KNX city Part 4: Energy management

KNX cityPart 4: Energy management

KNX Association International Page No. 222 April 2023

KNX: The worldwide STANDARD for home & building control

Definition of Energy efficiency

…in terms of the building„The objective of energy efficiency in the building is to save all forms of energy which are brought to the building from the outside by energy carriers such as gas, oil, electricity and water.“

… in terms of cities„ The objective of energy efficiency in cities is to save primary-energy such as fossil energy sources“

…in terms of „power supplies“„The objective of energy efficiency in power supplies is to reduce the electrical energy harvest from fossil energy sources and to increase the energy harvest from renewable energies“



Field of applications in the buildingExamples:

Commercial buildings:• Avoiding of heat losses occuring by opening windows over weekends• Avoiding heat losses by KNX heat and air conditioning control• Saving electrical energy by light control via presence-detection• Saving electrical energy by light-intensity and day-light control• …

Domestic homes• Saving energy by visualization of actual and total energy consumptions.• Saving energy by heat- and and air-conditioning controls• Saving energy by louver-controls (avoiding over overheating)• Comfort Aspects• New applications: Demand Response, Demand Side Management• …



KNX solutionsClassic fields of application

KNX offers total building controls• Lighting• Blinds & shutters• Security systems• Energy management• HVAC Systems• Monitoring systems• Remote control• Metering• Audio/Video• White goods

How to realize an energy management?



KNX control Systems

Controller• A controlller adapts an „actual value“ to a given „setpoint value“ and

keeps the „setpoint value“ without a deviation between both values• Example: A heating controller shall operate the heating in a way, that the

room temperature contains 23°C Control and metering task

• The „actual value“ must be measured with a „sensor“ • The controller proceeds the deviation and controls an „actuator“• The „actuator“ starts an action• Example: A KNX thermostat (controller) measures the room temperature

with a KNX temperature sensor and controls a valve of the heating system with a KNX electronic actuator



KNX Open-loop-control systems

Open loop Controller• A controller changes the „actual value“ in dependence of an input value

without getting a feedback about the real changes of the actual value• Example: A switching actuator is controlled in dependence of a

presence-detector Control and metering task

• Sometimes the setpoint value is set proportional to a measured value• Example: The angle of a louver is controlled in dependence of the sun

light. The sun light is measured by a weather-station. The setpoint value is set by a fixed table which describes the relation between angle and sun light.

Smart metering is a precondition Only the interaction between metering and actuators can

realize an energy management



Smart MeteringSmart Metering as a precondition for energy management



KNX solutionsExample: Open-loop light control

Presence-detectors detect if persons are present in the room• Yes: lights will be switched on• No: lights will be switched of

Application is often used for restrooms in commercial buildings

Electrical Energy can be saved



KNX solutionsExample: Open-loop light Control



KNX solutionsExample: Open-loop blinds & shutters control

Shutter-angle can be controlled in dependence of the position of the sun

Application is often used in Domestic Homes

Energy of systems for air conditioning can be saved



KNX solutionsExample: Open-loop blinds & shutters control



Cascaded heat control:Example: HVAC control

Cascaded control of a floor heater and an air conditioning system

The thermostat measures the actual temperature and adapts the room temperature to the setpoint temperature

Thermal energy can be saved



Cascaded heat control:Example Control-System: HVAC Control

Advantages:• One thermostat controls two heat devices• More than one control panel can be used for setting the setpoint

temperature of the thermostat• The cascaded control balances the slow thermal behavior of the floor

heater with a fast thermal behavior of the air conditioning system

Both thermal systems don‘t control against each other

The control of several thermal systems such as floor heaters, heatpumps, etc. is with KNX possible



Demand Side Management

Definition of Demand Side Management• „Demand Side Management describes the process to change the

energy demand of customers by incentives in order to get a better coverage of the energy generation“

• KNX can help by adapting loads



Demand Side Management:Control

The implementation with KNX is possible



KNX Energy Management solutions

More solutions can be found in:



Contact

Lutz [email protected]

KNX Association Brussels

mailto:[email protected]

mailto:[email protected]

Documents

KNX city Part 4: Energy management