Air-to-air heat pumps are most practical to operate in areas where the lowest winter temperature does not go below ______ *F?

Air-to-air heat pumps function by transferring heat from outside air to inside a building, making them efficient in moderate climates. They become less efficient as outdoor temperatures drop. The practical operating range typically restricts these units to environments where the minimum winter temperature does not fall below 10°F.

When temperatures dip below this point, the efficiency of the heat pump can significantly decline, often requiring supplementary heating systems to maintain comfortable indoor conditions. This can lead to higher operating costs and less energy efficiency.

By operating in areas where winter temperatures do not fall below 10°F, homeowners can maximize the heat pump's performance, ensuring it works effectively without the need for excessive backup heating.