Methods for Calculating the Air Conditioning Area Ratio in Various Venues
I. Core Calculation Principles and General Formulas
The core basis for air conditioner selection is the total cooling capacity required by the room . All places use the same basic calculation formula, which is then fine-tuned based on the scenario, environment, and structural parameters to adapt to all scenarios, including residential and commercial use.
Basic formula : Total cooling capacity (W) = Room area (㎡) × Cooling capacity per unit area (W/㎡) × Correction factor
Unit conversion (general industry practice)
- 1 horsepower air conditioner ≈ 2500W cooling capacity (standard household use)
- 1 kilowatt (kW) = 1000 watts (W), 1 refrigeration ton ≈ 3500W (large commercial models)
- The standard floor height is 2.6–2.8m; any height exceeding this requires additional expansion.
II. Standards for Cooling Capacity per Unit Area in Various Venues (Precise Proportioning Table)
The following values are the baseline parameters for normal temperature, standard floor height, normal lighting, and normal enclosed environment, which are suitable for most scenarios and are the core basis for selection.
1. Residential and residential spaces
- Bedroom (Master Bedroom/Secondary Bedroom) : 150–200W/㎡
For standard apartment layouts, no western exposure, not top floor, and smaller windows, choose 150-180W/㎡; for western exposure, top floor, and large floor-to-ceiling windows, choose 180-200W/㎡.
- Living room/dining room (home use) : 180–220W/㎡
For spaces with high human activity, large heat generation from electrical appliances, and open spaces, use the upper limit; for small, enclosed spaces, use the lower limit. - Study/Children's Room : 140–180W/㎡
With fewer staff and fewer heating devices, the standard environment is set at the lower limit, while the western-facing apartment type is appropriately adjusted upwards.
2. Office and business premises
- Standard office (closed) : 200–250W/㎡
For single or double offices, use the lower limit; for multi-person, densely packed offices with multiple computer devices, use the upper limit.
- Open-plan office space : 250–300W/㎡
High population density, concentrated equipment, and rapid air circulation necessitate increased cooling load.
- Meeting room : 300–350W/㎡
Short-term high-density population density and high heat generation necessitate high-load allocation.
- Reception Area : 280–320 W/㎡
High personnel flow, frequent opening and closing of doorways, and frequent exchange of hot and cold temperatures
3. Commercial premises
- Shopping malls/retail shops : 300–380W/㎡
With high foot traffic, dense lighting, and frequently open doors and windows, the entrance area on the first floor requires an additional 15%–25% load. - Supermarket/Fresh Food Section : 350–400 W/m²
The equipment generates a lot of heat, has a high density of people, and requires large ventilation; therefore, the fresh food area needs to have a separate, larger proportion of equipment. - Milk tea shop/snack shop : 400–500W/㎡
The kitchen equipment generates extremely high heat and produces a lot of oil fumes and heat, making it an ultra-high-load scenario. - Beauty salons/wellness centers : 220–280W/㎡
; long customer dwell time, enclosed space, equipment generates some heat. - Hotel guest rooms : 180–220W/㎡.
Enclosed spaces with fixed occupants; lower limit for standard room types, upper limit for large rooms with floor-to-ceiling windows.
4. Special public places
- Gym : 350–450W/㎡
People moving around generate a lot of heat, the space is open, and the ventilation requirement is high. - Cinema/Lecture Hall : 320–380W/㎡
Crowded, enclosed, poorly ventilated, and prolonged gatherings - KTV/Chess and Card Room : 300–350W/㎡
Enclosed spaces, concentrated populations, and high heat generation from electrical appliances and lights - Factory/Workshop (Standard) : 250–350W/㎡
Adjustments should be made flexibly based on equipment heat dissipation and personnel density; workshops with high-temperature equipment require an increase to 400W/㎡ or higher.
III. Key Correction Factors (Determining the Accuracy of Model Selection)
The basic calculation results need to be corrected in combination with environmental and structural conditions. Multiple conditions can be superimposed and multiplied to avoid the air conditioner being underpowered or wasting energy.
- Floor adjustment : Top floor +1.1~1.2 times, middle standard floors 1.0 times, bottom floor (no dampness) 1.0 times.
- Orientation correction : West-facing rooms +1.1~1.15 times, all-sunny rooms +1.05 times, shady rooms +1.0 times.
- Floor height adjustment : Base height 2.8m, increase by 1.05 times for every 0.2m increase, and for spaces with a height of 3.5m or more, increase by 1.2 to 1.3 times.
- Door and window adjustments : Large floor-to-ceiling windows/glass curtain walls +1.15~1.25 times, ordinary doors and windows 1.0 times.
- Airtightness correction : Frequent door openings and open, transparent spaces +1.1~1.2 times.
IV. Quick Conversion of Horsepower and Area Matching Table (Foolproof Selection Guide)
Based on standard environments, no calculations are required; matching is done directly by area, making it suitable for quick selection and reference.
- 1 horsepower (2500W) : Suitable for 10–15㎡ (small bedroom, small study)
- 1.5 HP (3500W) : Suitable for 15–23㎡ (standard bedroom, small living room)
- 2HP (5000W) : Suitable for 23–32㎡ (large bedroom, small office, dining room)
- 3HP (7200W) : Suitable for 32–48㎡ (large living room, medium-sized office, small shop)
- 5HP (12000W) : Suitable for 48–80㎡ (large office areas, medium-sized shops, conference rooms)
- Commercial machines of 10 horsepower and above : Large shopping malls, factories, and halls of 80 square meters or more (calculated according to a precise formula).
V. Complete Calculation Example
Example 1: A west-facing bedroom on the top floor of a residential building, with an area of 18 square meters.
Basic cooling capacity = 18㎡ × 190W/㎡ = 3420W; 1.1 times for top-floor stacked apartments, 1.1 times for west-facing apartments.
Total cooling capacity = 3420 × 1.1 × 1.1 ≈ 4138W → Select a 2-horsepower air conditioner
Example 2: Open-plan office area, 60㎡, densely populated with multiple people working together.
Basic cooling capacity = 60㎡ × 280W/㎡ = 16800W, standard floor height environment
Total cooling capacity ≈ 16800W → Select 2 x 5HP commercial air conditioners or 1 x 10HP commercial unit
VI. Key Points for Avoiding Pitfalls in Product Selection
- All calculation results should be rounded up for selection , and underestimation is strictly prohibited. A 10%–20% load margin should be reserved to cope with extreme high-temperature weather.
- In commercial settings with high foot traffic and numerous heat-generating devices, the calculation should be based on the upper limit of the range, without using the lower limit.
- For venues with extremely high ceilings, glass curtain walls, and frequent street-facing entrances, all correction factors must be applied.
- Multi-split systems and central air conditioning systems need to be calculated separately for each room, not by averaging the total area.
