The design outdoor temperature is location-specific. For Vienna (Austria), it is \u201313\u00b0C per \u00d6NORM EN 12831<\/strong>. For Munich (Germany), it is \u201312\u00b0C per DIN EN 12831<\/strong>. For Zurich (Switzerland), it is \u201310\u00b0C per SIA 384.201<\/strong>. iDM heat pump controllers are pre-configured with regional default values that must be verified and adjusted for each site.<\/p>\nWeather-Compensated Control (Witterungsgef\u00fchrte Regelung)<\/h3>\n
Definition:<\/strong> Weather-compensated control continuously adjusts the flow temperature setpoint based on real-time outdoor temperature measurements.<\/p>\nPurpose:<\/strong> It prevents the system from running at maximum flow temperature when outdoor conditions are mild, reducing energy consumption across partial-load seasons.<\/p>\nBenefits:<\/strong><\/p>\n\n- Reduces annual heat pump energy consumption by 10\u201320% compared to fixed setpoint control<\/li>\n
- Extends compressor operating hours at low, efficient load levels<\/li>\n
- Reduces thermal stress on heat emitters and pipework<\/li>\n<\/ul>\n
Practical Application:<\/strong><\/p>\nAn outdoor temperature sensor must be installed on a north-facing, shaded wall \u2014 free from direct sunlight, ground radiation, and exhaust air influence. The iDM Navigator 2.0 control unit integrates outdoor sensor readings every 60 seconds and recalculates the flow temperature setpoint dynamically.<\/p>\n
Flow and Return Temperature Management<\/h3>\n
Definition:<\/strong> Flow temperature (Vorlauftemperatur) is the temperature of water leaving the heat pump toward the heat emitters. Return temperature (R\u00fccklauftemperatur) is the temperature of water returning from the circuit to the heat pump.<\/p>\nPurpose:<\/strong> The spread between flow and return temperature (\u0394T) determines the rate of heat transfer. Correct \u0394T ensures efficient heat distribution and prevents low-load compressor cycling.<\/p>\nBenefits:<\/strong><\/p>\n\n- Optimises heat transfer across all emission systems<\/li>\n
- Prevents condenser overheating and high-pressure faults<\/li>\n
- Supports minimum flow rate requirements defined by the heat pump manufacturer<\/li>\n<\/ul>\n
Configuration Steps:<\/strong><\/p>\n\n- Set minimum and maximum flow temperature limits<\/li>\n
- Define the design \u0394T (typically 5 K for underfloor, 10 K for radiators)<\/li>\n
- Configure flow rate via variable-speed pump settings<\/li>\n
- Verify return temperature sensor calibration against a calibrated reference thermometer<\/li>\n<\/ol>\n
Domestic Hot Water (DHW) Configuration (Warmwasserbereitung)<\/h3>\n
Definition:<\/strong> DHW configuration defines the operating schedule, target temperatures, and priority rules for domestic hot water production within the heat pump system.<\/p>\nPurpose:<\/strong> It ensures hot water is available at the correct temperature, at the right times, without compromising space heating comfort or energy efficiency.<\/p>\nBenefits:<\/strong><\/p>\n\n- Reduces standby energy losses through intelligent scheduling<\/li>\n
- Prevents legionella growth through thermal disinfection cycles<\/li>\n
- Minimises peak load conflicts between DHW and space heating<\/li>\n<\/ul>\n
Key Configuration Parameters:<\/strong><\/p>\n\n- DHW setpoint temperature:<\/strong> 45\u00b0C\u201355\u00b0C for standard use; 60\u00b0C for thermal disinfection<\/li>\n
- DHW operating time:<\/strong> Scheduled windows aligned with demand patterns (e.g. 05:00\u201307:00 and 17:00\u201320:00)<\/li>\n
- DHW priority:<\/strong> Defines whether DHW or space heating takes precedence when both are demanded simultaneously<\/li>\n
- Thermal disinfection (Legionellenschutzschaltung):<\/strong> Weekly cycle heating DHW cylinder to minimum 60\u00b0C as required by DVGW W 551 (Germany)<\/strong> and \u00d6NORM B 5019 (Austria)<\/strong><\/li>\n
- Cylinder hysteresis:<\/strong> Temperature band within which the cylinder is recharged (typically 3\u20135 K below setpoint)<\/li>\n<\/ul>\n
Regulatory Requirement:<\/strong> According to EU Drinking Water Directive (2020\/2184)<\/strong> and national implementing regulations, DHW systems in buildings with central heat production must include legionella protection measures. Control configuration of thermal disinfection is a legal compliance requirement, not an optional setting.<\/p>\nBuffer Tank Configuration (Pufferspeicher-Regelung)<\/h3>\n
Definition:<\/strong> Buffer tank configuration defines how the heat pump charges, maintains, and discharges a hydraulic buffer tank (Pufferspeicher) that decouples heat production from heat distribution.<\/p>\nPurpose:<\/strong> It extends minimum heat pump run times, reduces compressor start frequency, and stores thermal energy for peak demand periods.<\/p>\nBenefits:<\/strong><\/p>\n\n- Protects the compressor by preventing starts shorter than minimum run time (typically 10\u201315 minutes)<\/li>\n
- Allows off-peak electricity tariff charging (night-rate storage)<\/li>\n
- Stabilises system hydraulics in multi-zone installations<\/li>\n<\/ul>\n
Configuration Parameters:<\/strong><\/p>\n<\/div>\n\n
\n\n\n| Parameter<\/th>\n | Function<\/th>\n | Typical Value<\/th>\n<\/tr>\n<\/thead>\n |
\n\n| Upper buffer sensor setpoint<\/td>\n | Triggers heat pump stop when reached<\/td>\n | Flow temp + 3\u20135 K<\/td>\n<\/tr>\n |
\n| Lower buffer sensor setpoint<\/td>\n | Triggers heat pump start when reached<\/td>\n | Flow temp \u2013 3\u20135 K<\/td>\n<\/tr>\n |
\n| Minimum run time<\/td>\n | Prevents compressor short cycling<\/td>\n | 10\u201315 min<\/td>\n<\/tr>\n |
\n| Minimum off time<\/td>\n | Prevents rapid restart after shutdown<\/td>\n | 3\u20135 min<\/td>\n<\/tr>\n |
\n| Buffer volume<\/td>\n | Must match minimum run time calculation<\/td>\n | \u2265 5 litres per kW heat output<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nModulation and Capacity Control (Leistungsregelung)<\/h3>\nDefinition:<\/strong> Capacity control configuration defines how the compressor varies its output relative to instantaneous heating demand. In inverter-driven heat pumps, this means configuring the variable-speed compressor’s operating range and modulation response.<\/p>\nPurpose:<\/strong> It matches heat pump output to the actual load, avoiding both energy waste at low demand and comfort shortfalls at peak demand.<\/p>\nBenefits:<\/strong><\/p>\n\n- Improves seasonal COP by running at lower frequencies during mild weather<\/li>\n
- Reduces noise output at partial load<\/li>\n
- Reduces thermal cycling stress on refrigerant circuit components<\/li>\n<\/ul>\n
Practical Application:<\/strong><\/p>\nFor iDM inverter heat pumps, the minimum and maximum compressor frequency must be set within the manufacturer’s approved operating window. Setting minimum frequency too low causes unstable refrigerant flow. Setting maximum frequency too high at low outdoor temperatures causes high discharge pressure faults. The iDM Navigator 2.0 automatically limits frequency based on outdoor temperature using a pre-programmed envelope map.<\/p>\n SG Ready Configuration (Smart Grid)<\/h3>\nDefinition:<\/strong> SG Ready (Smart Grid Ready) is a standardised four-state interface defined by the German Heat Pump Association (BWP)<\/strong> that allows a heat pump to receive operating state commands from an external energy management system, grid operator, or smart meter.<\/p>\nPurpose:<\/strong> It enables the heat pump to consume electricity when it is cheap, green, or abundant \u2014 and reduce consumption when the grid is stressed or tariffs are high.<\/p>\nThe Four SG Ready States:<\/strong><\/p>\n<\/div>\n\n \n\n\n| State<\/th>\n | Signal<\/th>\n | Heat Pump Behaviour<\/th>\n<\/tr>\n<\/thead>\n | \n\n| 1<\/td>\n | Locked<\/td>\n | Operation blocked (e.g. grid overload)<\/td>\n<\/tr>\n | \n| 2<\/td>\n | Normal<\/td>\n | Standard operation per configured schedule<\/td>\n<\/tr>\n | \n| 3<\/td>\n | Boosted<\/td>\n | Increased setpoints for storage charging<\/td>\n<\/tr>\n | \n| 4<\/td>\n | Maximum<\/td>\n | Run at maximum capacity for grid service<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nBenefits:<\/strong><\/p>\n\n- Reduces electricity cost by shifting consumption to off-peak periods<\/li>\n
- Enables direct use of surplus photovoltaic (PV) electricity<\/li>\n
- Supports grid balancing services and qualifies for grid-flexible tariff products in Austria (e.g. APG balancing energy market<\/strong>) and Germany (\u00a7 14a EnWG flexibility obligation<\/strong>)<\/li>\n<\/ul>\n
Regulatory Context:<\/strong> From 1 January 2024, \u00a7 14a EnWG (Germany)<\/strong> requires grid operators to offer reduced-tariff contracts for controllable consumption devices, including heat pumps. Correct SG Ready configuration is required to access these tariffs. In Austria, the ElWOG 2010<\/strong> and its 2023 amendment enable smart tariff structures applicable to heat pump systems.<\/p>\nZone Control Configuration (Mehrzonenregelung)<\/h3>\nDefinition:<\/strong> Zone control configuration defines independent heating circuits (Heizkreise) within a single heat pump installation, each with its own flow temperature, schedule, and control logic.<\/p>\nPurpose:<\/strong> It allows different parts of a building to receive different heat outputs at different times, matching the thermal characteristics and occupancy patterns of each zone.<\/p>\nBenefits:<\/strong><\/p>\n\n- Reduces energy consumption in unoccupied zones<\/li>\n
- Enables low-temperature underfloor heating and higher-temperature radiator circuits to coexist<\/li>\n
- Supports different user comfort preferences across zones<\/li>\n<\/ul>\n
Configuration Requirements:<\/strong><\/p>\n\n- Each zone requires a dedicated mixing valve (Mischventil) or separate secondary pump<\/li>\n
- Zone setpoint temperatures must be individually configured<\/li>\n
- Zone schedules must be coordinated with the main heat pump operating schedule<\/li>\n
- Minimum flow rate across all zones must remain within the heat pump’s hydraulic envelope at all times<\/li>\n<\/ul>\n
Anti-Freeze and Operating Limit Configuration<\/h3>\nDefinition:<\/strong> Anti-freeze configuration defines the minimum flow temperature and operational limits below which the heat pump activates or restricts operation to prevent freezing of the hydraulic system.<\/p>\nPurpose:<\/strong> It protects the heat pump, pipework, and heat emitters from frost damage during unoccupied periods or system standby.<\/p>\nBenefits:<\/strong><\/p>\n\n- Prevents costly freeze damage in systems with extended setback periods<\/li>\n
- Maintains minimum pipe temperatures in exposed locations (e.g. underfloor heating in unheated garages)<\/li>\n
- Complies with building insurance requirements in alpine regions (Austria, Switzerland, South Tyrol)<\/li>\n<\/ul>\n
Configuration Parameters:<\/strong><\/p>\n\n- Minimum flow temperature setpoint: typically 15\u00b0C\u201320\u00b0C in frost protection mode<\/li>\n
- Outdoor temperature threshold: activation below typically +3\u00b0C to +5\u00b0C<\/li>\n
- Pump run-on time after heat pump stop: 2\u20135 minutes<\/li>\n<\/ul>\n
Fault Monitoring and Error Logging Configuration<\/h3>\nDefinition:<\/strong> Fault configuration defines sensor error thresholds, alarm relay outputs, and remote notification triggers within the heat pump control system.<\/p>\nPurpose:<\/strong> It ensures that operating faults are detected early, logged for diagnostic purposes, and communicated to the installer or building manager before system failure occurs.<\/p>\nBenefits:<\/strong><\/p>\n\n- Reduces unplanned downtime through early fault detection<\/li>\n
- Provides documented operating history for warranty and insurance purposes<\/li>\n
- Enables remote service access by qualified installers (e.g. via iDM remote monitoring portal)<\/li>\n<\/ul>\n
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