To calculate the room air conditioner capacity required, a simple rule of thumb can be applied and accordingly, you need to multiply the area by 120BTU per square foot to get the minimum BTU of air conditioner you should buy,

Area Calculated earlier: 180 sq.ft.

(1 Square foot = 120 BTU)

Minimum BTU of Air Conditioner = 180 x 120 = 21600BTU

21600BTU cooling capacity will be required for this room size. Air conditioner cooling capacity is also defined in terms of Tonnage (Tr). (1Tr =12000 BTU) So, here for a given room size, the air conditioner requirement will be of

Tonnage = 21600/12000 BTU = 1.8Tr

It can be said that a 1.0 Tr capacity air conditioner is needed for cooling if the space is 100 sq ft in size and has a normal height

The number of people in the room, glass windows, exposed walls, the roof, the ceiling, building orientation, the height of the room, and any insulation that may be present are all factors that should be considered while determining the appropriate size of the room air conditioner.

Compressor Technology: Whether you would benefit more from a fixed-speed compressor technology or a DC inverter compressor-based air conditioner should be taken into consideration while determining what kind of air conditioner to invest in for your home or business. These are the two primary compressor technologies for room air conditioners, so it’s important to know how they differ in terms of functionality, energy efficiency, and performance.

Room air conditioner with Fixed speed compressor

Fixed speed air conditioners, which are also referred to as non-inverters, are designed with a single-speed compressor motor that can be either fully running or completely off. This implies that the compressor motor turns off soon after the desired temperature in the room has been reached and restarts when temperatures rise above a predetermined threshold. In other words, fixed-speed air conditioners are either completely off or 100% working.

Room air conditioner with Inverter compressor

The cooling capacity of air conditioner built with Inverter type compressor is modulated according to the demands of room temperature conditions through a variable frequency drive, also known as an inverter drive.

Contrary to the start/stop operation of a fixed speed air conditioner, inverter air conditioners use variable-speed motor technology within the compressor and can adjust the compressor speed in response to changes in room temperature. As a result, when the air conditioner achieves the desired room temperature, it operates in a lower speed that keeps the compressor motor running rather than turning it off & thus maintaining a constant room temperature and enhancing indoor comfort.

In addition to having a larger start-up surge, a fixed speed compressor will continue to consume the same amount of energy while it is running, regardless of the room temperature condition. When less output is needed, a variable speed or inverter compressor will reduce its RPM; when more is needed, it will ramp them up.

Energy labeling: The star rating labels that have been regulated by the Bureau of Energy Efficiency, a government undertaking body in India, are used to determine the energy efficiency of air conditioners. Star ratings range from 1 Star to 5 Star, with 5 Stars being the highest efficiency band. Customers can purchase air conditioners with 3 Star energy rating bands for moderate usage while 5 Star energy rating bands are more effective in terms of conserving electricity as well as operational costs.

Consider the climate: The right size of air conditioner is dependent in part on the climate of the region in which you live. For more effective cooling in hot and humid climates, you may need a larger unit.

Once you have determined the BTU that is appropriate for your space, choose an air conditioner that is appropriate in size. Additionally, there are several different capacities of air conditioners, ranging from 9000 BTUs (0.75 Tr) for a small room to 37,200 BTUs (3.1 Tr) for a large area. Choose an air conditioner that has the capacity to cool your room the closest.

The indicative room air conditioner capacity required for cooling a room is shown in the following chart.

For optimal performance, it’s essential that you choose the right air conditioner and have your appliance professionally installed.

In conclusion, choosing the right air conditioner depends on factors like the size of your space, climate conditions of your region, indoor heat load, energy labeling, how reliable is the brand, and offerings in terms of innovative technologies or features. Choose an air conditioner that is the right size for your space; otherwise, it may not be able to effectively cool the room. Additionally, selecting an air conditioner with a larger capacity than what is needed for your space may result in increased energy costs and initial costs.