AC Buying Guide, 15 MUST KNOW aspects before buying

5
(3)
1.2k
SHARES
7.7k
VIEWS

Content Summary - Click on the link for quick read

5
(3)

Goal of this AC Buying Guide is to give complete info about sizing, buying, installing & maintaining ACs and help to identify right AC from numerous options available. This AC Buying Guide outlines the 15 aspects that you must consider when buying and installing an AC.

Once you read this post, recommended to read the related posts given below as all these posts together cover the entire information regarding home interior readiness. 

AC Buying Guide – Aspects to be considered for AC selection & maintaining

Different types of Air Conditioners based on physical nature & installation methods

  1. Window AC
    1. Advantages – One indoor unit to install. Transportation and maintenance are easy.
    2. Disadvantages – Need provision in the window for smooth installation, few options available to choose.
    3.  
  2. Split AC
    1. Advantages – Silent operation compared to Window AC, Aesthetically better than Window AC.
    2. Disadvantages – Need provision in the window for smooth installation, Indoor & Outdoor units to install. Professional support need for install or de-install.
    3.  
  3. Portable AC
  4. Other AC types like cassette AC, Centralized AC using VRVs etc. These ACs are mainly used in commercial scenario and not covered in this post.

Why select Split AC over Window AC?

Better to go for Split AC (costlier & complex installation/shifting) in comparison to Window AC (cheaper & easy installation/shifting) due to the following reasons.

  1. Silent in operation.
  2. Aesthetically better & can install majority of the places
  3. Will not obstruct the air & light by taking space in the Window (if special provision on wall is not there)
  4. More energy efficient models across all brands will be available
  5. Higher capacity (Above 2 ton) options available.
  6. No difference in power consumption.

What provision is needed for installing the Split AC?

  1. Split AC need clear path to route 2 copper pipes up to the Outdoor AC. By default, most brands supply the copper pipe free or on chargeable basis along with new AC. When Outdoor unit is positioned longer than 4 meters, additional pipe need to be added on extra cost.
  2. Spilt AC indoor unit need to discharge the water accumulated and need to route a pipe from indoor to the drain line. Must ensure that drain pipe having natural slope for water to flow normally. If the slope is not properly maintained, water will be dripping inside room when the collection tray inside indoor overflows. So have the hole to route the A/C gas and water pipeline in a slope. If the hole provided on the wall by Builder not allowing the slope to water pipe, get a new hole made to route the pipe.
  3. Drain pipe to connect to the Building’s drain line for proper draining of the drain water.
  4. Both Indoor and Outdoor must be installed on a strong wall using the L-angle or a platform.

AC based on Technology Type – Inverter AC or Conventional AC

  1. Inverter AC – The input AC power is converted to DC power using a rectifier and then again converted to AC power of desired frequency to drive the motor. Since frequency of the alternating current (AC power) and the speed of induction motor are directly proportional, the compressor speed can be altered as required.
  2. For quick cooling, it will run at high speed when an INVERTER air conditioner is started. But once the set temperature is reached, by lowering the compressor speed, the INVERTER air conditioner enters an’ energy saving mode.’ Thus, reducing its energy efficiently to save energy.
  3. Regular AC – To maintain the set room temperature, it uses fixed speed compressors to automatically start or stop. This means that either full or no capacity is operated by fixed speed systems. This on and off cycle, as you may have guessed, causes unnecessary electricity wastage and does not maintain constant room temperature. Since controlling the compressor is not required, it uses fewer parts and is therefore cheaper than inverter AC for one-time cost & maintenance.

Why select Inverter AC over non-inverter AC? – Best AC by technology

If you can little extra money, please go for Inverter AC. The running cost is at least 35% less than regular ACs which will adjust the extra amount spend initially. Although sales representatives may say that Inverter AC is good only when continuously run, but that is not the case if you use AC for at least 6 to 8 hours in 24 hours.

Precautions to be taken when buying Copper pipes?

(Copper pipe not provided with AC by manufacturer or need extra pipe to extend the pipe?)

  1. When you buy pipes, ensure that the both Copper pipes MUST have thickness of 0.8mm (minimum) or 1mm. This is very important especially when you use R410A gas (majority of the ACs) because of high pressure of the gas flow.
  2. Refer the Technical Specification of the AC you bought to see the manufacturer recommended diameter of the Gas Pipe. Observed that it varies between brands as well as Type of the AC. Eg. O’General 1.5 ton INVERTER 5 Star AC need ½ IN, ¼ IN and5 Ton REGULAR 3 Star AC need 5/8 IN, ¼ IN.
  3. Ensure that joints are insulated using the insulation materials supplied along with AC or bought by the authorized installer.

What is the ideal capacity of the AC to buy?

Typical AC tonnage requirements when the room is of 9 to 10 feet height is given below.

If Area of 80 Sq. Ft. to 130 Sq. Ft. – 1-ton AC = 12000 BTU = 3517 watts of cooling  

Area of 130 Sq. Ft. to 196 Sq. Ft. – 1.5 ton = 18000 BTU = 5276 watts cooling (Some brands have 1.2 ton AC too)

Area of 196 Sq. Ft. to 300 Sq. Ft. – 2 ton = 24000 BTU = 7034 watts cooling

Above AC tonnage assumption is considering the normal operating situation and keeping cooling level maintained at a 23°C to 25°C. Following are the key points you must consider before deciding the capacity requirements.

  1. Room on the top floor, direct sunlight hits on one wall and roof or ceiling.
  2. Room on the top floor and direct sunlight hit on more than 1 wall.
  3. Room at the top floor.
  4. Room not on the top floor, two walls or more receive direct sunlight.
  5. More number of glass windows or glass walls.
  6. Locality of the AC installation. Eg. Cities where ambient temperatures go to 45°C to 48°C. Eg. Bikaner.

Above factors determine additional load on AC for it to cool the room. Depending upon the heat exposure in above cases, additional cooling capacity of 10 to 15% may be needed.

In order to assist you to get the right calculation, use any of the following tonnage calculators provided by AC manufactures.

  1. https://carriermideaindia.com/tonnage-calculator.aspx
  2. https://www.myvoltas.com/energy-saving-calculator
  3. https://www.generalindia.com/index.php/find-my-ac
  4. https://www.bluestarindia.com/roomacs/tonnage-calculator

Considering all above factors; let us summarize key points to select the AC

  1. When Regular AC is opted, have the near exact capacity based on your room size and load factors. Use above listed tonnage calculators. This is because in case of over capacity of a regular AC, it will waste energy as these ACs by principle cannot vary the compressor capacity. If under capacity, AC will be always running.
  2. If you are opting for inverter AC, over capacity will not have any impact as the AC compressor will work at higher capacity than its rating initially to rapidly cool the room and then lower the power consumption to just maintain the cooling in the room.
  3. When you are going to have an AC in a big room (Eg. 400 Sq. Ft.) and want to just have a single 2-ton AC to just maintain the temperature, then better go for Regular or fixed speed AC. This is because if you go for Inverter AC, ideally it will be running like a Regular AC as to maintain the cooling it will need to continuously run. Also note that inverter AC is typically designed to run 15 to 20% more than rated capacity to rapidly cooling the room. So, it may run consuming high power continuously based on the set temperature. In summary, you will not get any benefit of paying extra for buying the Inverter AC.
  4. Go for 5-Star rated AC. The electrical appliances are rated on a scale of 1-5 depending on their energy efficiency (ISEER) and are indicated by stars for easy understanding. The higher the number of stars, the better is that product’s energy efficiency. Indian Seasonal Energy Efficiency Ratio (ISEER) is the ratio of the total annual amount of heat that the equipment can remove from the indoor air when operated for cooling in active mode to the total annual amount of energy consumed by the equipment during the same period. Details shared in upcoming paragraph.
  5. Do not compromise the cooling capacity while selecting a higher star-rated air conditioner.

AC Buying Checklist – Essential check points to buy the AC

SL

Key Parameter to check for selected Tonnage

Better to go for

When comparing to other product

01

Star Rating for energy saving

5 Star

Highest is better, but costlier. Star rating is directly proportional to Energy Efficiency Ratio (EER). It increases EER need in around 2 years)

02

Indoor Operating Noise

19 to 45db

Should not exceed 58db. Lowest is the best.

03

Outdoor Operating Noise

Up to 55db

Should not exceed 68db. Lowest is the best.

04

Min-Middle-High Power consumption

Low

Low indicate that min. power needed always. High indicate that max. power it will be using to cool room quickly, typically more than rated power. Eg. Whirlpool 1 ton Inverter AC – 375W-920W-1250W

05

Coil material (indoor & outdoor) – Manufacturers reduce the thickness of the copper to reduce the cost. Thus, weight of unit will reduce.

100% copper

Copper is always better in terms of heat transfer efficiency. Both are subject to corrosion. If you live in coastal area, Copper is better. Copper is durable and repairable at site when corroded & leaked.

06

Weight of the Indoor & Outdoor (Based on the thickness of the metal, the weight increases) An indicator to compare.

More weight

Eg. Whirlpool Copper Inverter 1-ton AC Indoor is 9kg & Outdoor is 31Kg. LG 1-ton Copper INVERTER Indoor have 9Kg and Outdoor is 24Kg.

07

Anti-corrosive coating on condenser coil

Must have

Eg. Blue Fin, Gold Fin etc.

08

Auto Cleaning & Self-Cleaning features

Nice to have

These features are by no means related to air filter cleaning. In every couple of days, air filters should be manually cleaned depending on usage. Refer write up given below for additional clarity.

09

Ability to cool at extreme temperature of 50+ °C

Based on your location

Check if the ambient temperature of your location plus 5°C NOT exceed the specified maximum temp capability that AC can handle. Refer to narration given below for this feature’s importance.

10

Stabilizer free

Whether AC have this feature or not, MUST have an external stabilizer to protect complex inverter AC components. Note that if a bad fluctuation occurs, mostly it will only damage the stabilizer which is better than the costly inverter AC.

11

Multi-dimensional Air flow

 

12

Refrigerant leakage detector

 

13

Right capacity (Over capacity when Inverter AC may not harm much in terms of energy cost, but buying cost will be more)

Must

Never go for over capacity if you plan for Regular AC. Read previous para to know details.

14

Auto- restart

Must

After power cut, resumes automatically. Default with most of ACs.

Auto Cleaning in AC / Self-Cleaning in AC features –

These features are by no means related to air filter cleaning. In every couple of days, air filters should be manually cleaned depending on usage. Cleaning the evaporator coil is the function of this feature. Different types or techniques used in this cleaning process. During the self or auto cleaning operation, some brands run the indoor blower for 10 to 30 minutes to evaporate or blow off the moisture accumulated on the evaporator coil during the operation of AC.

In another technology, the temperature on the coil will be lowered during auto or self-cleaning operation causing the surface of the coil to freeze, which in turn removes the dirt on the coil by means of strong cold expansion during frosting and coil surface defrosting. This process results in the removal of dirt on the coil along with moisture removal. There is no doubt that clean coil will improve AC performance.

AC’s ability to cool at extreme temperature of 50+ °C –

The temperature of the compressor chamber (outdoor) will be about 5° C higher than that of the ambient temperature. When the temperature of the compressor chamber exceeds the set temperature limit of the compressor, the compressor will TRIP.

Therefore, calculate the above temperature situation based on your location to determine, if this feature is MUST for to you. But a good feature to have regardless of location. For example. If your location expects an ambient temperature of 45 to 48 °C during peak summer, then the temperature of the compressor chamber will be around 50 to 53 degrees C. In this situation, if your AC specification says it can cool even at 55 °C, the AC won’t TRIP and function normally.

Power consumed by Stabilizer –

Note that the stabilizer will consume around 2 to 5% of the rated power. A branded stabilizer may offer around 95 to 98% efficiency. Due to this if you do not switch of the stabilizer even if you switched of AC, the power consumption will be around 50 to 120W for a 2.5KVA (2.37KW with 0.95 power factor) stabilizer per hour.

Site inspection checklist (or) AC Installation quality checklist

SL

Site condition

Verify for

01

Check whether the hole provision provided in the wall is in such a way that water can flow smoothly to drain out.

If the drain pipe is routed through the hole, ensure that natural slope is there for water to flow out. Else create new hole on wall to route drain pipe.

02

Position outdoor and indoor in such a way that the distance between them is not exceeding the standard pipe supplied by manufacturer

Generally, 3.5 meter to 4-meter copper pipe is given by manufacturer along with a new AC. If the distance between both units are less, ensure that excess length is kept safe in a bundled condition. This is because there is a minimum length of pipe needed for the cool and hot liquid refrigerant gas to flow.

But if the distance is more

03

Distance between Indoor and Outdoor

The refrigerant flows within the copper tubing between the indoor & outdoor unit at very low temperature. The distance between the outdoor and indoor units should be kept as low as possible to reduce the loss of the cooling effect when the coolant flow between the units.

The maximum distance can be about 15 meters between the indoor and outdoor units while minimum distance equal to the length of the copper pipe supplied by the manufacturer with AC. Typically minimum distance is around 3.5 meters to 4 meters. Note that when length of the pipe is increased, gas recharging may be required. Refer manufacturers installation guide to verify the requirement.

04

Earthing

Although earthing is important for regular ACs, it is very high importance for Inverter ACs. Due to the presence of a high frequency in the outdoor unit’s frequency converter (inverter), proper earthing can prevent electricity charging on the outdoor unit surface as well as prevent electrical shock. You may be exposed to an electrical shock if the outdoor unit is not properly grounded. Note that the complex controller circuit of the Inverter AC can also go bad when earthing is improper. The repair or replacement cost will be high and warranty may not cover the same.

Do not connect ground wires to gas pipes, water pipes, lightning rods or ground wires for telephone wires. This is to mitigate the risk of fire.

05

Insulation for pipes

Ensure that the entire length of copper pipe is covered with spongy insulation material and on top of that the insulation tape is wrapped. The complete thermal insulation will help to avoid loss of cooling when the coolant flow between units.

06

Rubber bushings

Ensure that the rubber bushings and inserted between AC outdoor and the stand where AC will be resting. This will reduce the vibrations. Excessive vibrations will damage copper piping and thus lead to leakage of gas.

07

Vacuum

Professional and experienced AC installer is expected to do this before charging the AC. But when I installed inverter AC, the installer was trying to avoid the step. So, ensure that installer using vacuum machine to vacuum the AC unit so that when gas is released in the pipeline it will not have moisture and foreign particles resulting in chemical reaction within coolant (liquid gas) impacting the normal functioning of AC. Typically vacuum process will take up to 10 to 15minutes based on the time taken to achieve the desired vacuum rating. Refer AC installation guide.

08

Gas filling process when a leak happens. Normally not required.

In normal AC, I observed that gas filling level is monitored using a clamp meter. Technicians will watch the ampere consumed while they operate the service port to fill gas. When the current level reaches to the standard ampere rating, they stop filling. Another method is explained here.

In case of Inverter AC, I observed that technicians connected the gas cylinder to service port and loaded manufacture specified kilograms of gas. Weight of the gas was monitored using a weighing scale. I observed the filling of R410A gas to Whirlpool 1-ton inverter AC by Authorized technicians.

09

Capacity of AC

Refer the specific paragraph mentioned in the post.  

10

Flow of outdoor fan air

Always face the air flow towards open area and not to within room. If within room is the only option possible, then ensure that

11

Fix Indoor unit with a slight tilt angle towards the drain pipe side

When affixing the steel indoor AC holder bracket to the wall, ensure that the bracket has a slight tilt angle (say <5 degree), so that the split AC indoor unit is also at a slight angle. This will allow the condensed water from the Indoor unit’s collection tray to flow out smoothly.

12

Space needed above the indoor unit

The gap between ceiling and indoor unit should be at least 4 Inches (recommended is 6 inches or more) for smoot air intake. This is important for efficient functioning of the AC.

13

No obstruction behind the outdoor unit’s Air Inlet

Keep at least 1 feet clear gap behind Outdoor’s blower inlet so that air intake will not be blocked. If such cases happen, Outdoor efficiency will be impacted.

14

No obstruction in front of outdoor unit’s Air Outlet

Keep at least 6.5 feet clear gap in front of the Outdoor blower so that hot air will not be returned to outdoor unit after hitting the opposite wall. If such cases happen, Outdoor efficiency will be impacted.

15

Outdoor unit in a constantly exposed location to strong winds

When an outdoor unit is installed in a location that is always exposed to strong winds such as a coast or on a building’s high stories, use a duct or wind shield to secure normal fan operation. Install the outdoor unit in a location where the discharge air is not blocked by strong wind or wall.

Installation Dimension diagram (Courtesy– Sharp AC Manual)
 

Positioning Indoor and Outdoor units and dimensions of it's position

 Key facts to know before price of AC is compared? 

  1. Many manufacturers and sales people will tell the AC capacity as 1 ton and 1.5 ton. Accordingly, the price will be shared. But note that few manufacturers state the AC is 2 ton or 1.5ton. But if you look on the specification, it will say much lower BTU (British Thermal Unit) capacity. Eg. 20500 BTU in stead of 24000 BTU for a 2 ton AC. So ensure that when you are comparing price, BTU spec is verified. Because BTU tells the real capacity of AC.
  2. In case of inverter AC, typically AC will have a rated power. But it can function around 20% more than rated capacity at start for giving rapid cooling. But the rated power will be always less than the maximum power. Eg. Whirlpool 1 ton AC power rating is shown as “375W-920W-1250W” and its corresponding cooling rating is “1820W-3530W-4400W” or “6210W-12044W-15013W”. That means this AC at start will run at 4400W cooling capacity which is 25% more than its rated 1 ton (3530W) cooling capacity.
  3. The AC coming with 4 meters of copper piping. Some brands will not include it into AC cost. Eg. Daikin or O’General. So check what is included before comparing the price.

BEE Star Rating – Current energy efficient ratio

5 star rated appliances will be needing less power in comparison with lower star rated appliances. For example, 5 star rated Branded 1ton Inverter AC consumes 1250W power at start and it is lowered up to 375W when it just need to maintain the cooling while its rated power is 920W. BEE use ISEER (W/W) scale and this AC have 4.7 as its Energy Efficient Ratio (EER) which is above 4.5 as specified by BEE for a 5 star rated appliance.

BEE rating scale changes in every 2 years and the current rating expectation of BEE Standard for Star rating is as given below.

How to Run Your AC efficiently? 

  1. Run it at 25 to 28 degrees Celsius.
  2. Have 5-Star rated ACs.
  3. Keep your Outdoor units in a shade. Outdoor unit directly exposed to sun light will consume around 10% more electricity.
  4. When low room temperature is set, naturally power consumption will go up.
  5. Clean your AC filter regularly as it can help to reduce energy consumption by nearly 10 %.
  6. If you prefer lower temperature, using the AC with a ceiling fan would be always better.

Ideal time to buy AC

  1. Avoid AC buying at summer, if possible.
  2. If you buy at end of the season, you may get at discounts. But you may be missing new features in the next model that is getting launched after the season.

Copper Vs. Aluminium Alloy Coil

Copper Vs. Aluminium Alloy – ACs now come with aluminium alloy condenser coils where the cost is slightly lower but the life / durability is lower. It makes sense not to compromise the cost by insisting on ACs with copper-coil. They have a much longer life and fewer complaints of leakage. Moreover, these coils can be repaired at site whereas Aluminium coils mostly need replacement. However note that Aluminium coils also sturdy but may have less life compared to copper.

Multi-Split AC vs. Regular Split AC for Home – Right one to choose?

Multi-Split AC is efficient and doesn’t need ducting work for home. Also note that it just need space for a single Outdoor. Following are the key points you should consider when deciding to go for centralized AC.  

  1. Multi-Split AC will have single Outdoor unit and multiple indoor units. Single Outdoor unit and indoors will have refrigerant copper piping for flow of refrigerant. As a result, any failure to Outdoor will cause complete outage.
  2. You will need to have costly annual maintenance contract considering the fact that you cannot go for replacement of a unit when continuous issue is occurring.

Gas leakage symptoms or AC low on refrigerant – Symptoms

  1. Room temperature air or very low cold air coming out from indoor.
  2. Long-time taken for cooling
  3. Energy bill goes up. That is when low gas is there, power (ampere) consumption will be more.
  4. Evaporator coil get too cold causing ice to build up on the coil and also on the surrounding areas of AC. When ice is visible as in the below photo from Knoji website.
  5.  Gas leakage symptom on AC
  6.  

    Brand Options

  7.  
  8. Whirlpool – Product Quality & after sales service is ok.
  9. LG & Samsung – Feature rich and good after sales service.
  10. Panasonic – Quality.
  11. Daikin – Quality. But costly.
  12. OGeneral – Quality, But costly.

I assume that this AC Buying Guide given you a good insight and will help you to identify the right product.

Also I recommend you to read the article – TYRE BURST reason& 1 MUST AVOID & 3 EASY ways to CONTROL CAR

[Disclaimer– Through this blog, I share my learning and experience. Every effort is made to avoid errors. It is not possible to rule out chances of error, however. If you try any ideas or tips given this Blog, it is solely on your risk. I won’t be liable, if you suffer any loss or damage. Meanwhile, I am happy to answer any clarification requests posted via the comments section.

If you notice any error or have a constructive feedback, please notify me. You are also welcome to share the general comments. Your feedback will help for continuous improvement of the content. Thank you for your visit to my Blog Home Page.

Thank you for your time to read my post about AC Buying Guide. If your time permit, have a look on to other posts in key categories appearing in my Blog Home Page.

ac buying guide

You may be interested in these short videos.......

Twitter page.....

How useful was this post?

Click on a star to rate it!

Average rating 5 / 5. Vote count: 3

No votes so far! Be the first to rate this post.

Comments 17

  1. cialis says:

    Great article. I’m facing some of these issues as well..

  2. Kaasim says:

    NIce blog.for Aspects to be considered for AC selection & maintaining.

  3. Kaasim says:

    NIce blog for AC Buying Guide.thanx for sharing.

  4. Hi there friends, its wonderful post concerning cultureand completely explained,
    keep it up all the time.

  5. Wonderful goods from you, man. I have understand your stuff previous to and you’re just too wonderful.

    I really like what you have acquired here, certainly like
    what you’re saying and the way in which you say it. You make it enjoyable and you still care for to keep it sensible.
    I can not wait to read far more from you. This is actually a great site.

  6. classifieds says:

    hello!,I love your writing so much! share we keep up a correspondence extra
    approximately your article on AOL? I need an expert in this space to resolve my problem.
    Maybe that is you! Having a look ahead to see you.

  7. fitoru says:

    your article is worth a read. It is inspirational and really comprehensive. Keep up your work. More power

  8. It is definitely an informational article. I want to add that I have been facing issues regarding the frequent noises of my ac for a couple of weeks. I have consulted with the reliable support for fixing up this consequences https://handyman-dubai.com/ac-repair-dubai.Suggest us what to follow out next?

  9. Like!! Thank you for publishing this awesome article.

  10. If some one desires expert view about blogging after that i recommend him/her to pay
    a visit this webpage, Keep up the good work. adreamoftrains best hosting

  11. Thanks a lot for sharing this with all of us you really understand what you are speaking approximately!
    Bookmarked. Please also consult with my website =). We may
    have a hyperlink exchange arrangement among us

  12. I was very happy to discover this web site. I wanted to thank you for ones time for this
    particularly wonderful read!! I definitely appreciated every bit of it and i also have you book marked to check
    out new stuff in your web site. adreamoftrains website hosting
    services

  13. Undeniably imagine that which you said. Your favorite reason appeared to be on the net the easiest factor to take note of.
    I say to you, I certainly get annoyed whilst other people think about
    issues that they just do not realize about.

    You managed to hit the nail upon the highest as well as defined out the entire thing with no need side effect , people
    can take a signal. Will probably be back to get more.
    Thanks

  14. Article writing is also a fun, if you know then you can write otherwise it is complicated to write.

Leave a Reply

Your email address will not be published.

6K views
Share via
Copy link
Powered by Social Snap