❄️ Why Cooling Load Calculations Matter
Cooling load is the amount of heat energy that must be removed from a space to maintain a comfortable indoor temperature. An accurate cooling load calculation is the foundation of proper air conditioning sizing. An undersized AC unit cannot keep up on hot days; an oversized unit short-cycles, wastes energy, and fails to dehumidify properly.
This cooling load calculator estimates the sensible and latent heat gains for any room based on dimensions, insulation, windows, occupancy, climate, and internal loads. It outputs the total cooling load in BTU/h, kW, and tons of refrigeration, helping you select the right air conditioner for the space.
🔧 Cooling Load & AC Sizing Calculator
Enter room details below. The calculator estimates sensible heat gain, latent heat gain, total cooling load, and recommended AC tonnage using simplified ASHRAE methods.
m
m
m
°C
°C
m²
Total area of all windows in the room
W
W
L/s
Outdoor air introduced to the space (0 if none)
📊 Results
Sensible Heat Gain
—
BTU/h / kW
Envelope + solar + internal dry heat
Latent Heat Gain
—
BTU/h / kW
Moisture load from occupants & ventilation
Total Cooling Load
—
BTU/h / kW
Sensible + Latent — the required cooling capacity
Recommended AC Tonnage
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tons / kW
1 ton = 12,000 BTU/h = 3.517 kW
Cooling Load per Floor Area
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BTU/h/ft² / W/m²
Benchmark: 20–40 BTU/h/ft² (60–125 W/m²) typical
Note: Simplified ASHRAE method. Envelope loads use U-value × Area × ΔT. Solar gain uses SHGC × Window Area × Solar Irradiance (assumed 600 W/m² peak). Occupant sensible=75W/person, latent=55W/person. Ventilation load based on outdoor air enthalpy difference. For critical design, use full ASHRAE Manual J or equivalent software.
📐 The Cooling Load Formula – Heat Transfer Fundamentals
The fundamental equation governing heat gain through the building envelope is:
Q = U × A × ΔT
Variable Definitions
| Symbol | Name | SI Unit | Imperial Unit | Description |
|---|---|---|---|---|
| Q | Heat Transfer Rate | W (Watts) | BTU/h | Rate of heat gain through a building element |
| U | Thermal Transmittance (U‑value) | W/m²·K | BTU/h·ft²·°F | Rate of heat transfer per unit area per degree temperature difference |
| A | Surface Area | m² | ft² | Area of the wall, window, roof, or floor |
| ΔT | Temperature Difference | K or °C | °F | Outdoor design temperature minus indoor setpoint |
The total cooling load is the sum of all heat gains: Qtotal = Qenvelope + Qsolar + Qoccupants + Qlighting + Qequipment + Qventilation.
💡 Key Conversion: 1 ton of refrigeration = 12,000 BTU/h = 3.517 kW. This is the amount of cooling provided by melting 1 ton (2,000 lb) of ice over 24 hours. AC units are typically rated in tons or kW.
🌡️ Sensible vs Latent Heat – Two Components of Cooling
Cooling load comprises two distinct components that the air conditioner must handle:
- Sensible Heat Gain: Heat that causes a temperature rise. Includes heat conducted through walls, roof, and windows; solar radiation; and dry heat from occupants, lights, and equipment. The AC removes sensible heat by cooling the air (lowering its dry-bulb temperature).
- Latent Heat Gain: Heat associated with moisture (humidity). Includes moisture from occupants (breathing, perspiration), infiltration of humid outdoor air, and processes like cooking. The AC removes latent heat by condensing water vapor on the cooling coil, which requires additional energy beyond sensible cooling.
🔑 Practical Insight: In humid climates, latent loads can be 20–40% of total cooling load. An oversized AC cools the air quickly (satisfies the thermostat) but runs too briefly to dehumidify properly, leaving the space cold and clammy. Proper sizing is essential for both comfort and efficiency.
The Sensible Heat Ratio (SHR) = Qsensible / Qtotal. Typical SHR values: offices 0.75–0.85, homes 0.70–0.80, restaurants 0.60–0.70 (higher latent from cooking).
☀️ Heat Gain Sources – Where Cooling Load Comes From
External Heat Gains
- Solar Heat Gain (Windows): Direct and diffuse solar radiation entering through glazing. Depends on window area, orientation, SHGC (Solar Heat Gain Coefficient), and shading. Peak solar gain can exceed 600 W/m² of glass.
- Wall & Roof Conduction: Heat conducted through the building envelope when outdoor temperature exceeds indoor. Depends on insulation (U‑value), surface area, and color (dark surfaces absorb more solar radiation).
- Infiltration: Uncontrolled leakage of hot outdoor air through cracks and openings. Adds both sensible and latent load.
Internal Heat Gains
- Occupants: People release 100–130 W each (sensible ~75 W, latent ~55 W for seated activity). More for active spaces (gyms, workshops).
- Lighting: All electrical lighting power ultimately converts to heat. LED lighting: ~10 W/m²; fluorescent: ~15–25 W/m²; incandescent: significantly higher.
- Equipment & Appliances: Computers (50–150 W each), servers (200–800 W), kitchen appliances, copiers, and other electrical devices all contribute to cooling load.
- Ventilation Air: Fresh outdoor air brought in for IAQ must be cooled and dehumidified. This can be a major load component in systems with high outdoor air fractions.
📏 AC Sizing – BTU, Tonnage & Cooling Capacity
Once the total cooling load is calculated, the air conditioner must be sized to match. Key sizing metrics:
| Metric | SI Value | Imperial Value | Typical Application |
|---|---|---|---|
| 1 Ton of Refrigeration | 3.517 kW | 12,000 BTU/h | Base unit for AC sizing |
| Small Room (150 ft²) | 1.5–2.5 kW | 5,000–8,000 BTU/h | 0.4–0.7 ton — bedroom |
| Medium Room (300 ft²) | 3–4.5 kW | 10,000–15,000 BTU/h | 0.8–1.25 ton — living room |
| Large Open Plan (600 ft²) | 5–7 kW | 18,000–24,000 BTU/h | 1.5–2 ton — open office |
| Small House (1,200 ft²) | 8–12 kW | 30,000–42,000 BTU/h | 2.5–3.5 ton |
| Commercial Retail (2,000 ft²) | 15–25 kW | 55,000–85,000 BTU/h | 5–7 ton |
⚠️ Sizing Rule: Size the AC to match the calculated load, not larger. Oversizing by more than 15% leads to short cycling, poor humidity control, and higher energy bills. Undersizing means the space won't cool adequately on design days. Always use a proper load calculation — never guess based on floor area alone.
🏗️ Insulation & Building Envelope – Impact on Cooling Load
Insulation is the most effective way to reduce cooling load. The table below shows how U‑values affect heat gain:
| Construction Type | U‑value (W/m²·K) | R‑value (ft²·°F·h/BTU) | Heat Gain @ ΔT=10°C (W/m²) |
|---|---|---|---|
| Uninsulated Wall | 1.5–2.5 | R-2 to R-4 | 15–25 |
| Standard Insulated (R-11) | 0.6–0.9 | R-9 to R-13 | 6–9 |
| Well Insulated (R-19) | 0.35–0.55 | R-17 to R-21 | 3.5–5.5 |
| High-Performance (R-30+) | 0.2–0.3 | R-28 to R-35 | 2–3 |
| Single Glazed Window | 5.0–6.0 | R-1 | 50–60 |
| Double Glazed Low‑E Window | 1.6–2.2 | R-2.5 to R-3.5 | 16–22 |
🌍 Climate Zones & Outdoor Design Temperatures
Cooling load depends heavily on local climate. ASHRAE defines climate zones with summer design temperatures (the temperature exceeded only 1% of hours in summer). Using the correct design temperature ensures the AC is sized for the worst expected conditions without massive oversizing.
| Climate Zone | Example Cities | Design Temp (°C) | Design Temp (°F) | Cooling Demand |
|---|---|---|---|---|
| Zone 1 – Very Hot | Dubai, Phoenix, Riyadh | 42–48 | 108–118 | Very High |
| Zone 2 – Hot | Miami, Houston, Chennai | 35–40 | 95–104 | High |
| Zone 3 – Warm | Atlanta, Sydney, Shanghai | 32–36 | 90–97 | Medium |
| Zone 4 – Mild | London, Seattle, Paris | 28–33 | 82–91 | Moderate |
| Zone 5 – Cool | Toronto, Berlin, Denver | 28–32 | 82–90 | Lower |
⚖️ AC Oversizing vs Undersizing – The Goldilocks Principle
| Issue | Oversized AC | Undersized AC |
|---|---|---|
| Cooling Performance | Cools space too quickly | Cannot reach setpoint on hot days |
| Humidity Control | Poor — short runtime prevents dehumidification | Better dehumidification (longer runtime) |
| Energy Use | Higher — frequent starts waste energy | Runs continuously, may still be efficient |
| Equipment Life | Shortened by frequent cycling | Normal wear from extended operation |
| Comfort | Cold and clammy; temperature swings | Warm on peak days; steady otherwise |
| First Cost | Higher (larger unit) | Lower (smaller unit) |
🔑 Best Practice: Size the AC to match the calculated cooling load within +0–10%. Modern inverter-driven (variable-speed) ACs can modulate capacity from 30–100%, providing better dehumidification and efficiency even if slightly oversized at full capacity.
📝 Worked Engineering Examples
Example 1: Residential Bedroom AC Sizing
Room: 4m × 3.5m × 2.7m, 2 occupants, 1 double-glazed window (3m²), good insulation, outdoor 35°C, indoor 24°C, 80W lighting, 50W equipment, 15 L/s ventilation.
Wall area (1 exterior wall): 4×2.7 − 3 = 7.8 m². Q_wall = 0.5×7.8×11 = 42.9W. Window conduction: 2.8×3×11 = 92.4W. Solar: 0.5×600×3 = 900W. Occupants sensible: 2×75 = 150W. Internal: 80+50=130W. Total sensible: ≈1,315W. Latent (occupants + ventilation): ≈200W. Total: ≈1,515W = 5,170 BTU/h ≈ 0.43 ton. A 0.5-ton (6,000 BTU/h) window or mini-split unit is appropriate.
Example 2: Open-Plan Office
Space: 12m × 10m × 3m, 15 occupants, 24m² of double-glazed windows, average insulation, 400W lighting, 1,500W equipment (computers, printers), outdoor 36°C, indoor 24°C, 150 L/s ventilation. Total load estimated: ~14,200W = 48,500 BTU/h ≈ 4 tons. A 4–5 ton rooftop unit or split system is required.
Example 3: Small Server Room
Room: 3m × 3m × 2.7m, no windows, 3kW IT equipment, no occupants, good insulation, 20 L/s ventilation. Equipment load dominates: 3,000W sensible. Minimal latent. Total: ≈3,800W = 13,000 BTU/h ≈ 1.1 tons. A dedicated 1.5-ton split AC is recommended for reliability. Redundancy (N+1) is standard for server rooms.
Example 4: Retail Store
Space: 20m × 15m × 3.5m, large storefront windows (40m²), 30 occupants, 2,000W lighting, average insulation, outdoor 38°C, indoor 24°C. High solar + occupancy load. Total estimated: ≈35kW = 120,000 BTU/h ≈ 10 tons. Typically served by 2×5-ton rooftop units.
📊 Cooling Load Quick Reference Tables
Typical Cooling Load per Floor Area by Building Type
| Building / Room Type | W/m² | BTU/h/ft² | Typical AC Tonnage per 1,000 ft² |
|---|---|---|---|
| Residential – Bedroom | 80–110 | 25–35 | 2.1–2.9 |
| Residential – Living Room | 100–140 | 32–44 | 2.7–3.7 |
| Office – General | 90–130 | 29–41 | 2.4–3.4 |
| Office – Conference Room | 120–180 | 38–57 | 3.2–4.8 |
| Retail Store | 100–160 | 32–51 | 2.7–4.2 |
| Restaurant | 150–250 | 48–79 | 4.0–6.6 |
| Classroom | 100–150 | 32–48 | 2.7–4.0 |
| Server Room (per m²) | 300–800 | 95–254 | 8–21 |
| Warehouse | 40–80 | 13–25 | 1.1–2.1 |
Cooling Load Breakdown by Source (Typical Office)
🏭 Common Applications
- Residential HVAC: Sizing split ACs, window units, and central air conditioning for homes and apartments. Bedroom, living room, and whole-house calculations.
- Commercial Offices: Cooling load for open-plan offices, conference rooms, and executive suites. Drives AHU and VRF system sizing.
- Retail & Restaurants: High occupancy and equipment loads require careful cooling calculations. Restaurant kitchens add substantial latent and sensible load.
- Server Rooms & Data Centers: IT equipment dominates the cooling load. Precision cooling with N+1 redundancy is standard practice.
- Healthcare & Clean Rooms: Strict temperature and humidity control with high ventilation rates. Cooling load calculations are critical for compliance.
- Schools & Universities: Classrooms with high occupant density require adequate ventilation and cooling for comfort and cognitive performance.
❓ Frequently Asked Questions – Cooling Load & AC Sizing
Cooling load is calculated by summing all heat gains: Q_total = Q_envelope (walls, roof, windows) + Q_solar + Q_occupants + Q_lighting + Q_equipment + Q_ventilation. Envelope gains use Q = U × A × ΔT. Use our calculator above for automated estimation.
Cooling load is the rate of heat energy that must be removed from a space to maintain desired indoor temperature and humidity. It is measured in BTU/h, kW, or tons of refrigeration. It includes both sensible (temperature) and latent (moisture) components.
As a rough guide, bedrooms need ~25–35 BTU/h per ft², living rooms ~32–44 BTU/h per ft², and offices ~29–41 BTU/h per ft². A 150 ft² bedroom would need approximately 5,000–6,000 BTU/h. Use our calculator for a precise estimate based on your specific conditions.
AC size depends on calculated cooling load. Convert total BTU/h to tons: Tons = BTU/h ÷ 12,000. A 20,000 BTU/h load requires a 1.5–2 ton unit. Never size solely by floor area — always calculate the actual load considering insulation, windows, occupancy, and climate.
AC tonnage is a measure of cooling capacity. 1 ton = 12,000 BTU/h = 3.517 kW. It originated from the cooling provided by melting 1 ton of ice over 24 hours. A 3-ton AC can remove 36,000 BTU/h of heat from a space.
Sensible heat is the heat that causes a change in temperature without changing moisture content. It includes heat conducted through walls, solar radiation, and dry heat from occupants and equipment. The AC removes sensible heat by lowering air temperature.
Latent heat is the energy associated with moisture (humidity). It's released when water vapor condenses. Occupants add latent heat through breathing and perspiration (~55W/person). The AC removes latent heat by condensing moisture on the cooling coil.
Better insulation (lower U‑value) reduces heat conduction through walls and roof, directly lowering cooling load. Upgrading from poor insulation (U=1.5) to good insulation (U=0.5) can reduce envelope heat gain by two-thirds. Insulation is the most cost-effective way to reduce AC size and energy bills.
High cooling loads are caused by: large unshaded windows, poor insulation, high outdoor temperatures, many occupants, high-wattage lighting and equipment, excessive ventilation air, and air leakage. South- and west-facing windows contribute disproportionately to solar heat gain.
An oversized AC cools the space too quickly, short-cycling (frequent on/off). This leads to: poor dehumidification (cold and clammy air), higher energy bills (startup surges), wider temperature swings, increased wear on the compressor, and reduced equipment lifespan.
An undersized AC cannot maintain the setpoint temperature on hot days. It runs continuously but still can't keep up, leading to discomfort. While it dehumidifies well (long runtime), the space remains warm. In extreme cases, the compressor may overheat from continuous operation.
Hotter climate zones require larger AC systems because the outdoor-to-indoor temperature difference (ΔT) is greater, increasing envelope heat gain. A home in Phoenix (design temp 43°C) needs significantly more cooling capacity than the same home in Seattle (design temp 30°C).
Solar heat gain is the heat entering a space through windows due to solar radiation. It depends on window area, orientation, SHGC (Solar Heat Gain Coefficient), and shading. Peak solar irradiance can exceed 800 W/m². Low‑E coatings and external shading significantly reduce solar gain.
Calculate each heat source: envelope (Q=U×A×ΔT for walls, windows, roof), solar gain through glass, internal gains (occupants ~100W/person, lighting, equipment), and ventilation/infiltration loads. Sum all sensible and latent components for total cooling load. Our calculator automates this process.
Split AC sizing depends on room cooling load. For typical residential rooms: 1 ton (12k BTU) for up to 150 ft²; 1.5 ton (18k BTU) for 150–250 ft²; 2 ton (24k BTU) for 250–400 ft². These are rough estimates — use our calculator for a proper load-based sizing.
Humidity adds latent cooling load. The AC must condense moisture from the air, which requires additional energy beyond sensible cooling. In humid climates, latent load can be 20–40% of total load. The AC coil must be cold enough to reach dew point and condense water vapor effectively.
HVAC cooling capacity is the maximum rate at which an air conditioning system can remove heat from a space, expressed in BTU/h, kW, or tons. It's the nameplate rating of the equipment. Actual delivered capacity varies with indoor and outdoor conditions.
The basic formula is Q = U × A × ΔT for envelope loads. Total cooling load = Σ(envelope gains) + solar gains + internal gains + ventilation load. Internal sensible gain from occupants: ~75W/person seated. Equipment: sum of all electrical wattage. Lighting: total wattage. Ventilation load depends on outdoor air enthalpy.
Typical cooling loads per square foot: residential 25–44 BTU/h/ft²; office 29–41 BTU/h/ft²; retail 32–51 BTU/h/ft²; restaurant 48–79 BTU/h/ft². These are guidelines only — actual load depends on insulation, windows, occupancy, climate, and internal gains.
Tons = BTU/h ÷ 12,000. For example, 36,000 BTU/h = 3 tons. To convert kW to tons: Tons = kW ÷ 3.517. These conversions are essential when selecting AC equipment from different manufacturers who may use different rating units.
Heat gain is the instantaneous rate of heat entering a space. Cooling load is the rate at which heat must be removed by the AC system. They differ because some heat gains are absorbed by building mass (thermal storage) and released later. Cooling load calculations account for this time delay.
East-facing windows receive peak solar gain in the morning; west-facing windows peak in the late afternoon (often the hottest part of the day). South-facing windows (northern hemisphere) receive consistent moderate gain. North-facing windows receive the least direct solar gain. West-facing windows are often the most problematic for cooling.
ACCA Manual J is the ANSI-recognized standard for residential cooling and heating load calculations in the US. It provides detailed procedures for calculating room-by-room loads considering all heat gain sources. Many building codes require Manual J calculations for HVAC equipment sizing.
Ventilation load = airflow × ρ × (h_outdoor − h_indoor), where h is enthalpy (kJ/kg). It includes both sensible and latent components. For approximate calculations: sensible = 1.23 × L/s × ΔT (Watts); latent = 3.0 × L/s × ΔW (Watts), where ΔW is humidity ratio difference in g/kg.
The U‑value (thermal transmittance) measures how easily heat passes through a building element. Units: W/m²·K (SI) or BTU/h·ft²·°F (Imperial). Lower U‑value = better insulation = less cooling load. Typical U‑values: uninsulated wall 1.5–2.5, well-insulated wall 0.3–0.5, double-glazed window 2.5–3.0.
Higher ceilings increase room volume, which increases the amount of air that must be cooled and can lead to thermal stratification (warm air rises). While wall area (and thus envelope load) remains the same, the increased volume affects ventilation requirements and may require higher airflow rates for proper air distribution.
SHGC (Solar Heat Gain Coefficient) is the fraction of solar radiation admitted through a window. Range: 0 (no solar gain) to 1 (all solar radiation passes through). Single clear glass: SHGC≈0.8; double-glazed Low‑E: SHGC≈0.3–0.5. Lower SHGC = less solar cooling load. It's a critical metric for window selection in cooling-dominated climates.
All electrical power consumed by lighting ultimately becomes heat. LED lights convert ~90% of input power to heat (the rest to visible light, which also becomes heat when absorbed by surfaces). However, LEDs use 75% less power than incandescent for the same light output, proportionally reducing cooling load.
Server room cooling load is dominated by IT equipment. A typical server rack consumes 3–8 kW, all of which becomes heat. For a small server room with 3kW of IT equipment, total load is ~3.5–4.5 kW (12,000–15,000 BTU/h, ~1–1.25 tons). Always include redundancy (N+1 or 2N) for critical IT environments.
Commercial cooling load uses the same principles as residential but accounts for higher internal gains (more occupants, lighting, equipment), larger ventilation requirements, and diverse space types. ASHRAE's Heat Balance Method or Radiant Time Series (RTS) method are standard. Software like Trane TRACE, Carrier HAP, or IES VE is commonly used.
The design outdoor temperature is the temperature exceeded only 1% of annual hours (ASHRAE 1% design condition). It ensures the AC can maintain comfort during all but the very hottest hours. Using the absolute record high would oversize the system for normal conditions.
Light-colored (cool) roofs reflect more solar radiation (high albedo), reducing roof surface temperature by 20–30°C compared to dark roofs. This significantly reduces heat conduction through the roof into the space below. Cool roofs are an effective passive cooling strategy in hot climates.
SHR = Sensible Load / Total Load. It indicates what fraction of cooling is for temperature reduction vs. dehumidification. Typical SHR: offices 0.75–0.85, homes 0.70–0.80. AC coils are selected to match the space SHR. A mismatch means the coil either over-dehumidifies or under-dehumidifies the space.
Inverter (variable-speed) ACs can modulate capacity from ~30% to 100%. This makes them more forgiving of slight oversizing because they can run at lower capacity for better dehumidification and efficiency. However, they should still be sized to match the calculated load for optimal performance and cost.
Total capacity includes both sensible and latent cooling. Sensible capacity is the portion that lowers air temperature. Equipment specs list both. An AC rated at 36,000 BTU/h total with SHR=0.75 provides 27,000 BTU/h sensible and 9,000 BTU/h latent cooling. Ensure both capacities meet your calculated loads.
Typical occupant heat gain for seated office work: 115–130W total per person (sensible ~70–75W, latent ~45–55W). For light activity: ~150W. For moderate activity (walking): ~200W. For heavy work (gym): 300–500W. Multiply per-person values by number of occupants for total occupant load.
Infiltration is the uncontrolled leakage of outdoor air into a building through cracks, gaps, and openings. It adds both sensible and latent cooling load. Infiltration rates depend on building tightness, wind speed, and indoor-outdoor temperature difference. Modern well-sealed buildings have infiltration rates of 0.1–0.3 ACH.
Building orientation affects solar exposure. In the northern hemisphere, south-facing façades receive the most total daily solar radiation; west-facing façades receive intense late-afternoon sun that coincides with peak outdoor temperatures. Proper orientation, shading devices, and window placement can reduce cooling load by 20–30%.
Classrooms have high occupant density (~30 students + teacher), requiring significant ventilation (5–7 ACH). Typical cooling load: 100–150 W/m² (32–48 BTU/h/ft²). For a 60 m² classroom, this equates to 6–9 kW (20,000–30,000 BTU/h, ~1.7–2.5 tons). Proper ventilation cooling load is a major component.
For most electrical equipment, the cooling load equals the power consumption (all electricity ultimately becomes heat). Use nameplate wattage for simple loads. For motors in the space, use the motor efficiency to determine heat output. For intermittent equipment, apply a usage diversity factor (e.g., 0.5 for occasionally used devices).
Cooling load is the rate of heat that must be removed from a space; heating load is the rate of heat that must be added. Cooling load includes solar gain and internal gains (which help offset heating load). The same building typically has a different cooling load than heating load due to these factors.
Ducts running through unconditioned spaces (attics, crawl spaces) gain heat from the surroundings, increasing the effective cooling load. Add 10–30% to the calculated room load to account for duct gains, depending on insulation and location. Ideally, ducts should be within the conditioned envelope to minimize these losses.
Common rules of thumb: 1 ton per 400–600 ft² for residential; 1 ton per 250–400 ft² for commercial; 1 ton per 100–200 ft² for server rooms. However, rules of thumb are notoriously inaccurate and can lead to significant oversizing. Always perform a proper load calculation for final equipment selection.
At higher altitudes, air density decreases, which reduces the mass flow of air for a given volumetric flow. This affects both heat transfer at coils and ventilation loads. Cooling load calculations at altitude should use actual air density. Equipment capacity also derates with altitude — manufacturer correction factors should be applied.
Professional HVAC engineers use specialized software: Carrier HAP (Hourly Analysis Program), Trane TRACE 700/3D Plus, IES Virtual Environment, DesignBuilder (EnergyPlus), and Elite CHVAC. For residential, ACCA-approved Manual J software like Wrightsoft Right-J or Adtek AccuLoads. Our calculator provides a simplified estimate for quick sizing.
Room dimensions alone are insufficient for accurate BTU calculation. You need: wall/window areas, insulation levels, outdoor design temperature, indoor setpoint, occupancy, lighting, and equipment. As a very rough estimate: multiply floor area (ft²) by 25–40 to get BTU/h. Our calculator uses a more detailed method considering all these factors.
Residential kitchens have high cooling loads due to cooking appliances. A typical residential kitchen may need 5,000–12,000 BTU/h of additional capacity beyond the base room load. Commercial kitchens require specialized ventilation and cooling: 150–250 W/m² (48–79 BTU/h/ft²). Always include a dedicated makeup air system for commercial kitchen exhaust.