Potência elétrica AC
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The AC power calculator helps determine the electrical power in watts (W) of climate control equipment, such as air conditioners, using BTU (thermal capacity unit) and EER (energy efficiency rating). The formula used is P = BTU ÷ (3.412 × EER), where BTU measures cooling capacity and EER indicates the equipment's efficiency. This calculation is crucial for correctly sizing the electrical load in systems.
To use the calculator, input the BTU and EER values of the equipment. The factor 3.412 converts BTU to watts, aligning the unit with the International System. This allows assessing whether the electrical installation can support the appliance's load, preventing overloads or improper sizing. Ideal for climate control projects in homes, businesses, or industries.
Important: EER varies depending on the equipment's technology. Higher values indicate greater efficiency. The calculator does not account for factors like thermal losses in the environment or voltage fluctuations, which can affect real performance. Always consult a professional for complex installations or in locations with specific energy requirements.
Frequently asked questions
What is BTU and why is it used in air conditioners?
BTU (British Thermal Unit) measures the amount of heat an appliance can remove from a space in one hour. It is used to indicate the cooling capacity of devices like air conditioners.
How does EER impact the electrical power calculation?
EER (Energy Efficiency Ratio) shows the appliance's energy efficiency. A higher EER means the device uses less energy to provide the same cooling capacity, reducing the required electrical power.
Can I use the calculator for equipment other than air conditioners?
Yes, as long as BTU and EER values are provided. Equipment like heat pumps or fans can also be assessed using this formula.
Why is the factor 3.412 used in the formula?
The number 3.412 converts BTU/h (a thermal power unit) to watts, aligning the measurement with International System (SI) units.