How to calculate AC tonnage for your projects

Summers setting in, and it’s time to bring out those AC’s, and a lot of us will be out looking for new AC’s this season.. Shopping for the right kind of air conditioner can be quite confusing, and a lot of times we can be misled into buying a larger unit than required or worse than that, buying something which is too small for our room!
It is important to have some idea about how to calculate the AC capacity that you require for your room… which depends not only on the size of the room but also on the size of the windows, which direction they face, number of people who occupy it, the insulation of the room (is it on the top floor or in the basement) even the wattage of equipment in the room influences the required AC capacity (more relevant for offices).

The most basic thumb rule to get started is to calculate the volume of your room in feet and divide it by 1000, this will give you the required capacity in TR (tons). So a 10 foot by 10 foot room which is 10 feet high will need a one ton AC (10’x10’x10’ = 1000 Cu.ft. / 1000 = 1 ton).

But to add some precision to this calculation do the following:

Measure the dimensions of your room.
Identify the orientation of your windows and measure their sizes (don’t add up the window sizes as a north facing window impacts the calculation different from a south facing window)

Follow the link below and use the AC tonnage calculator provided by companies like carrier to get a the required tonnage for your room (more calculators can be found online)

Link to calculator

After this let’s understand the units. One ton (TR) of refrigeration refers to the heat extraction capacity of the unit, it’s an American unit and equates to the amount of energy required to melt one short ton of ice (about 907 KG or 2000 pounds). This is equivalent to 12000 BTU/h (British thermal unit), beware of products that claim to be a one ton unit but have a cooling capacity of less than 12000 BTU. Finally we need to check the power consumed by the unit in watts and the star rating which is based on the EER (energy efficiency ratio). If we convert the cooling capacity to watts (1 ton = 12000 BTU = 3517 watts) and then divide it by the power consumed to achieve this we get the EER, the higher the better (this shouldn’t ever be below 2.3 and should be around 3.5 for a 5-star rating).

So to summarize:
Calculate the cooling capacity (in TR) based on your room requirements
Check the cooling capacity (in TONS as well as BTU then convert it to watts)
Check the power consumed.
Check the BEE rating. (verify by dividing cooling capacity by Power consumed)

Updates 6 feb 2019:

If you found the above article useful and are looking to go out and buy a new AC this season, here’s an update on the latest innovations in Air conditioning technology that you might want to look out for.

Cloud enabled AC control 

Imagine being able to turn your AC on 15 minutes before you reach home. AC’s with cloud control are here, these AC’s connect to the internet through the WiFi system of your home and are easily controllable through an app.

Please note: Cloud connectivity is different from WiFi connectivity, where appliances are controlled by devices within the Wifi network, the main difference being that a cloud based AC will allow you to control the AC from anywhere.

Check out brands like Lloyd and LG for options with this feature

Reverse cycle 

Here’s another innovation that’s been around for a few years but has been gaining traction recently. Reverse cycle AC’s come equipped with heat pumps so that you can convert your AC into a heater in the winter. These systems are perfectly suited for winters where the temperatures don’t fall below freezing. No more evenings spent huddling around the blower, this is an energy efficient way to keep your home nice and cozy.

Recommended brand for reverse cycle: Daikin

Do leave your questions and comments and if your looking for a home renovation visit us at to get a free estimate.

Home Hacks that you would love

    Many a times, you don’t get the opportunity nor do you have the budget to give your house a complete makeover. But here are some things you could look into, for a better utilization of space.


1) Creating zones in your living room

    Many houses have large dining cum drawing areas, and lesser personal space. With the result, the TV has to be placed in the drawing room (read: living room) itself. Thus making it a ‘Den’, like the Americans call it. However, if you have some extra space, and don’t really want to partition the areas, you could use different flooring as a demarcation. Your living space could have a wooden laminate, and the formal area could have an off-white tile/ marble flooring or could be carpeted.
You could also create a small step to separate the areas.
Another way of creating zones could be different lighting.

2) Space hacks in Bedrooms

    A lot of times, Bedrooms are so small that there is barely enough space round the bed, to walk around. One Space hack could be, to create a thin vertical rack on the bed sides, instead of bed side tables, to stack books or other utility/decorative items.


3) Making Bathrooms look larger
    One of the best ways to make a small bathroom look larger, is to install a large horizontal (or full length if you may) mirror, on the wall without any fittings.

You may also want to add a dimmer to your light fittings, to make it feel larger.

The Chronicles of Getting Anything Built or Renovated, Ever!

Anyone who has been through the building process would know how tough it is to get anything built or renovated, it’ll cost you more than it should and take forever!!

The hassles one has to go through to choose the right products for his or her project leads to price insecurities and cause many people heart ache, very often straining the client-designer relationship and upsetting the overall health of the project. Being an architect, I meet such hassled customers day in-day out. And hence, the idea of ‘BuildingBlox’ was born. Well no, we don’t make construction blocks, but what we are working on is a virtual expo of building materials. In its current form ‘BuildingBlox’ is a gallery of construction products that will come in handy while constructing or renovating any space, very soon we will expand our horizons to professionals and retailers to create a more robust platform.

The idea behind the portal is to help you reduce those material sourcing trips to the market, and to reduce your dependence on the contractor’s suggestions. We strive to give you the power to research materials and products in the comfort of your room.

We are steadily increasing the product directory and hope to make it a one stop shop for all your construction and design needs, in the interim, we hope you like what you see:

Also watch this space for everything related to design and construction, with posts relating to new and innovative products, material quantity calculators, ‘Do It Yourself’ tips and loads more!