CategoriesAir Conditioner

How To Calculate What Size Of window AC you Need For Your Room in Noida

window ac according to room size (1)

Calculating the appropriate size of a window air conditioner (AC) is crucial to ensure optimal cooling and energy efficiency in a room in Noida

Several factors need to be considered when determining the AC size  as per the Noida’s climate, including the room’s square footage, insulation, sun exposure, number of occupants, and more.

This guide will provide you with step-by-step instructions on how to calculate the size of a window AC unit.

Determine the square footage of the room:

Measure the length and width of the room in feet, and multiply these two numbers together to get the square footage.

1.       For example: if the room is 12 feet long and 10 feet wide, the square footage would be 120 square feet.              

air conditioners 2023 as per your room size
Air Conditioners according to Room Size
Consider the room’s insulation:
Insulation plays a significant role in maintaining the desired temperature within a room.
If the room is well-insulated with proper sealing and insulation materials, you can use the basic calculation.

However, if the room has poor insulation or is exposed to direct sunlight, adjustments need to be made.

Adjustments for insulation and sun exposure:

 If the room is poorly insulated or has significant sun exposure, you will need to adjust the cooling capacity accordingly.

Use the following guidelines:

1. Poor insulation: Increase the capacity by 10-15%.

2. Direct sunlight exposure: Increase the capacity by 10%.

3. Very sunny room or kitchen: Increase the capacity by 15-20%.

Consider the number of occupants: The number of people occupying the room can contribute to the cooling load.

Add 600 BTUs (British Thermal Units) for each additional person beyond two people.

For example, if there are four people in the room, add 1,200 BTUs to the cooling capacity.

Calculate the cooling capacity:

 The cooling capacity of an air conditioner is measured in BTUs per hour.

The general rule of thumb is to have 20 BTUs per square foot of space.

Multiply the square footage of the room by 20 to calculate the base cooling capacity.

For instance, if the room is 120 square feet, the base cooling capacity would be 2,400 BTUs.

Make adjustments for insulation and sun exposure:

 Refer to the adjustments made in step 3 and add or subtract the appropriate BTUs from the base cooling capacity calculated in step 5.

Determine the appropriate AC size:

 Air conditioners come in various sizes, typically ranging from 5,000 BTUs to 25,000 BTUs.

Select an AC unit with a cooling capacity that closely matches or slightly exceeds the calculated cooling capacity from step 6.

If the calculated cooling capacity falls between two available AC sizes, it is generally recommended to choose the larger size for optimal cooling efficiency.

Remember, these calculations serve as a general guide, and other factors such as room shape, ceiling height, and the presence of heat-generating appliances may require further adjustments.


It’s always best to consult with an HVAC professional for an accurate assessment, especially for complex scenarios.

By following these steps, you can calculate the appropriate size of a window AC unit for your room, ensuring efficient cooling and enhanced comfort.


In Noida, the appropriate capacity for a window AC would depend on the room size and the temperature conditions. However, as a general guideline, for a small room up to 150 square feet, a window AC with a cooling capacity of around 5,000 to 6,000 BTUs should be sufficient. For larger rooms, you may need to consider higher capacities, such as 7,000 to 9,000 BTUs. It is recommended to consult with an HVAC professional for a more accurate assessment based on your specific requirements.


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