Modern buildings bring in large volumes of fresh air, and exhausting that same air to outdoors wastes the energy spent conditioning it. A heat-recovery core inside the air-handling unit (AHU) transfers energy between supply and exhaust streams - cutting heating and cooling loads while meeting ventilation codes.
Core types
- Plate (fixed) cores - cross-flow or counter-flow; sensible recovery, simple and leak-free. The most common AHU choice.
- Rotary (wheels) - higher recovery and can transfer moisture (enthalpy); needs a purge sector to limit carry-over.
- Enthalpy (total) cores - plate or polymer membranes that recover both heat and humidity.
- Sensible vs total - sensible (显热) recovers temperature only; total (全热) recovers temperature and moisture.
Applications
- Commercial and public-building AHUs - offices, schools, hospitals.
- Retrofit of existing ventilation - add a recovery core to an AHU during a plant upgrade.
- Residential fresh-air systems - compact ERV units.
- Clean and semi-clean rooms - where air change is high.
Selection tips
- Match core size to design airflow and target recovery efficiency (counter-flow beats cross-flow).
- In humid climates, a total (enthalpy) core controls indoor humidity better than sensible-only.
- Size frost protection for cold-climate supply air (preheat or bypass).
For plate and rotary recovery cores for AHU and ERV duty, see rotary heat-recovery wheels and the Zibo Qiyu range, or request sizing.
Key takeaway
Fresh air is mandatory; wasting its conditioning is not. A recovery core is the cheapest energy a building can buy.
Fresh-air and HVAC systems rely on heat-recovery cores to cut the energy cost of conditioning outdoor air. In a typical air handling unit, the core sits between supply and exhaust paths and transfers heat through thin plates, so the incoming air is pre-conditioned before reaching the coil. This single component often delivers the largest efficiency gain in a ventilation design and reduces the load on both heating and cooling plant.
Plate cores are the common choice for clean indoor air because they isolate the streams and are simple to service. Enthalpy plates can also move some moisture, which helps in humid climates, while sensible plates move heat only and are preferred where air purity is critical, such as laboratories, hospitals, and food facilities.
When specifying a core for an AHU or ERV, confirm the plate material against the air quality and any corrosion risk. Aluminum serves most indoor applications; 316L stainless or coated plates suit aggressive or coastal exhaust. Face velocity, plate count, and channel height set both effectiveness and pressure drop, so the core must be matched to the fan budget rather than chosen by peak catalog figures.
Cleanability and filter placement protect long-term performance, because a fouled core loses effectiveness and raises energy use. For projects targeting energy labels, ask the supplier for test-based effectiveness at part-load, since units rarely run at full design flow. A well-specified core lowers utility cost and can shrink the required heating and cooling plant, improving the building's overall efficiency profile.