The HRM-V Split Passive Heat Pipes Series is designed for projects where supply and exhaust air streams cannot be placed close together. Ideal for layouts requiring complete isolation to prevent cross-contamination, it offers higher effectiveness and better efficiency than water run-around systems—without moving parts.
Coilmaster’s HRM-V Split Passive Heat Pipes system uses multiple charged circuits, with two rows of heat exchangers, a vapor header at the top, and a liquid header at the bottom. A permanent elevational difference between supply and exhaust air streams enables optimized recovery for the season that yields the most BTUs, while still allowing partial recovery in the off-season.
Liquid-side control valves on each circuit allow recovery to be turned off during economizer conditions or closed to prevent frost in extreme cold.
For balanced recovery in both heating and cooling, HRM-V units can also be equipped with a Dynamic Seasonal Offset (DSO™) system, delivering about 45% effectiveness on a six-row system at 500 FPM. This system outperforms older side-by-side configurations by 20–35%, with higher sensible effectiveness and improved seasonal efficiency.
With Dynamic Seasonal Offset (DSO™)
Elevation difference between the supply and exhaust air streams drives thermo-syphon circulation within the HRM-V Split Passive Heat Pipes system. As warm exhaust air passes across the heat exchanger coil, the internal working fluid absorbs heat, evaporates, and rises through the vapor header. The vapor then condenses on the supply side, releasing thermal energy before returning through the liquid header.
This continuous heat exchange cycle operates without pumps or mechanical input. The permanent elevation offset improves fluid flow and heat transfer, allowing the system to maximize heat recovery during peak conditions while maintaining strong thermal performance and overall energy efficiency.
Split passive heat pipe systems are best suited for applications where supply and exhaust air streams cannot be located adjacent to each other. This often occurs in facilities with long duct runs, architectural constraints, or layouts that require separation between incoming air and outgoing air.
Applications that require complete airstream isolation, such as healthcare, laboratory, and industrial ventilation systems, benefit from this design. Maintaining separation helps protect indoor air quality and prevents cross-contamination between air streams.
Compared to traditional side-by-side heat exchangers or water run-around systems, this approach can deliver higher heat recovery in many layouts while eliminating pumps, piping, and added maintenance. This makes it a practical solution for ventilation systems and air handling unit designs where efficiency and simplicity are priorities.
Achieving optimal performance requires proper configuration of the heat exchanger circuits, airflow, and moisture management components. Multiple circuit options, including 2, 4, and 6 row heat exchangers, allow the system to be tailored to specific heat recovery requirements.
Moisture eliminators or extended drain pans may be required depending on operating conditions and airflow characteristics. Liquid-side control valves on each circuit provide flexibility to adjust or shut off heat recovery during economizer operation or extreme temperatures. Air flow, elevation difference, and coil configuration all influence heat transfer effectiveness and pressure drop. Careful system design ensures consistent performance while maintaining efficient ventilation and minimizing energy loss.
Long-term reliability is supported through a passive design that eliminates moving parts and reduces mechanical complexity. This minimizes the maintenance typically associated with active heat recovery systems. Routine upkeep includes periodic cleaning of the heat exchanger surfaces to remove dirt and debris and maintain proper airflow. Drainage components should also be inspected to ensure effective moisture management and prevent buildup.
For applications in corrosive or high-exposure environments, protective coatings can be applied to extend the life of the heat exchanger. These measures help maintain consistent heat recovery and reliable system operation over time.