The answer to 'what size air conditioner do I need for my house' is that the correct size air conditioner for your home depends on several factors, including the square footage of your home, the number of windows and doors, the climate, and the insulation levels. As a general guideline, you'll want an air conditioner that can provide between 20-30 BTUs (British Thermal Units) of cooling capacity per square foot of living space.
For example, a 1,500 square foot home would typically require an air conditioner with 30,000 to 45,000 BTUs of cooling capacity. It's important to have an HVAC professional perform a detailed load calculation to determine the right size unit for your specific home and needs. Choosing the wrong size can lead to inefficient cooling, high energy bills, and potential system issues.