Pittsburgh's 75% average summer humidity makes SEER ratings only part of the efficiency equation. Air conditioners remove moisture through condensation on evaporator coils, but single-stage systems cycle off before properly dehumidifying homes. Higher SEER equipment typically includes variable-speed or two-stage compressors that run longer at lower capacity, pulling more moisture from indoor air. This matters when dew points climb above 70 degrees during July and August near the rivers. The Ohio and Monongahela create localized humidity that standard SEER calculations do not fully capture. Homes in low-lying neighborhoods need equipment that excels at latent cooling, not just sensible temperature reduction.
Pittsburgh's seasonal temperature swings from below zero to above 90 degrees demand equipment capable of efficient operation across wide ambient conditions. Federal SEER testing uses specific temperature and humidity conditions that do not represent our full cooling season. Heat pumps with high SEER ratings often include enhanced vapor injection or two-stage compressors that maintain capacity during temperature extremes. Local HVAC expertise means understanding which efficiency features perform reliably through Pittsburgh's variable spring and fall weather when overnight lows drop 30 degrees below afternoon highs. Equipment selection requires analyzing performance curves across our actual operating conditions rather than relying solely on laboratory SEER ratings.
