Counter-flow heat exchangers
95%
Efficiency
ZERN ENGINEERING counter-flow heat exchangers deliver maximum thermal efficiency with complete separation of supply and exhaust air. Built with polystyrene (sensible) or vapor-permeable polymer membranes (enthalpy), they provide reliable energy recovery for residential, commercial, and industrial AHUs/ERVs.
Product categories
Types and variations
Sensible counter-flow heat exchangers
Series:
HU / HS / HC / HD-EX6
Thermoformed polystyrene cores for high heat recovery with low pressure drop. Monolithic, fully sealed structure prevents cross-contamination and is suitable for low- to medium-pressure systems.
Enthalpy counter-flow heat exchangers
Series:
ECD / EC-EX6
Polymer plates bonded with a microporous, vapor-permeable membrane recover both heat and moisture - ideal for cold or dry climates and RH control.
Combi counter-flow heat exchangers
Series:
Combi HU/HC-EX6
Twin-core modules joined by common plenums to handle higher airflows with a lower pressure drop while keeping all counter-flow benefits.
Key operational parameters
Performance сharacteristics
Thermal efficiency
Up to 95% under optimal conditions.
Humidity efficiency
Up to ~80% (depending on modes and RH).
Airflow range
Standard models 50–6,000 m³/h; larger customized solutions available on request.
Operating temperature
−25 °C to +50 °C.
Pressure drop
Typically, 40-150 Pa (depends on airflow and core size).
Service life and maintenance
Сores are non-corrosive, washable and remain effective for many years.
Technical features
Design and structure
Principle of operation
In counter-flow heat exchangers, two air streams flow in opposite directions through thin channels formed by a layered polystyrene or polymer membrane structure. This counter-flow configuration ensures a consistently high temperature gradient across the entire core length, enabling highly efficient heat transfer.
- Sensible models: transfer heat only.
- Enthalpy models: transfer both sensible and latent heat and moisture, while blocking dust, dirt, odours, CO₂ and other gases.
- Optional: bypass and damper enables free-cooling and mode switching.
Core material
Thermoformed polystyrene plates or polymer-based enthalpy plates arranged in a tightly packed structure. The design provides:
- High surface area for effective thermal transfer.
- Low air resistance thanks to an optimized channel geometry.
- No risk of corrosion or germ growth (non-metallic material).
Casing materials
- Polystyrene (HIPS) — lightweight, insulated; ideal for compact residential units.
- Aluzinc steel — economical and corrosion-resistant for long-lasting performance.
- Aluminum — lightweight, corrosion-resistant; good for humid sites.
- Epoxy-coated — for chemically active or coastal areas.
- Stainless steel (AISI 304/316) — for aggressive/hygienic sites.
Main areas of use
Applications
- Residential buildings — apartments, apartment complexes, private homes.
- Commercial facilities — offices, shopping and business centers, schools, cultural institutions.
- Industrial systems — production workshops, warehouses, logistics complexes.
- Hotel and wellness sector — hotels, sports and fitness centers, swimming pools (enthalpy models provide additional humidity control).
- Public spaces — airports, exhibition halls, stadiums, transport hubs.
