Variable-speed compressor technology can increase efficiency of air conditioners and heat pumps by reducing the cycle's temperature lift. However, the increase in evaporating temperature is constrained by indoor comfort requirements. Latent loads depend on outdoor climate, due to air infiltration. Varying the indoor blower speed can provide the necessary humidity control by adjusting the evaporator surface temperature to meet latent loads at any compressor speed. Together these variable-speed technologies can make it possible to maximize efficiency subject to indoor comfort constraints over a wide range of outdoor climatic conditions. This paper adds sensible and latent load equations to a detailed residential-scale vapor compression system simulation model to quantify trade-offs between indoor comfort and system energy efficiency.

Units: Dual