Whenever I have the chance to conversate with people from other countries, they usually mention how they love a season such as spring or winter. Then I make this small joke about only having one season in the Philippines. HOT. Especially since summer is fast approaching, having an air conditioner is simply becoming a need for most in this scorching heat. So we truly hope this guide will be simple yet comprehensive enough in providing you the adequate information when purchasing your next air conditioner. Now let’s break it down!
Table of Contents
Size of Room
Before even heading to the appliance store to drool over some air conditioners, start by determining the size of the space you need to cool. Because the larger the area, the more horsepower (HP) you’ll need. The appropriate power of your air conditioner is important not only in terms of how adequately cooled your room will be but also in how much electricity it consumes.
If your air conditioner is too weak for the size of your room then it won’t be cooled adequately and you’ll get some nasty t-shirt stains from all the sweat. Whereas if it is also too strong and has more than enough horsepower, it will just end up wasting energy by overcooling the room which leads to the aircon turning on and off more frequently to maintain your target temperature. In the end, you want to make sure that you get the right size to ensure that you aren’t spending as much on your electricity bill while still having your room properly cooled.
Image Credit: Wikihow.com
Usually, you can have a professional do the job of surveying the site to fit the right aircon. Or rather you could do it yourself by grabbing yourself a handy tape measure. All we need is some basic geometry to determine the area in square meters. For most rooms that are either box or rectangular shaped, multiply the length (L) by its width (W), or (L x W) to get the area.
But there are certainly more things to consider when measuring your room. Is there a window? How tall are your ceilings? In addition, if the room is heavily shaded, you can reduce the needed cooling capacity by 10%. If the room is extra sunny, it is recommended to increase your needed cooling capacity by 10%. If more than two people stay in a single room, it would be best to note around an extra 633 kJ/hr per person. If the unit is a kitchen, you should note increasing your needed cooling capacity by about 4,220 kJ/hr.
Cooling Capacity
The cooling capacity of an air conditioner is usually measured in kilojoules per hour (kJ/hr) here in the Philippines but is measured normally as well in British Thermal Units (BTU) as well. The cooling capacity of an air conditioner simply describes how powerful the unit is or how much heat per hour an air conditioner can remove in the room.
To calculate the estimated cooling capacity, you would need the size of the room multiplied by 500 or (Sq.meter x 500). Below you’ll see a simple guide to know how much horsepower and cooling capacity are adequate enough for how big each of your rooms is. The numbers found below are based on data by Meralco and the Department of Energy.
| Room Size | Horsepower | Cooling Capacity |
|---|---|---|
| 6 - 11 m² | 0.5 hp | 3,000 - 5,500 kJ/hr |
| 12 - 17 m² | 0.75 hp | 7,385 - 8,440 kJ/hr |
| 18 - 22 m² | 1 hp | 9,495 - 10,550 kJ/hr |
| 23 - 27 m² | 1.5 hp | 12,660 - 13,290 kJ/hr |
| 28 - 40 m² | 2 hp | 18,990 - 20,045 kJ/hr |
| 41 - 54 m² | 2.5 hp | 25,320 - 26,580 kJ/hr |
Energy Efficiency Ratio (EER)
Have you ever noticed this yellow card attached on the front of new aircons for sale? These show the energy efficiency of the aircon. It is attached due to the fact that air conditioners are no doubt, expensive to run and take a lot of energy. So energy efficiency is one of the things you’d want to consider when getting an aircon.
The best way to check the efficiency of an air conditioner is to check the paper for its EER or its Energy Efficiency Ratio. The basic thing to know is that a higher EER would mean that the air conditioning unit is more efficient and would hence have lower costs when running it.
Image Credit: Department of Energy
Electricity Cost
If you really want to get into the nitty-gritty of choosing an air conditioner. Then you may actually calculate an estimate on how much it would cost to operate. You may also find this formula on the yellow paper found on the air conditioner.
- Power Consumption (kWh) x Usage (Hours) x Power Rate (Pesos/kWh)
For example, if the estimated electricity rate would be P9.6/kWh, and let’s say you leave the aircon on average about 10 hours a day both day and night. If an air conditioner’s power consumption is 930W, that would mean we would need to convert it to kilowatts as the power rate is in kilowatt per hour. That would give us 0.93 kWh. So you could expect that for a days use of our example air conditioner would be:
- 0.93 kWh x 10 hours x 9.6 pesos / kWh = P89.28 per day
- P89.28 x 30 days = P2,678.4 per month
- P2,678.4 x 12 months = P32,140.8 per year
Just note that this is an estimate and that other factors can play into it such as days where you leave it on for longer or shorter or where your air conditioner may be placed, how many people there are, or if you choose a non-inverter or an inverter air conditioner.
Inverter or Non-Inverter?
You may notice that some aircons are either inverter types or non-inverter types. The bottom line is if you plan on running your air conditioner for a long amount of time such as in your bedroom when you sleep or where you mostly work throughout the day, then getting an inverter aircon model will help you save money over time. However, if you plan on using your AC for short periods of time like around an hour two at a time, then getting a non-inverter would suffice and be just as efficient as one with an inverter in this case but note that non-inverter aircons are generally more affordable.
But what is an inverter? Inverters are devices that work with your aircon’s compressor to control incoming electrical current. In essence, they can speed up or slow down depending on the room temperature. Once the room is cool enough, an inverter aircon does not completely turn off but will have the compressor run at lower speeds, consuming less energy than full speed. If further cooling is required, then the inverter speeds up again to cool the room.
Non-inverters, on the other hand, use fixed-speed compressors that simply turn off when the room’s desired temperature is reached and turns back on again as the room temperature rises. This simply on and off by non-inverter aircon can take a lot of electricity, especially when done for long periods of time. Below is a simple graphic illustration by Metropolitan Air Conditioning showing how both an inverter and non-inverter air conditioner would work.
Type of Aircon (Split or Window)
Now that you have an idea of how powerful your aircon needs to be to adequately cool your room. It’s time to choose what type of aircon you need. There are basically 2 types of aircons we would normally see in most rooms. That is the Window Type or the Split-Type.
Window Type Air Conditioners
These are the types of aircons you may be most familiar with. They can fit usually into most windows and are pretty easy to install with it requiring little to no professional help.
These are usually used in rooms that aren’t as large as they usually come in between 0.5 at the very least and up to 2.5 horsepower at most.
Split-Type Air Conditioners
As the name would imply, split-type aircons are divided into two components. The first is the indoor unit that we normally see in our rooms up above. The second is the outdoor unit that houses the condenser and compressor.
Split-type aircons tend to be more efficient in covering a wide area and are generally less noisy due to the compressor being located outside. However, they can be generally more expensive and would require the help of a professional installer to set up.
Other Types of Air Conditioners
There are a couple of other types of air conditioners you may want to consider. The first is a hand portable aircon. A portable aircon works pretty much similar to a window unit but the downside is that both components are found indoors instead of having the condenser and compressor outdoors. This would entail that heat would be emitted inside which would then be picked up by the thermostat of your AC, which would in turn make it work harder and less efficient. But if you have no choice but to have a portable aircon on hand then just know that although portable, it comes at the cost of floor space, being less efficient, noisy, and having the hassle of emptying its water tank every now and then.
The other type is usually reserved for larger rooms and that is the standing unit. Just note that these are actually split-type units with an outdoor component. Standing aircons usually start at around 4hp and are rather used for offices or living rooms where it would save space by having a standing unit instead of multiple split units. Just note that these tend to be more costly to buy, install, and maintain.
Final Thoughts
Choosing the right air conditioner for your home can be quite a challenge with all things considered. So it’s up to you to select which fits best for your room! We truly hope this guide has helped you evaluate what to look for in an air conditioner. So get out there and start checking which air conditioner suits your needs best! Let us also know if there are any other tips you know when selecting an air conditioner that could help others in choosing the right one!
Sources: Meralco, Department of Energy, 101 Appliance, Matts Cradle
