It is not necessarily common sense that a one-level house needs a larger air conditioning (AC) size than a two-level house with the same square footage. The size of the AC required for a house depends on various factors, and the number of levels is just one of them.
The primary factors that influence the size of the AC unit needed for a home include:
Square footage: The total area of the house is a significant factor in determining the capacity of the AC required. Larger homes generally need larger AC units.
Ceiling height: The height of the ceilings can affect the cooling needs of a home. Higher ceilings may require more cooling capacity.
Insulation: The level of insulation in the house affects how well it retains cool air. A well-insulated house may require a smaller AC unit.
Climate: The climate of the region where the house is located plays a crucial role. Hotter and more humid climates typically require larger AC units to maintain comfortable temperatures.
Windows and orientation: The number of windows, their size, and their orientation to the sun can impact the heat gain in the house, affecting the AC requirements.
Heat-producing appliances: The presence of heat-generating appliances (like ovens, dryers, etc.) and the number of occupants in the house can influence cooling needs.
While a two-story house may have better natural airflow and might distribute cool air more effectively, it doesn't necessarily mean it needs a smaller AC unit. On the contrary, a two-story house may have additional cooling needs due to heat rising to the upper levels.
To determine the appropriate AC size, it is essential to perform a load calculation, which takes into account all these factors and provides an estimate of the cooling capacity required for the specific house. HVAC professionals typically carry out such calculations to ensure the AC system is appropriately sized for efficient and effective cooling.