Air Con Terms and Jargons Before I start, there are some technical terms or jargons used in air conditioning which u all should know a little beforehand.
BTU = British Thermal Units. This is a unit for cooling capacity. A higher value means higher cooling power. There are 9000btu(10000btu), 12000btu(13000btu), 15000btu(16000btu), 18000btu, 22000btu(20000btu), 24000btu(26000btu) and 30000btu.
* Some people like to use Hp to define the cooling capacity. Nothing wrong with that but try stick to BTU or kW as both use more commonly in Singapore.
Outdoor Unit = the big rectangular stuff u placed on air con ledge or mount on a stainless steel bracket. Some people call it 'compressor' but actually the compressor is part of the outdoor unit.
Indoor Unit or Fan Coil or FCU (fan coil unit) = this 'air con' inside your home.
Compressor = the main component for your air conditioner. It is mounted inside the outdoor unit.
Refrigerant = the working fluid for air con. There are R22 and R410A currently in use for residential. People always tends to say 'Gas'...Dun do that!!! Caused it is not always Gas...it is at times LIQUID..!
Use 'Refrigerant' instead.
Class 1 & Class O = Fire Propagation Test Standards for insulation. In simple terms, the insulation inability to burn.
Grade = Actually it should be Gauge. It is an industrial term to describe thickness of metal. In our case, thickness of the copper pipe. 'Grade 23' means 0.61mm thick.
Insulation = the foam or rubberly 'layer' covering the copper pipe. Its function is to prevent heat gain.
System 2 (or 3 or 4 or 5) = The figure means number of indoor units to 1 outdoor unit. For example, a System 4 will be 4 indoor units to 1 outdoor unit.
9+12+18 ( or any other number combinations ) = Using 9+12+18 as an example, it means a System 3 with one 9000btu indoor Unit, one 12000btu indoor Unit and one 18000btu indoor Unit.
Single Split = this also means System 1. Therefore it will have 1 indoor unit to 1 outdoor unit.
Non Inverter = the conventional air conditioner or 'fixed speed'.
Inverter = the more energy efficient and expensive air conditioner or 'variable speed'.
Manufacturer or Agent = the manufacturers like Daikin, Mitsubishi Electric, Panasonic, etc.
Dealer = the retailer or installer
**Learning this will not impress the salesman but at least u will not look 'blur blur'. **
Which air conditioner to buy?
Ask yourself these questions first
1) Do you really need an air conditioner?
This should be the first question you should be asking yourself. Many new home owners probably feel that since they are renovating their new home, they might as well install the air conditioner together. But do you have a habit or tendency to use the air conditioner? If you are currently very satisfied with just a standing fan, why should you get an air conditioner?
2) Are you willing to pay the additional electrical cost of using the air conditioner?
Some home owners upon noticing the increase in their monthly electrical bills, decide to reduce or even stop using air conditioner all together.
If you have justified your need for an air conditioning system, u may began to select your air conditioner.
1) Which area of your home do you want to be air conditioned?
This will determine the system combination.
For example,
U want to air conditioned 3 bedrooms and the living. You are likely to either get a System 4 or a System 3 + Single Split.
2) Which brand of air conditioner do you prefer?
You can ask your friends and family for recommendation, look for reviews on the internet, read through the catalogue or visit a few retail shops.
3) What kind of features are most important to you?
Do you want the most energy efficient? Or do you prefer it to be the quietest in the market? Or you want your air conditioner to function as an air purifier? Or it must be 'Made in Japan'? Or you want to find an air conditioner design that will match your home deco? Or you just want an air conditioner?
Try to match your selected features to the available. After that, you will have to determine your TOP 3 models.
Now you can go 'shopping' for air conditioners.
1) Visit a few retail shops and listen to the salesperson's sales talk. Tell them that you are considering between these 3 models and request for their advice. You can also seek their advice on the system combination, inverter or non inverter, R410A or R22 and etc. You would probably prefer to keep this first visit to just selection of models.
2) When back home or having a break, determine which model you want. Decide and proceed for the return visit.
3) This time seek clarifications on prices, installation materials, installation procedures, after sales service, warranty and etc.
4) Finally decide which retail shop you are most comfortable with and make your sales confirmation. To be on the safe side, go through the details and have everything written clearly on the sales invoice.
Pointers when surveying retail shops
When searching for retail shops to install your air con, please remember to ask the following
1) Price includes GST?
2) Price includes 2 times installations? First Installation for Piping only and Second Installation for Indoor Units / Outdoor Units. Some installers will install outdoor unit during first installation.
3) If u do need them to go to home to discuss with you and your contractor how the air con trunk will run, will there be additional cost?
( this is known as site survey or site view, it is done after the major hacking and before the first installation )
4) Make sure the retail shop uses BCA trained workers if you need a stainless steel bracket to support the outdoor unit outside your home. Request the installers to show u their certificate before installation.
** Though for those with air con ledge, it is not necessary. **
5) Go for 'Class 1' or 'Class O' PSB certified insulation though I would say it is not that important as the rating does not reflect the quality and insulation properties on the material.
Nevertheless get them to show u the sample. Ensure this will be use thru out the home and not half or part of it only.
Equally important is the thickness ranging from 1/4'', 3/8'', 1/2'' and 3/4'' (the usual thickness for residential) You have to ask them what thickness they are providing for the insulation. Using a thicker insulation also means better insulation properties but bigger trunk and higher cost.
** Insulation should have the brand, dimensions/thickness and 'Class Rating' printed on it.
6) Go for 16mm diameter PVC water drainage pipe.
** I would recommend insulation (1/4'') for the drainage pipe also but as far as I know, most installers do not like to do that caused it is troublesome and will incur higher cost. Unless, u are willingly to pay.
** through out the home and not part of it. The smaller size will be 10/13mm.**
7) U should use the correct copper pipe diameter
( for the gas and liquid copper pipe ) according to the manufacturer's catalogue. Get the salesman to point out for you.
8) Copper pipe should be all brand new. The colour should be very shiny! If it looks dull means it has left lying around for sometime. But if you see that the 'dull' coil still has the 'coil' shaped, it will still acceptable as it means it has not been used before or partially used.
9) Copper pipe comes in coils of about 10m - 20m (usually 15m), depends on manufacturer. U should insist that they use one copper pipe when possible. This is to reduce the number of joints thus the chances of leakage of refrigerant. But you must understand that when the piping length is more than 15 meters, there will be joints.
**Nevertheless, brazing is a 'safe' method of joining copper pipes.
10) Copper pipe should be bended with a Level Type Hand Bender
(bending tool). This will give a smooth radius. It should not never be bend using bare hands.
11) The thickness of the copper pipe has always been an issue with most of the readers. The market goes something like R22 systems 0.56mm (24SWG), R410A systems 0.61mm (23SWG). U have to confirm with the retailer.
** I personally would prefer 0.71mm for R410A system but I do understand that with the ever increasing price of copper worldwide, this upgrade do not come cheap. Nevertheless, check with the manufacturer if you need any advice.
12) Insist that they do an Evacuation of the system (vacuum process) before they 'release' the refrigerant into the system. This is remove all the moisture in the copper piping. This is especially important in air-conditioners using R410A.
** Not doing this will not spoil your compressor immediately but it is one of the factors affecting the life span of compressor.
13) Check the installation warranty and what it covers like transportation and labour...terms and conditions like validity subjected to yearly service contracts etc
14) Check if they are having their own workers or sub contractors.
** There is no way to know but just ask. Or u can ask other shops about this shop. Basically everyone will say they are using their own workers. Nevertheless, it is always advisable to be there personally during the day of the installation.
15) Make sure it is unlimited piping length. As in no additional charges for installation using more than a certain length.
16) Lastly ask what might the case that u might have to pay additional during installation. If salesman, say no more, that get the salesman to make a note saying that there no more additional charges. If yes, get him to write down, what might be the situation u will have to pay additional.
**Remember whatever is promised to u by the salesman should be written down on the sales invoice.**
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