Rowhouses are iconic in Washington, D.C., but their narrow, multi-level layouts create challenges for cooling. Selecting the right size air conditioner is critical for comfort and efficiency. An undersized system won’t keep up with high summer heat, while an oversized unit may short-cycle, causing uneven cooling and wasted energy. Load calculations performed by HVAC professionals consider square footage, insulation, window placement, and occupancy. Ductless mini-splits are often a smart solution for rowhouses, offering zoned comfort without extensive ductwork. Central AC can also work well when ducts are properly sealed and balanced. Choosing the right system size prevents high utility bills and constant repairs. For D.C. homeowners, professional sizing ensures reliable cooling, steady comfort on every level, and longer system lifespan.