Fan coil units, chilled beams, climate ceilings and air handling units are only as efficient as the hydronic control design behind them. When hydronic control is not optimised, terminal units struggle to deliver the comfort, efficiency and reliability they were designed for.
IMI’s hydronic HVAC system solutions and deep technical insight protect design intent through accurate flow limitation and stable part-load control, supported by transparent operational data that enables continuous optimisation as system conditions change. At the same time, pressurisation, air and dirt separation, and degassing solutions safeguard the wider system by maintaining correct pressure, removing air and contaminants, and protecting long-term performance.
Together, these technologies help terminal units operate as intended, delivering stable comfort and energy efficiency throughout the life of the building.
Maintaining that performance becomes most challenging where the system meets the room: clogging, tight ceiling voids and space constraints. These issues are most critical during partial load operation, where terminal units spend around 80% of the year and where control accuracy typically degrades. Our solutions maintain stable flow control across the full operating range, enabling consistent room temperature and comfort.
Clogging does not just block coil flow, it breaks coil performance
Dirt, air and oxygen ingress can disrupt flow, destabilise temperatures and place unnecessary strain on critical components. Debris, magnetite and trapped air can accumulate in control valves, coils and pumps, restricting flow and reducing heat transfer efficiency.
The consequences go far beyond simple blockages. Clogging can cause unstable control behaviour, increased energy consumption and higher maintenance requirements. Over time, it can also accelerate component wear and increase the risk of unexpected downtime.
Effective system protection begins with proactive management of air and contaminants within the hydronic circuit. IMI Pneumatex degassers, air and dirt separators capture contaminants before they impact performance. Our hydronic expertise helps diagnose water quality issues and ensure adequate protection, while dirt-resistant pressure independent balancing and control valves (PIBCVs) maintain consistent performance even under harsh conditions. The result is reliable, efficient and predictable operation.
Tight ceiling voids and space constraints
Space constraints in tight ceiling voids do not just hide valves, they hide problems.
Limited space should never mean compromised installation or maintenance. IMI addresses challenging ceiling voids with TA-Sixline and TA-Nano, both featuring a compact valve body and slim actuator design to fit where terminal units live. TA-Sixline optimises changeover in 4-pipe heating and cooling systems such as climate ceilings, while TA-Nano delivers precise control for fan coil units and chilled beams.
360° actuator rotation with TA-Sixline provides installation flexibility in tight spaces, while side-visible valve setting and accessible measuring points on TA-Nano support rapid diagnostics and system verification.
Unstable flow breaks control at the terminal unit
Incorrect valve sizing and pressure instability cause temperature fluctuations, noise, hunting and excessive pumping energy. IMI’s guidance and solutions ensure valves are precisely sized and correctly positioned from the start. With its EQM characteristic, the TA-Modulator PIBCV and TA-Slider actuator provide exact flow control even at low loads, while integrated flow and differential pressure verification support fast commissioning, reliable operation and proof that design performance is maintained across the system lifecycle. Flow setting and verification via the HyTune app with TA-Slider ensures design flow matches real flow at the terminal unit.
Taking back control where the system meets the room
With solutions tailored to every challenge at terminal unit level, IMI’s solutions and technical insight ensure stable operation and precise control, driving efficiency in every terminal unit.
For more information visit: IMI Hydronic solutions