By Design Tech Solutions — Specialists in Heat Interface Unit Optimisation
Introduction: The HIU Is Where Network Performance Is Won or Lost
In any district heating system, the heat interface unit (HIU) is the final gateway between the network and the end user. If HIUs are poorly specified, installed, or controlled, they can cause low efficiency, high return temperatures, and user complaints — even if the network itself is well-designed.
At DTS, we treat HIUs not as a commodity, but as a critical control point — and we optimise every aspect of how they function, from zoning logic to commissioning data.
Why HIU Performance Matters
Return Temperatures
High return temps from poorly performing HIUs drastically reduce efficiency and make heat pumps or low-temp design ineffective.
Billing & Metering Accuracy
Subpar HIUs can produce inaccurate readings or fail to capture real-time usage data — impacting fair billing.
User Comfort
Temperature delays, noise, or fluctuating DHW output lead to tenant dissatisfaction.
System Balancing
Unbalanced flows at HIUs create uneven pressure, affecting performance across the wider network.
Smart Control Features We Enable
Return temperature limitation
Flow control based on room/zone demand
Data feedback into SCADA/BMS dashboards
Timed pre-heat and DHW boost features
Alarms and alerts for flow anomalies or temperature spikes
Design Considerations
Positioning: allow for access, sensor placement, and metering
Flushing valves and bypasses: included for commissioning
Control logic: defined in coordination with plant room settings
User training: ensure users understand how their systems work
DTS Approach to HIU Optimisation
Model-Specific Specification
We select HIUs based on building type, temp regime, user profile, and compliance needs.
Pre-Commissioning Guidance
We provide flushing, valve setting, and flow rate recommendations to reduce commissioning delays.
Smart Controls & Sensors
We support integration of room sensors, weather compensation, and real-time feedback loops to maintain comfort and reduce return temps.
Ongoing Monitoring Design
We design with data points that support fault diagnostics, performance dashboards, and proactive maintenance.
FAQ
Let’s Get the Most From Every HIU
Small units, big impact. DTS helps you deliver HIU performance that maximises efficiency and minimises complaints — with smarter control, from day one.
RELATED READS
Explore our detailed guides on designing effective, future-ready district heating systems. Each article is written to help clients, developers, and stakeholders understand what great network design looks like in practice.
