How to Choose an Air Conditioner by Room Area and Heat Gains (Apartment/Office/Store)

Choosing the right air conditioner is not only about room size. To get stable comfort and avoid excessive energy bills, you need to match the cooling capacity to both the area and the real heat gains (теплопритоки) in the space. A quick starting point for typical rooms with standard ceilings is about 100 W of cooling per 1 m² (≈0.1 kW/m²). For example, 20 m² needs roughly 2.0 kW, and 35 m² needs about 3.5 kW. This rule works best for an apartment bedroom or living room with moderate sun and few people. Next, adjust for heat gains. Add capacity if the room is sunny (south/west windows), has large glazing, poor insulation, or is on the top floor. People also generate heat: plan extra cooling for meetings or busy rooms. Equipment matters too: computers, server racks, lighting, cooking devices, and shop refrigeration can significantly increase the load. In offices, multiple PCs and printers often push the required capacity above the “by area” estimate. In stores, frequent door opening and customer traffic add warm air infiltration, so a stronger unit—or multiple units—may be needed. A practical approach: calculate the base load by area, then add a safety margin of 15–30% depending on sun exposure and equipment. Avoid oversizing: a unit that is too powerful will short-cycle, remove less humidity, and feel uncomfortable. Also consider installation constraints (indoor unit placement, outdoor unit location, drainage) and select an inverter model for better efficiency and quieter operation. For complex spaces, request an HVAC professional load calculation to choose the optimal split system or multi-split solution.