Four basic processes
On the psychrometric chart, ventilation air moves along predictable lines:
- Heating: horizontal line to the right (dry-bulb up, moisture constant).
- Sensible cooling: horizontal line to the left (dry-bulb down, moisture constant).
- Humidification: line upward (more moisture).
- Dehumidification: line downward (condensation, latent heat released).
Sensible recovery = a move along the constant-humidity line
A cœur à plaques pre-heats or pre-cools the supply along a constant-humidity path: dry-bulb temperature changes, moisture does not. It is the simplest, cleanest recovery for separated airstreams.
Total-energy recovery = a move toward the exhaust state
A rotary enthalpy wheel or membrane pulls the supply state toward the exhaust state in both temperature and humidity. In winter, cold dry outdoor air approaches the warmer, more humid exhaust – picking up sensible and latent energy and cutting both heating and humidification load.
Where frost enters the picture
When exhaust falls below its dew point and frost point, moisture deposits as ice on the core. This is why cold-climate designs need defrost strategy, not just a bigger wheel.
Frequently asked questions
Does recovery change indoor RH? Sensible-only recovery does not; total-energy recovery can steady indoor humidity because it transfers moisture too.
Which process saves more energy in summer? In humid summers, the dehumidification (downward) leg of total recovery relieves the cooling coil most.
Need help specifying the right air-to-air heat recovery for your project? Contact the QIYU engineering team – WhatsApp +86 157 5335 5505, or email kuns913@gmail.com.
Questions fréquemment posées
How does a heat recovery process appear on the chart?
Sensible recovery moves a state horizontally (temperature change, same moisture); enthalpy recovery moves it along a line blending both temperature and moisture toward the supply state.
Why do cooling and recovery processes often combine on the chart?
Precooling the exhaust with incoming air lowers the wet-bulb the cooling coil must handle, shrinking coil load and sometimes letting a smaller coil meet the setpoint.
Questions fréquemment posées
How does a heat recovery process appear on the chart?
Sensible recovery moves a state horizontally (temperature change, same moisture); enthalpy recovery moves it along a line blending both temperature and moisture toward the supply state.
Why do cooling and recovery processes often combine on the chart?
Precooling the exhaust with incoming air lowers the wet-bulb the cooling coil must handle, shrinking coil load and sometimes letting a smaller coil meet the setpoint.
Spécifiez le bon échangeur
Nos ingénieurs dimensionnent le noyau selon votre débit, température et budget de perte de charge, et choisissent la récupération par plaque, rotative ou caloduc selon l'application. Lisez le guide de l'échangeur , ou contactez-nous pour une spécification.
Produits connexes
Récupération par plaque, rotative ou caloduc pour le CVC et la ventilation.
Noyaux stationnaires à grande surface pour l'air et le liquide.
Récupération d'énergie à haute efficacité pour grands débits.
Courants passifs et totalement séparés pour applications propres.