The statement that an air conditioning unit is only made to cool 15 degrees Fahrenheit (8.3 degrees Celsius) cooler than the outside temperature is not a universal rule. The cooling capacity of an air conditioner depends on various factors, including its size, efficiency, the outdoor temperature, humidity levels, and the insulation and size of the space it is trying to cool.
Air conditioning units are designed to maintain a certain temperature differential between the inside and outside of a building. This temperature difference is typically referred to as the "temperature drop" or "delta T." In ideal conditions, a well-sized and efficient air conditioner can achieve a temperature drop of around 15 to 20 degrees Fahrenheit (8.3 to 11.1 degrees Celsius). However, this can vary based on several factors.
In extremely hot and humid conditions, the cooling capacity of an air conditioner may decrease, leading to a lower temperature drop. If the unit is undersized for the space it needs to cool or if there are issues with the ductwork or insulation, the temperature drop may also be less than expected.
Modern air conditioning units with higher SEER (Seasonal Energy Efficiency Ratio) ratings are generally more efficient and can achieve better cooling performance, even in challenging conditions. It's important to choose an appropriately sized air conditioner for the space you want to cool and to have it properly maintained to ensure optimal performance.
For accurate information about the cooling capacity of a specific air conditioning unit, it's best to refer to the manufacturer's specifications or consult with an HVAC professional. They can assess your cooling needs and recommend the most suitable system for your requirements and local climate conditions.