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

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Dec 12, 2022 504 likes •714 views

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

SLIDE 1

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

SLIDE 2

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

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Pneumatic Control Systems

A c c re d i t e d Tex a s E n e rg y M a n a ge r

❯Air compressor ❯Piping & tubing ❯Sensors ❯Actuators

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DDC System Components

❯Desktop or laptop computer

Operator workstation
Programming
Network interface

❯Controllers – executes control

logic based on inputs

Building
Local

❯Communications interfaces ❯Sensors ❯Data

Analog – variable
Digital – 0 or 1/on-off/open-closed

❯Network cabling

A c c re d i t e d Tex a s E n e rg y M a n a ge r

SLIDE 5

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 Architecture

BC C C C Internet

SLIDE 6

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

Controller

Control Outputs Sensor Inputs Valve open/close Damper

pen/close

Motor off/on Indicator light Alarm Temperature Pressure Flow Humidity Motor status Switch position

SLIDE 7

DDC System Functions

❯Scheduling

Normal work days
Events
Weekends
Holidays

❯Control strategies

Optimum start & stop
Demand limiting
Temperature resets

❯Monitoring ❯Logging & trending ❯Diagnostics & troubleshooting ❯Alarming

A c c re d i t e d Tex a s E n e rg y M a n a ge r

SLIDE 8

DDC Protocols

❯BACNet

Open protocol
Developed by ASHRAE
Specifically for building equipment

control

❯LONTalk

Proprietary protocol
Developed by Echelon Corp.
Special micro-compressor chip

required for communication

❯Tridium (Niagra)

Proprietary built on open

standards

Allows integration of diverse

systems

A c c re d i t e d Tex a s E n e rg y M a n a ge r

SLIDE 9

Demand Control Ventilation

❯Utilize in area w/ high occupancy levels ❯Uses CO2 levels to estimate occupancy ❯Controls outside air flow w/ modulating dampers

Closed at zero occupancy (low CO2 level)
Full open at maximum occupancy (high CO2 level)

A c c re d i t e d Tex a s E n e rg y M a n a ge r

SLIDE 10

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

SLIDE 11

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

Economizer Operation

SLIDE 12

Setpoints

A c c re d i t e d Tex a s E n e rg y M a n a ge r

❯Occupied

Occupant comfort
Energy savings
Cooling costs rise 1.5% for each

degree below 72º

Heating costs rise 1% for each

degree above 68º

❯Unoccupied

Energy savings
Prevent building damage
Use instead of turning systems off

SLIDE 13

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

SLIDE 14

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

SLIDE 15

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

SLIDE 16

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

SLIDE 17

Ashley Williams, MCRP & ATEM

❯ Texas Energy Managers Association ❯ Director of Curriculum and Certification ❯ awilliams@texasema.org

questions

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

Texas Energy Managers Association

❯ www.texasema.org

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