How buying AC

In this AC buying guide, our goal is to save money as much as possible on the initial and running cost of an air conditioner. We will explain how to pick the right air conditioner for your home in simple 7 steps. We understand that finding a great AC is not an easy task, mainly because this appliance costs an extra monthly bill, if not selected properly.

There are multiple factors that you need to understand before buying your first AC. Here are the recommended 7 steps to follow

Decide your budget
Select the AC Type
Check your Room Size
Look for better star rated AC
Check for AC condenser coil type
Go with inverter technology
Look for additional important features

Step 1: Decide your Budget

The first step before buying anything is, of course, to decide your budget. In the case of AC, the more price you pay initially, the running cost will be substantially less. For example, purchasing a 5 star AC will definitely cost you more, but it will save more electric power, which is also a part of saving. With a high budget, you get the latest technology like inverter AC that has a 5 to 10 years longer lifespan. Furthermore, high budget AC comes with low maintenance costs. So, carefully decide your budget before you buy it.

Step 2: Select AC Type

Always understand that your requirement decides which AC type you need. So there are basically two types of AC available in the Indian market, i.e., Split AC and Window AC. So, here is how you can decide which AC type your home required.

Why You Need Split AC?

Split ACs are generally expensive than a window AC but comes with better cooling efficiency. Don’t get us wrong here, it all depends on Bee star rating but typically split AC is slightly more efficient as the suction and blower area of the window AC is comparatively smaller in size. Here are some points why you should select split AC.

If your medium-sized room faces direct sunlight
If you want to place your ac to your favorite place
If you need super silent air conditioning in your room
Choose split inverter AC if you are going to use AC for more than 5 hours every day

Why You Need Window AC?

Window AC comes with 20% less price than a split AC having same star ratings and also saves more power. Window AC requires a window in your room in order to install it. Here are some more valid points to pick a Window AC instead of Split AC.

If you have small to medium size room
If you need non-complex installation without drilling in your wall
If you need super quick installation and uninstallation

Fun Fact: You barely can hear the compressor noise of a Split AC as it stays outside of your room. However, you can hear the noise of Window AC’s compressor clearly. Also, there is a misconception that the split AC compressor that stays outside can get damaged by rain. However, it’s not true. The compressor of split AC is built for the outdoor environment; even though, try to keep it dust-free.

Step 3: Check Your Room Size

Okay, now you have decided which AC type you need, the next step is to check your room size. You ask why? Because room size helps us to pick the correct tonnage (capacity in ton) limit.

If you select too much higher AC tonnage for your room, you will end up paying the expensive monthly bills. Alternatively, if you select lower AC tonnage, then you won’t get sufficient cooling in your room which is again a wastage of money.

For example: If you choose 1.5 ton AC in an 8 x 8 feet room then it will cause more power consumption. In such a scenario, having a 1-ton capacity AC is a better choice for optimal cooling and power saving. Remember, the goal is still to save our money.

Choose AC Tonnage According to These Room Sizes

8 x 10 feet room size = 0.8 ton AC
10 x 10 feet room size = 1 ton AC
12 x 15 feet room size = 1.2 ton AC
14 x 15 feet room size = 1.5 ton AC
20 x 20 feet room size = 2 ton AC

Read more about calculating AC tonnage for your room.

Fun fact: Try to face your AC in the East or North direction for optimal cooling in India. The cooling also depends on the floor on which you are installing an AC (higher capacity AC for the higher floor). If the window of the room is too large or the atmospheric temperature is above 38°C, you may require a high-capacity AC.

Ton Calculation Formula: If your room has a typical height of 10 feet then use this method. Check the length and breadth of your room carefully and follow this formula.

Suppose your room size is 12 feet wide and 15 feet long
So overall size is 12 x 15 = 180 Sq. Ft.
Now take the square root of 180 = 13.4
Finally, divide it by 10 = 1.34

Step 4: Look for Better Star Rating

Star rating is given by BEE (Bureau of Energy Efficiency) which is an Indian government “Department of Energy Saving”. So this star rating is totally based on ISEER value (Indian Seasonal Energy Efficiency Ratio). Its ISEER value simply tells how efficiently an appliance is using electricity. In other terms, it means that your AC is using only the necessary amount of power to produce required cooling. Higher the value of ISEER means less wastage of electricity.

According to this chart, if an AC has a 4.55 ISEER value, it should be a 4 Star AC. However, the star rating may change if the ISEER value is older than in 2018. Learn more about star rating in AC.

As a conclusion, we can say that AC consumes less power when it has a high energy star rating. Below is the chart of monthly saving on 1-star to 5-star energy star ACs. This chart is a rough figure for your monthly bill savings, assuming that you run your AC for 8 hours daily.

Fun Fact: Window AC with same star rating as Split AC, generally are less efficient. For the sake of simplicity, just remember that a 3-star window AC saves typically as much power as a 2-star split AC.

Meaning and Objective of BEE Star Rating

BEE star rating means how efficiently an appliance can use electric power. It is represented in the simplest form of a star rating given out of 5. The more the star rating of an AC, the less energy it will consume power, and you will save more electricity bills.

So it should be easy to understand that a 4-star inverter AC will save more power than a 3-star inverter AC. So always try to purchase a high BEE star rating AC like 4 stars or 5 stars. We also know that a 5-star inverter AC will cost more than a 3-star inverter AC, but the 5 star AC will save huge money on electricity every year. So effectively, a better eco-friendly investment would be a 5 star AC rather than a 3 star AC.

1. EER Value

EER stands for Energy Efficiency Ratio and is generally given to the fixed speed compressor (non-inverter) Air conditioners. EER of an AC is defined as

EER = Amount of heat removed in an hour ÷ Power consumed in the same hour

The heat removed by the AC will depend upon the temperature of the room. Therefore, it is calculated at a particular temperature and humidity. Generally, the outdoor temperature is set to 35°C and the indoor temperature will be set to 27°C with 50% of the humidity value for calculation purposes.

2. ISEER Value

After the introduction of variable speed air compressor conditioners (inverter AC), the old calculation method was not enough to provide an accurate result for different ACs. In fact, BEE has to introduce a new system of value calculation i.e. ISEER (Indian Seasonal Energy Efficient Ratio).

ISEER = Cooling Seasonal Total Load (CSTL) and Cooling Seasonal Energy Consumption (CSEC).

As you can see, the calculation method of ISEER is pretty much the same as EER, but ISEER also considers the seasonal temperature changes and the variable power consumption by an inverter type AC.

3. Difference Between ISEER and EER

So we can say that all the non-inverter (fix speed) ACs will have EER value whereas the inverter ACs will have ISEER Value. Now, these values lead us to the BEE Star ratings. Take a look at the example below.

Example of EER Value and Star Rating of a 1.5 Ton Non-Inverter Split AC

ISEER and Star Rating of 1.5 Ton Air Conditioner

From this image, we can easily understand that if a 1.5 tonnage capacity non-inverter split AC has a 3.3 EER value, that means it will have a 4 Star rating in the year 2020 – 2021. Also, it will consume approximately 1576 Watts of electricity per year and will save around 2400 per year.

Step 5: Condenser Coil Type

Every AC has a condenser coil inside the body in which a refrigerant flows. Refrigerant requires better heat exchange (conductivity) within the coil so that AC can perform fast and consistent cooling. That is why we have to choose better material for the condenser coil.

The straightforward answer to this is to choose copper material. Always prefer copper condenser coil type over aluminum type because of its better property of conductivity. The copper coil is more heat transferable, efficient, high in performance, running cost, and lifespan. The copper coil is also corrosion resistance, easy to maintain, and repairable. So without a second choice, choose copper coil type in your AC to enjoy the optimal cooling performance for years.

Step 6: Go with Inverter Type AC (Optional)

What type of compressor technology does the AC use, inverter or non-inverter? You see, inverter AC has significant advantages over non-inverter AC but it is a little costly. Let us understand the primary benefits of using inverter AC.

Constant cooling: Inverter type AC gives you consistent cooling performance under extreme weather. It will maintain your room temperature and keep it steady.
Quick cooling: If you want rapid cooling under 5-6 minutes, you should consider choosing an inverter type AC over a non-inverter type AC. The speed of the inverter-type AC compressor varies with the temperature of your room.
Less noise and uses optimal power: It’s the primary advantage of having an inverter type AC that it uses less energy to perform efficient cooling and remains less noisy.
Long compressor life: Due to less load on your inverter type compressor, the age of your compressor is long-lasting for sure.
Save more bill: The inverter compressor doesn’t start or stop the rotary motor automatically, which saves the power to start the compressor again and again. Instead, the inverter compressor simply changes the motor speed as per outdoor temperature. Due to this reason, inverter ACs end up saving 20% bill more bills annually.

Step 7: Cross-Check these Additional Features

Advance Air-conditions (AC) comes with additional features that are very helpful other than cooling.

Noise level: Always check if the AC is quiet or not. A noise level of max 44 dB can be considered silent.
Economic Mode: It is a simple yet useful feature that saves power by reducing undesired cooling in the room. Check if your AC has one.
Anti-Bacteria Protection: Some AC can remove harmful bacteria and micro-organisms to keep the airflow healthy.
Auto-Off Timer: The majority of AC has the function to turn on the auto sleep timer from the remote (saves power).
Dehumidification: On sweaty days, a good AC can dehumidify the moisture present in the air to make it more suitable for the human body. Always consider buying an AC with this feature, especially in India.
Wifi Control: Wifi-control allows you to turn off or on your AC from any destination. You just have to connect your AC to the Wi-Fi internet connection to use this feature.