Latent Heat Ratio (LHR) measures the proportion of total cooling capacity used for moisture removal, calculated as the inverse relationship to Sensible Heat Ratio. This metric quantifies dehumidification performance and is essential for evaluating system suitability in humid climates. LHR values between 0.15 and 0.30 are typical for standard residential cooling systems.
Climate and Application Considerations
High latent heat loads occur in coastal and subtropical regions where outdoor air contains significant moisture. A system with LHR 0.25 dedicates 25% of cooling capacity to dehumidification. Humid climates may benefit from systems with enhanced latent capacity or standalone dehumidifiers, as higher LHR requirements drain cooling efficiency from sensible temperature reduction.
System Performance Evaluation
Contractors assess LHR alongside SHR to verify systems can maintain target humidity levels between 30% and 50%. Undersized sensible capacity or oversized equipment often produces inadequate latent heat removal, resulting in clammy conditions despite cool temperatures. Proper equipment selection based on local climate conditions and building characteristics ensures balanced sensible and latent cooling performance.