Provide services only when and where required at the optimum levels utilizing efficient energy conversion
Provide services only when needed • Turning stuff off when it’s not required Lights Boilers Cooling towers Air handling units Chillers HVAC systems Pumps Computers and monitors Machinery Compressed air
Providing services on demand • Tie cooling towers operation to the equipment it supports • Control HVAC fans by monitoring static air pressure • Vary lighting levels for current work requirement • Occupancy sensors • http://lbenergymanagement.web.boeing.com/db/BoeingLB/HVAC/Bldg_802/FloorPlans/Map_802_1WNE_Maint • Limit occupied schedules and allow occupants to override for after hours work http://lbenergymanagement.web.boeing.com/db/BoeingLB/Lighting/Bldg_41A/Floor3/Floorplan • Control boilers by monitoring demand • http://lbenergymanagement.web.boeing.com/db/BoeingLB/HVAC/Bldg_81/ChilledWater/Graphic
Provide services at minimum required levels • Lighting • Hot water temperature • Chilled water temperature • HVAC cold deck temperature (supply air reset) • Compressed air • Space temperatures • Fan speed (reduce using variable frequency drives) • Task lighting • Outside air (ventilation) control by using CO2 sensors for theaters, cafeterias • Off hours ventilation air, reset requirements for after hours, weekends and holidays
Using equipment with efficient energy transfer • Lighting • Radiant heating in lieu of convection heating • Compressors • Boilers • HVAC systems • Motors • Compressed air systems • Computer monitors (LCD vs. CRT) • Self luminous exit signs • Electric fans vs. Copus units • Direct drive vs. belt drive
Using the environment to save energy • Outside air for cooling / heating when practical (economizer cycle) • Sunlight when practical (Daylight Harvesting) • Reflective floors to increase light level • Solar power
Reduce energy loss • Insulation • Reduce loss through piping runs (distributed systems) • Clean lighting lenses, fixtures • Air leaks (Air Leaks in a typical plant will make up approximately 20-30% of the total compressed air system demand). A single ¼” leak costs approximately $8,000 per year. • Window glazing • Filters (condition based vs. scheduled) • Running equipment outside of their efficient ranges (motors, compressors, chillers) • Adjacent HVAC zones fighting each other (1 in cooling and 1 in heating) • Reheating air in HVAC systems
Load shifting • Chilled water storage • Does it save energy? • No, but it significantly reduces costs by shifting energy use to off-peak times
How does the energy team function? • The team: • Brainstorms ideas to reduce energy – solicits ideas from co-workers • Performs estimates for energy savings projections and implementation costs • Eliminates ideas with poor business cases • Totem poles remaining projects prioritizing projects with the highest return on investment, projects with the greatest energy saving potential and projects with low costs for implementation
Energy team continued • Creates business cases for top candidates • Presents our recommendations to management • Implements the projects • Tracks energy and dollar savings • Continues down the list using the same process while constantly looking for new savings opportunities • Performs energy audits
Questions • Does an energy management system save money? • Does an energy management system provide maximum efficiency on the day it’s commissioned? • Does an energy management system reduce the requirement for maintenance? • When is it a disadvantage to install economizer? • When should we do load shedding? • Are all control strategies created equal? Examples - supply air temperature reset, economizer
Answers • Does an energy management system save energy? • No, it’s the control strategies that are implemented with the energy management system that saves energy. • Does an energy management system provide maximum efficiency on the day it’s commissioned? • No, typically the integrator will not spend the time to tweak the system for maximum efficiency.
Answers continued • Does an energy management system reduce the requirement for maintenance? • No, energy management systems can significantly reduce the time to troubleshoot problems butwith additional controls to maximize energy savings it becomes even more critical to maintain the systems properly. • When is it a disadvantage to install economizer? • When it’s not maintained.
Answers continued • When should we do load shedding? • All the time • Examples daylight harvesting, cold water, ice storage, control outside (ventilation) air by using CO2 sensors for theaters, cafeterias, ice skating rinks, bowling alleys • Are all control strategies created equal? Examples supply air temperature reset, economizer • No
Are all control strategies created equal? Example 1 • Supply air temperature reset using return air temp • Supply air temp reset using outside air temp • Supply air temp reset using average VAV box demand • Supply air temp reset using highest VAV box demand • Supply air temp reset using average or highest VAV box demand (selectable) • Adding humidity control
Are all control strategies created equal? Example 2 • Economizer (dry bulb) • Economizer utilizing enthalpy • Economizer using enthalpy and humidity control • adding low temp lockout • adding high humidity lockout
Look for low hanging fruit • Turning on and off equipment that runs constantly. Scheduling the equipment for 9 hours a day operation Monday through Friday reduces energy usage by 74%. In addition it extends the life of the equipment and reduces maintenance costs.