Selecting the correct wattage is critical for efficiency. As a rule of thumb, you need approximately 1kW of power for every 10 square meters of space with a standard ceiling height. However, for industrial applications or poorly insulated buildings, you should factor in a 20-30% safety margin to ensure the system can maintain temperatures during extreme cold. Always verify if your facility's electrical grid can handle the peak load, especially for high-capacity units exceeding 24kW which typically require three-phase power (380V-415V).