ATEM MODULE 3: CONTROLS A c c r e d i t e d T e x a s E n e r g y - PowerPoint PPT Presentation

ATEM MODULE 3: CONTROLS A c c r e d i t e d T e x a s E n e r g y M a n a g e r

System Types ❯ Manual ❯ Programmable thermostats ❯ Mechanical time clocks ❯ Electronic time clocks ❯ Pneumatic controls ❯ Networked thermostats ❯ Direct digital control (DDC) A c c re d i t e d Tex a s E n e rg y M a n a ge r

Pneumatic Control Systems ❯ Air compressor ❯ Piping & tubing ❯ Sensors ❯ Actuators A c c re d i t e d Tex a s E n e rg y M a n a ge r

DDC System Components ❯ Desktop or laptop computer ❯ Sensors -Operator workstation ❯ Data -Programming -Analog – variable -Network interface -Digital – 0 or 1/on-off/open-closed ❯ Controllers – executes control ❯ Network cabling logic based on inputs -Building -Local ❯ Communications interfaces A c c re d i t e d Tex a s E n e rg y M a n a ge r

DDC System Architecture Internet BC C C C e n e r g y m a n a g e m e n t p r o g r a m : f u n d a m e n t a l s a n d d e v e l o p m e n t

DDC Inputs & Outputs Temperature Valve open/close Control Outputs Sensor Inputs Pressure Damper Flow open/close Controller Humidity Motor off/on Motor status Indicator light Switch position Alarm e n e r g y m a n a g e m e n t p r o g r a m : f u n d a m e n t a l s a n d d e v e l o p m e n t

DDC System Functions ❯ Scheduling ❯ Monitoring -Normal work days ❯ Logging & trending -Events ❯ Diagnostics & troubleshooting -Weekends ❯ Alarming -Holidays ❯ Control strategies -Optimum start & stop -Demand limiting -Temperature resets A c c re d i t e d Tex a s E n e rg y M a n a ge r

DDC Protocols ❯ BACNet ❯ Tridium (Niagra) -Open protocol -Proprietary built on open standards -Developed by ASHRAE -Allows integration of diverse -Specifically for building equipment systems control ❯ LONTalk -Proprietary protocol -Developed by Echelon Corp. -Special micro-compressor chip required for communication A c c re d i t e d Tex a s E n e rg y M a n a ge r

Demand Control Ventilation ❯ Utilize in area w/ high occupancy levels ❯ Uses CO 2 levels to estimate occupancy ❯ Controls outside air flow w/ modulating dampers -Closed at zero occupancy (low CO 2 level) -Full open at maximum occupancy (high CO 2 level) A c c re d i t e d Tex a s E n e rg y M a n a ge r

Utilizing Economizers ❯ Supplies 100% outside air for cooling ❯ Compressors do not operate ❯ Takes advantage of mild outdoor conditions ❯ Control types -Dry bulb › Less humid climates › Temperature only -Enthalpy › More humid climates › Temperature & humidity A c c re d i t e d Tex a s E n e rg y M a n a ge r

Economizer Operation e n e r g y m a n a g e m e n t p r o g r a m : f u n d a m e n t a l s a n d d e v e l o p m e n t

Setpoints ❯ Occupied -Occupant comfort -Energy savings -Cooling costs rise 1.5% for each degree below 72 º -Heating costs rise 1% for each degree above 68 º ❯ Unoccupied -Energy savings -Prevent building damage -Use instead of turning systems off A c c re d i t e d Tex a s E n e rg y M a n a ge r

Control Strategies ❯ Demand limiting -Demand limit setting -Loads shed when setting reached -Reduces peak demand & utility charges ❯ Optimal startup -Heating or cooling started before occupied time -Setpoint reached at scheduled occupied time ❯ Optimum stop -Heating or cooling setback while facilities occupied - Building allowed to “coast” A c c re d i t e d Tex a s E n e rg y M a n a ge r

More Control Strategies ❯ Supply air temperature reset -Based on return air or outside air temperature -Reduces amount of reheat during cooling ❯ Chilled water temperature reset -Raise temperature of chilled water -Based on outdoor temperature & humidity -Caution not to raise temperature too much in humid conditions ❯ Condenser water temperature reset - Decrease temperature of water leaving cooling tower - Increases chiller efficiency - Reduces chiller capacity A c c re d i t e d Tex a s E n e rg y M a n a ge r

Sample Display Screen e n e r g y m a n a g e m e n t p r o g r a m : f u n d a m e n t a l s a n d d e v e l o p m e n t

Sample Display Screen e n e r g y m a n a g e m e n t p r o g r a m : f u n d a m e n t a l s a n d d e v e l o p m e n t

questions Ashley Williams, MCRP & ATEM ❯ Texas Energy Managers Association ❯ Director of Curriculum and Certification ❯ awilliams@texasema.org Texas Energy Managers Association ❯ www.texasema.org e n e r g y m a n a g e m e n t p r o g r a m : f u n d a m e n t a l s a n d d e v e l o p m e n t