When it comes to assessing the energy efficiency of an air conditioning system, the Energy Efficiency Ratio (EER) is one of the most reliable metrics. This ratio is calculated by dividing the cooling power (in British Thermal Units or BTU) by the electrical input (in watts) of an air conditioner or heat pump. Another way to measure the performance of an HVAC system is to observe the change in temperature at a given point. To do this, you can take temperature readings in a specific area of the building over a period of time.
The rate at which the temperature drops and how much it drops will indicate how well the system is functioning. These methods are often used to evaluate different types of systems, allowing HVAC professionals and customers to understand how a particular unit is expected to perform.