Pressure Drop Is Part of the Cost
Every exchanger adds static pressure. The fan must deliver the design airflow at the new total pressure, and fan power rises with both flow and pressure. Ignore this and you can lose a chunk of the recovered energy to the fan.
Typical Ranges
- Plate core: 50-150 Pa per side at design velocity
- Rotary wheel: 100-250 Pa including the wheel and seals
- Heat pipe: 40-120 Pa, usually the lowest
Sizing the Fan
Take the clean-filter pressure drop from the datasheet, add duct and filter losses, then select a fan with adequate static capability and check its efficiency at the operating point.
Trade-off With Effectiveness
Lower face velocity raises effectiveness but enlarges the core and can change pressure drop non-linearly. The optimum is where the value of recovered energy minus extra fan energy is maximised.
Verification
During commissioning, measure actual pressure drop and compare with the design; a large gap signals fouling or a wrong selection.
What This Product Does
This unit is built as a compact air-to-air heat exchanger that transfers thermal energy between two separate air streams without allowing them to mix. Warm exhaust air passes over one side of the core while cooler supply air passes over the other, and the temperature difference drives heat from the warm stream to the cool one. The result is pre-conditioned make-up air that needs far less external heating or cooling, which lowers the load on the building or process system.
Construction and Materials
The core is formed from corrugated aluminium or stainless-steel plates bonded into a counter-flow pack, with sealed channels that keep the two air paths isolated. Frames are typically galvanised or powder-coated steel, and service doors give access for inspection and cleaning. Gasket materials are selected for the operating temperature and any mild chemical exposure, so the unit stays reliable in demanding ventilation duties.
Where It Fits
In the Heat Exchanger Pressure Drop and Fan Sizing configuration the exchanger is suited to HVAC make-up air units, paint and coating ovens, food and pharmaceutical drying, and general process ventilation where energy cost is a concern. It can be mounted horizontally or vertically to match the available plant layout, and it connects with standard flanged ductwork for straightforward integration with existing fans.
Frequently Asked Questions
Does it need power to operate? The passive core needs no electricity; only the associated fans and controls consume power. How often should it be cleaned? Inspect at least once per season and clean the exhaust side when temperature recovery begins to drop.