Aircon BTU Guide Introduction
An Aircon BTU Guide is a big help to people who are installing aircons in their new homes. If this is your first time buying Aircon, you will be bombarded with foreign terms such as: 9000 BTU + 18000 BTU. BTU stands for british thermal unit, which is the amount of energy needed to raise/cool one pound of water by one degree Fahrenheit. If you turn the aircon inside the room on and didn’t close the door, chances are your house will not get cooled. Why? This is because you have insufficient BTU to cool the whole house due to the increase in space. Hence in short, the bigger the room, the more BTU you need to cool the area. This article is an Aircon BTU Guide for your reference if you’re looking for help before aircon installation.
What are some of the other factors that affect BTU?
As you have learned in science class back in primary school, heat travels from hot to cold places. Hence, a room close to external sources of heat requires the aircon to work even harder. This means you will require a higher BTU for a crowded room. Or, if it is a commercial property with a lot of printing equipment, the BTU level needed is much higher as well. Other than heat sources from the inside, you will have to consider the potential heat source from outside. Which means if you have a window facing the east or west direction, an air conditioner of higher BTU may be necessary to cool the room. This is because the sunlight will heat up the room during certain times of the day, depending on where your window is facing. Even if you install curtains, the sun radiates heat onto the walls of your home, causing your room to be stuffy and hot. This is especially so for units on the highest level, it will be hotter than usual as the sun rays are in closer proximity to your room.
Is excess BTU a good thing then?
As mentioned earlier, your aircon in the room would not cool the whole house because it doesn’t have enough BTU. However, can your aircon in the living room be used to cool your room then? Answer is – YES it can. But is it good for you? It definitely isn’t. BTU that is higher than required will cause it to cool too quickly, cycle off, then cycle back on in order to maintain the lower temperature. This is known as short cycling. This can cause the aircon compressor to overwork quickly, resulting and more wear and tear. It will definitely increase your electrical bills as well, even if you are using an inverter aircon.
Will my room be cooled if my Aircon BTU is insufficient?
You will still feel a sense of cool breeze in your room. And depending on the time of the day, it could still be cold. However, on very hot days, this will not hold true. In addition, it’s not just a matter of whether you room will be cooled. If your Aircon BTU is insufficient, it will cause the compressor to keep running, as the thermistor will indicate that it’s not sufficiently cooled yet. This will cause huge wastages in your electricity consumption and cause insanely high electricity bills. Hence, it will be better if you err on the side of caution and choose higher BTU.
How do I calculate the aircon BTU that I need then?
First and foremost for HDB units, this is pretty straightforward. You can simply follow these pointers here for a rough estimation on the amount of BTU required:
- Normal Room – 6500 BTU
- Master Bedroom – 9000 BTU
- Living Room
- 2 / 3 Room Flat – 12000 BTU
- 4 Room Flat – 18000 BTU
- 5 Room Flat – 21000 BTU (Only Daikin) or 24000 BTU
- However, there are areas in Singapore with bigger room or living room. For example, some of the 4-Room Flat in Tampines have large living rooms.
Hence, to be safe, you can also calculate the amount of BTU required on your own, taking into consideration your floor plan. Outlined below are the 2 methods you can use for the calculation:
Take the area of the room (in sq ft) that you wish to install the aircon at, and simply multiply by around 50-60. You will get the BTU you need. Size of an average HDB room is 130 square feet. There’s no definite thumb of rule to follow, saying which number you should multiply by, but the range given is 50-60. So to gauge, you can see if you have encounter these scenarios:
- Multiple Electrical Appliances within the room
- Internal/External Heat Sources
- Direction of the Sun, dependent on where your room is facing towards
- Ceiling Height (High ceiling will require more BTU)
If you have encountered all scenarios, then you should multiply by 60. Otherwise, you can just multiply by 50 if you didn’t encounter any of these scenarios.
Take the area of the room (in sq metres) that you wish to install the aircon at, and simply divide by 5. You will get the the cooling capacity in kilowatt (KW). Following which, to convert kilowatt into BTU required, take that result and multiply it by 3412.
If you have been measuring your house based on square meter, you can simply take that area and divide by 5. However, the cooling capacity that you will get is in terms of KILOWATT (KW). To convert kilowatt into BTU, multiply the result by 3412.
The method is referenced from energy efficient Singapore website :
However, as described in earlier paragraphs, you will have to take note of the internal and external heat source generated from your room. Other than the external heat sources, you will also have to consider the height of the room. Furthermore, do note that the calculations we have provided only helps to calculate your required BTU base on square feet. So for warehouse or places with high ceiling, you will have to get higher BTU too. We would personally advise you to contact us at +65 9177 5500 to book a free site visit with us so we can assist you in better diagnose your aircon needs. Besides advising you on the BTU that is required, we will recommend specific brands and systems for you too. Alternatively, you can click on the button below and it will direct you to our WhatsApp directly.