both energy and taxpayer dollars.”

Responsive Lighting

The first of these technologies being evaluated was a package that includes workstation-specific lighting system, dimmable ballasts, occupancy sensors at each luminaire, and controls. There are many government service agencies that work very long hours and could see substantial savings as a result. The GSA notes:

The Responsive Lighting study evaluated the performance of new workstation-specific lighting systems. The study was conducted in five federal buildings in California and Nevada that represented a diverse set of agencies, occupancy patterns, work styles, and lighting. Results showed energy savings that ranged  from approximately 27 to 63 percent over baseline conditions depending on the work space’s normal use. Lighting accounts for 39 percent of electricity costs in office buildings.

Plug Load Control

About 25% of the electrical load in a typical modern office comes from the various peripherals plugged into outlets, like printers, computers and copy machines. The GSA worked with a team from the National Renewable Energy Laboratory (NREL) to test some smart power strips that included three different load-reduction techniques; schedule timer control, load-sensing control, and a combination of the two.

Results showed the APS’ schedule based capability  to be highly effective, reducing plug loads at workstations by 26 percent, and nearly 50 percent in kitchens and printer rooms. This technology could significantly reduce costs, as plug-loads account for  roughly 25 percent of total electricity consumed within office buildings.

GSA owns and leases 9,600 buildings across the country and has the real estate portfolio needed to broadly test and install these technologies. A solicitation for submissions of building technologies to be tested under the GSA’s Green Proving Ground program in FY 2013 will be posted at the agency’s website in the coming weeks.

IdeaThis list of energy efficiency measures and projects is a great place to start in determining which activity will have the greatest impact on your building, with your tenants and on your operational cash flow:

  • Building envelope improvement
    • Weather/infiltration sealing
    • Increased insulation
    • High performance window replacement
    • Low emissivity reflective window film (to reduce unwanted solar gain in the summer and increase the R-value of windows in the winter)
  • Lighting
    • “Delamping,” i.e. permanently turning off/disconnecting unneeded light fixtures
    • “Relamping,” i.e. replacing inefficient light fixtures or lamps with high efficiency fixtures/lamps
      • Convert T-12 fixtures/lamps to T-8 or T-5
      • Relamp 32 watt T-8 lamps with 28 watt T-8
      • Eliminate incandescent bulbs
      • Convert all exit lighting to LEDs or switch to photoluminescent signs that require no electricity
      • Beware of retrofitting with indirect lighting – while classy looking it may require more fixtures and more wattage
    • Increase reliance on task lighting in order to decrease general illumination without adversely affecting productivity
    • Improve lighting controls
      • Occupancy sensors
      • Timers (stand alone or energy management system or EMS-interfaced)
      • Daylight harvesting sensors and controls including simple photocells
    • Convert outdoor lighting to high pressure sodium
    • Eliminate/reduce outdoor decorative lighting
    • Consider LEDs for general indoor and outdoor illumination (the technology is almost there)
    • Consider outdoor solar powered-LED light fixtures (this technology is also almost there)
    • Require white or off-white wall paints for maximum light reflectivity so adequate lighting levels can be achieved with minimum lighting wattage
    • When renovating spaces, design new lighting for less than 1.0 watts per square foot
  • Boilers
    • Replace old boilers with new high efficiency boilers
    • Do not oversize replacement boilers
    • Retrofit boilers with variable flame burners
    • Consider multiple high efficiency modular boilers to improve efficiency by better matching hot water heating loads
    • Consider replacing boilers with cogenerators (which also produce electricity)
    • Control boiler output water temperature with outside air temp reset so boiler does not need to heat water hotter than necessary
    • Retrofit boilers with flue gas/stack heat recovery
  • Chillers
    • Replace old chillers with new high efficiency chillers whose efficiency curve best matches your load profile
    • Do not oversize replacement chillers
    • Operate at peak efficiency (by adjusting water flow, load, condenser/evaporator water temps, etc.)
    • Replace old cooling towers with new high efficiency towers
  • Air conditioning
    • Replace older AC equipment with maximum efficiency models
    • Discontinue use of inefficient window units
    • Reduce AC operating hours
    • Turn off reheats and stop controlling humidity levels during the cooling season
    • Clean cooling coils on a regular basis
    • Maximize use of “free cooling” with economizer cycle
    • Use open windows and passive cooling when mechanical air conditioning is not needed
    • Close windows when air conditioning is in operation
    • In dry climates consider evaporative cooling
    • In humid areas consider desiccant cooling
  • Temperature control
    • Reduce temperature settings in winter
    • Increase temperature settings in summer
    • Maximize night, weekend and holiday temperature setbacks
    • Install tamper proof or remote thermostats
    • Control space temp remotely by EMS
    • If occupant controlled thermostats are required, then limit range of adjustment to ensure campus temperature policy compliance
  • Motors, fans and pumps
    • Adjust operating schedule to minimize run hours (review and update periodically)
    • Replace old motors, pumps, and air handling units with high efficiency
    • Control motors serving fans and pumps with variable speed drives (VSDs)
    • Operate VSDs at maximum acceptable turn-down; vary by time of day and occupancy; also vary by season
    • Convert constant volume fan system to variable air volume
    • Reduce outside air volume during morning warm-up cycle and where/whenever possible through damper settings and demand control ventilation
    • Reduce needless pumping by eliminating three-way by-pass valves
  • Laboratory Ventilation and Fume Hoods
    • Switch to a “green chemistry” teaching program that doesn’t require fume hoods
    • Turn off 100% outside air ventilating systems whenever possible, e.g. in teaching labs whenever classes are not in session; shut down or slow down related supply fans
    • Decommission/remove unneeded fume hoods and reduce fan system outside air volume
    • Eliminate unneeded fume hoods by using ventilated storage cabinets instead of hoods for chemical storage
    • Retrofit constant volume fume hood ventilation systems to variable air volume
    • Retrofit conventional fume hoods with low-flow hoods and reduce outside air volumes
    • Retrofit these systems with heat recovery
  • Heat recovery
    • Run around loops
    • Heat wheels
    • Heat pipes
    • Desiccant wheels
    • Air-to-air heat exchangers
    • Install heat recovery
  • Energy Management Systems (EMS)
    • Switch to direct digital control (DDC) systems
    • Purchase EMS systems which are easy to program (so programming capabilities will be fully utilized by facilities staff)
    • Utilize and optimize use of EMS energy conservation programs, e.g.
      • Optimal start/stop
      • Night setback
      • Demand shedding
      • Remote programmed lighting control
  • Fuel Switching
    • Consider converting electric space and water heating to natural gas
  • Energy Intelligence & feedback systems
    • Accessible display units that show energy use and savings can have dramatic results in energy use behaviors
USACE, Sembach develop net-zero energy master plan

USACE, Sembach develop net-zero energy master plan by USACE Europe District on Flickr

Building energy audits can be performed on commercial and industrial buildings to assess the amount of energy currently being used and assist in prioritizing and implementing energy-efficiency projects. Energy audits use a variety of techniques to evaluate energy efficiency and identify potential efficiency improvements to lower utility bills and increase comfort. Energy Star rating is just one method of establishing a comparative baseline of the energy usage of a building. Energy audits will assist building owners and property managers in identifying ways to help lower operating costs and create a more competitive position for their building in the real estate market.

Energy audits can be obtained at no cost to the building owner and at a minimum should include a review of the building envelope and building operations.

Typical energy audit reports will include similar recommendations in the following areas:

  • Building Envelope and Building Operations
  • Lighting Systems
    • Occupancy sensors for lighting in amenity areas
  • Heating and Cooling
    • Scheduled start and stop of HVAC equipment and lighting
  • Water Heating
    • Reset boiler hot water temperatures based upon outside air temp
    • Lower domestic hot water temp to 120 degrees
  • Energy Management Systems and Controls
    • Repair/ Replace defective zone control valves
    • Controls to lock out central cooling below 50 degrees
    • Controls to lock out central heating above 65 degrees
  • Set space temperatures during unoccupied times up to 85 degrees/ set back to 65 degrees at night
  • Annual Maintenance
    • Changing filters, cleaning coils and cleaning tubes/duct-work
  • Heat Recovery Operations

Sample Energy Audit Recommendations

Low Cost/ No-Cost Energy Conservation Measures

  • Install Programmable thermostats
  • Insulate interior hot water pipes
  • Install photocell control of parking lot and exterior lighting
  • Global Control for computer monitors “off” after 15 minutes of inactivity or at night

Retrofit or Upgrade at next replacement cycle

  • Evaluate potential savings for alternate Power Systems – Variable Frequency Drives
  • Install low flow faucets, and toilets
  • Install higher efficiency heating or cooling systems
  • Increase roof insulation
  • Evaluate window replacement
  • Replace higher efficiency lighting in common areas, exit lighting and stairwell lighting

Higher efficiency lighting in room areas, especially to replace incandescent bulbs

Get Going

  • Take advantage of DOE’s Energy Star – energy benchmarking software to easily get started and help you establish priorities.
  • Contact a deregulated energy broker in your area and request a free energy audit
  • Contact your local utility company and request a free energy audit
  • Review, prioritize and assign energy conservation measures and energy efficiency measures to ensure all high impact ROI and Low Cost projects are assigned and implemented first.

Contact your local energy broker to provide a list of all available energy rebates and tax incentives.