Air conditioning - Any recommendations please??

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Dr.Vijay

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Excellent advice dachee!
Used to do such servicing and installation two decades ago during attachment period. Wish I remembered all that.

I did notice some of the mentioned steps taken, but I couldn't be around all the time to check.

Daikin system 4 successfully installed yesterday. Hope it's installed well.
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dachee

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Thank you Dr Vijay.

Noticed that the Internet search indicates that 410A low pressure line is about 115-120psi, however it was confirmed by Mitsubishi technical support that it should be 120-160 psi.
 
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wilflare

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StarMex has 2, 3, 4 and 5 ticks. Depending on the model.

In my opinion, don't install air conditioner in your living room. Unless you have a special reason for doing so, you will unlikely use it. Like you mentioned earlier: "haven't turned on my Samsung aircon for a good 5++ years now."

So you would likely need a system 3, system 2+1 single split or 3 single splits. All these depend on the power points that you have the approval to install and the price of the units combination as well as technical factors.

Had spoken to some installer about quality workmanship but it all boils down to profit margin.

In my opinion select the price including installation that you are happy with (in most cases, the lowest is better). Before placing order have the seller agree that the installer will do the following which I had posted previously.

In addition to the below, I had also insist that the installer glue the ends of the insulation tubing to each other rather than just taping it. However, I provide the special glue which the installer does not have.

During the installation of your air conditioner equipment by your contractor, it will come to a time when the gas pipes are to be connected to the condenser and the gas in it will be released to operator the system.

At this stage, there are 4 simple checks that you can do to ensure that your system will last you a long time and avoid expensive repairs.

1. Before the installer connects the gas piping to the condenser and FCU, check that he purge the piping IF he had done brazing on that line. Normally, a "good" installer will pump nitrogen into the pipe while he braze the pipe to ensure that the inside surface of the pipe does not for copper oxide that will affect your system. More information can be found here: http://www.rses.org/assets/rses_jour...4_Nitrogen.pdf

However, if you are using new pipes, than there should be no brazing and only flare fitting joints are used unless installer "screwed up"!

2. After the installer connects the gas pipes to the condenser, he is required to vacuum the pipes to remove air and moisture inside it. NOTE that the DURATION of vacuuming is 15 mins or more. Many installer will do it for a very shot period or 5 mins (some don't even do it), specially when you don't time them. Proper vacuuming is important to protect the compressor, other parts as well as for effective cooling and for leak check.

3. After the 15 mins of vacuuming, the installer will have to close the low pressure manifold gauge valve (to make it easier for readers, look for the blue gauge and blue knob on the manifold gauge) and shut off the vacuum pump. AT THIS MOMENT, take a photo of the blue gauge focusing on the gauge pointer reading. Then wait for 1 to 2 mins and take another photo of the same gauge. Compare the position of the gauge pointer. If the position of the pointer has changed, even for a slight amount, is a sight of leaking some where in the piping or the manifold gauge tubing. The installer has to rectify this issue and redo the vacuum all over again. If this is not comply, you cannot confirmed that your system will not leak in the next 3 months time, one year time or even 2 years time when your warranty is over.

4. After the above point 3 is done accordingly, and the system is running, ask the installer to apply some soap and water solution over the service valve at the condenser to confirm that there is not leaking. If soap bubbles start to grow bigger at the valve, it is a sight that some thing there is leaking. The installer needs to rectify this and redo the soap leak test again.

The above are common practices that installers will normally skips from the manufacturer's installation requirements but can be very costly for you in future. Some installer may even argue with you for doing this, so get the understanding and agreement from the dealer that you purchase the system from that you want these steps to be done.

The above are my opinion and hope that they are helpful

thanks dachee! you are really gem in this thread.
we decided to stop using the Samsung aircon because they kept leaking (despite multiple servicing) and the cost of usage (think it wasn't a very energy efficient model)

hopefully, the new aircon unit would be much better. probably would use the 5-star Starmex?
 

dachee

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thanks dachee! you are really gem in this thread.
we decided to stop using the Samsung aircon because they kept leaking (despite multiple servicing) and the cost of usage (think it wasn't a very energy efficient model)

hopefully, the new aircon unit would be much better. probably would use the 5-star Starmex?

Hi,

Air conditioner leaking water has a few definite causes, depending on where the leak is.

Leaking from the FCU can likely be caused due to:

1. Choked drain pipe - this can be caused by dirty FCU as well as slime forming in the pipe. You can use a balloon airblower (pump) or convert your vacuum into a wet vacuum with a 2 litres pet bottle to blow or suck out the slime (clog). Never vacuum water into your dry vacuum.

2. Water condensation on conduit, flooring or ceiling due to poor or deteriorated drain pipe insulation. If the pipes are exposed, replacing the insulation would help. If it is concealed, try to run alternative piping (with proper insulation) rather than to work on the existing pipe.

3. Water condensation on the body or louvers of the FCU as a result of wet air from the toilet or frequently opened door. Proper placement of the FCU is important to avoid such problem.

People normally shower with warm water in the toilet and if this humid air from the toilet is allowed to be in contact with the FCU cool body, water condensation can happened. It is common to see FCU placement just outside toilet door in HDB layout.

4.1 Water leaking from the air conditioner piping due to water condensation can be a result of insufficient refrigerant. OR

4.2 as a result of deteriorated piping insulation. You can change the insulation at a cost of $1.50 to $2 per six foot run. Special glues are available to joint them together or you can get those double sided adhesive insulation.

5. If your FCU freeze up, you are sure to have low in refrigerant. You need to check for leakage before topping up. You can do it yourself if your condenser is located at a safe place to work.

Above are my opinion and hope that they are helpful.
 

exterminazn

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Hi Dr Dachee

Wanna install extra aircon unit in my room

Current setup is 2 units at separate room connected to a single compressor.....

The compressor is in my room.... not sure abt the BTU or model of my compressor.... but if really need to, I can check so that more advice could be given....

Any contractor for recommendation to check the next step to install the extra unit and quote?

Pls pm me....
 

dachee

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Hi Dr Dachee

Wanna install extra aircon unit in my room

Current setup is 2 units at separate room connected to a single compressor.....

The compressor is in my room.... not sure abt the BTU or model of my compressor.... but if really need to, I can check so that more advice could be given....

Any contractor for recommendation to check the next step to install the extra unit and quote?

Pls pm me....


Hi,

Instead of pm you let us communicate openly so that other readers can benefit from the exchange.

Do let me know if I missed understood you.

You currently have 2 FCUs (indoor units) connector to a condenser (outdoor unit). Right?

If so, such arrangement is normally called a system 2.

Normally the condenser ( the outdoor unit that house the compressor and other operating parts) are installed outside the house. Why is your condenser inside your room? Did I get it wrong here?

If you need to install another FCU in another room (ie the 3rd room), than you would need to have another condenser connected to the new FCU, meaning you need a single split (or sometime called system 1), unless your current condenser is a system 3.

To install an addition single split, it will depend whether a new power point can be installed. This will then depend on whether your house is a HDB or private. If it is a HDB, you will have to check with HDB on whether you can have 2 power points.

If it is a private property, you can get an electrician or the air conditioner contractor to install a new power point for you.

If your current air conditioner is a system 3, you can just connect it to a new FCU without the need to buy another condenser but this new FCU must match the current condenser. You need to check with the contractor for a matching FCU.

Hope that I have answer your question.
 

exterminazn

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Hi,

Instead of pm you let us communicate openly so that other readers can benefit from the exchange.

Do let me know if I missed understood you.

You currently have 2 FCUs (indoor units) connector to a condenser (outdoor unit). Right?

If so, such arrangement is normally called a system 2.

Normally the condenser ( the outdoor unit that house the compressor and other operating parts) are installed outside the house. Why is your condenser inside your room? Did I get it wrong here?

If you need to install another FCU in another room (ie the 3rd room), than you would need to have another condenser connected to the new FCU, meaning you need a single split (or sometime called system 1), unless your current condenser is a system 3.

To install an addition single split, it will depend whether a new power point can be installed. This will then depend on whether your house is a HDB or private. If it is a HDB, you will have to check with HDB on whether you can have 2 power points.

If it is a private property, you can get an electrician or the air conditioner contractor to install a new power point for you.

If your current air conditioner is a system 3, you can just connect it to a new FCU without the need to buy another condenser but this new FCU must match the current condenser. You need to check with the contractor for a matching FCU.

Hope that I have answer your question.

Thanks for the post.

Apologize for the confusion, the compressor is installed outside of my room.

Current living in a 4rm HDB flat.

Any reco for contractors to determine which option should I be getting?
 

dachee

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dachee.

May I have your opinion on the following York model. system 3.

http://www.johnsoncontrols.com/en_s...ial/multi-split-grande-high-efficiency-series

YCHMXC009 x3 FCU
YCHMY021 x 1 compressor.

Actually already paid deposit for this model. but still wish to listen to some honest opinion.

Hi,

The FCU features are reasonable but much lesser than the Mitsubishi Electric StarMex models. The FCU noice level is 20 dB which is quite quiet at low speed. StarMex is 19 dB. The condenser is comparable with 4 ticks, inverter and rotary. However for some reason, the 4 ticks given by York has made reference to the year 2014. Don't really know what York mean with this remarks.

If I am not wrong, the specification total capacity is calculated differently from that of Mitsubishi. York only take into consideration the FCU capacity but not the condenser. So for unlimited current property (your house), your 3 FCUs can have 9+9+9, ie 2.4+2.4+2.4 kW giving a total capacity of 7.2 kW (or 24.5k Btu) This is not the capacity that the condenser can support as the MYC021 condenser only has 20.4k Btu. There is no indication as to the distribution of the capacity for each FCU in the specification.

Nevertheless, the 5 ticks StarMex also do not indicate this anymore.

However, the capacity also depends on the setting temperature and other factors like your activity, heating sources, hot air leaking, humidity in the room, etc.

But in reality, your room may not need the 9 k Btu and therefore the 20.4k Btu may be sufficient.

It is therefore good to know the Btu that your room needs.

You may wish to know that the total capacity of 7.2 kW specified by York is based on indoor temperature of 27 degree C DB (dry bulb), 19 degree C WB (wet bulb) and outdoor temperature of 35 degree C DB.

The above are based on technical specification and has no reference to the quality of the product.

The above are my opinion and hope that they are helpful.
 

gold_eagle36

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thanks so much for your detailed explanation.

new hdb rooms pretty small.Taking reference from your previous post seems that I'll be ok.

I think 2 common rooms each maybe 45 to 50m3.

even my mbr I'm guessing it's at the most 55 to 60m3.

plus I'll likely run 2 out of 3 fcu for night as one of the room is for day time use.
 

ryangoh

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Hi,

There are a few things that is good to know.

1. Within the same brand, there are more than one model with system 3 as a result of different condenser capacity as well as the combination of the number of FCUs and their capacities.

2. Within the system 3 of different brands, they have different specifications on the condenser as well as the FCUs as individual factors such as COP, capacity, the fan speed achievable, the noise level.

3. And as a whole system there are the number of energy label ticks, the annual cost and annual kWh.

4. And lastly, the way you wish to use the system and the layout and size of the room as well as your activities and other heat sources.

You may wish to know that the annual cost calculated by NEA is based on an 8hrs operation with 16 hrs of standby at 27 cents /kWh BUT only at about 30% of the full capacity of the system. This limit the room temperature to about 6.5 degree cooler from the outside temperature.
If you see a model with annual energy cost of $620, you would need to triple it, ie $620X3.33 = $2,064/year if you run your system at full capacity.

You may noticed then that the saving from energy is sufficient to off set the cost of the whole system within a year and the half or 2 years.

It is therefore good to look beyond the initial cost.

The above are my opinion and hope that they are helpful.

Dear dachee,

Is dalkin spare part exp than Mitsubishi when comes to repair? Heard salesman saying

Thinking of getting dalkin from below link. 4tick at this price $2k plus look good deal.

http://www.lazada.sg/daikin-inverter-system-3-aircon-3-hdb-promo-ftks25dvm-3-3mks50fsg-free-installation-2567668.html
 

ryangoh

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Hi all

Can I know what is the main difference between sys 3 with or without inverter?
 

dachee

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Hi all

Can I know what is the main difference between sys 3 with or without inverter?

Hi,

Most air conditioners nowadays are with inverter. It does not matter whether it is system 3, 2 or 4. Even single split comes with inverter.

Inverter air conditioner allows the compressor motor to run at different speed rather than just one speed as with non-inverter compressor motor. As such, it need not have to turn off and on when the set temperature is reach like the non-inverter system. Instead, it adjust its speed to different heat load in the room.

Below are some advantages of using inverter:

1. Energy Savings is one of the most important factors to consider when buying an equipment. In the long run, the benefit outweighs the initial cost. The inverter technology uses less energy compared to the traditional system.

ON/OFF type of compressor has large starting current, sometimes 6 times more than the running current. This causes flicker to lights and the energy consumed is greater. Typically, there is a 20% to 30% savings in power consumption.

2. Comfort to the users is another advantage of this system. During start-up, the compressor can run full speed to provide quick cooling to the room. After the desired room temperature has been achieved, the speed of the compressor is regulated using the variable frequency drive based on the required cooling load of the room.

The fluctuation of temperature is minimum compared to the ON/OFF type of compressor. This provides a comfortable environment for the occupants at all times.

3. Quiet Operation is another feature that inverter technology offers. The outdoor unit which contains the inverter compressor is much more quieter compared to the non-inverter compressor. Hence, you do not have to worry about noise when you sleep.

Of course, there are disadvantages.

The above are my opinion, hope that they are helpful.
 

dachee

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Dear dachee,

Is dalkin spare part exp than Mitsubishi when comes to repair? Heard salesman saying

Thinking of getting dalkin from below link. 4tick at this price $2k plus look good deal.

http://www.lazada.sg/daikin-inverte...vm-3-3mks50fsg-free-installation-2567668.html

Hi,

Not really cheap at $2.5k+.

Beware of the following:
AIR-CON REPLACEMENT = Use Back All Old/Existing Air-Con Piping / Old Wire Cable / Old insulation / Old Copper Pipe / Old Trunking. (New Installation Package Available)
Free Install New Air-Con / Free Delivery / Free Dismantle & Dispose Old Air-Con System/ Free Air-Con
Stainless Steel Bracket and power point are not included.

All the above can have great consequences and more cost added.
 

ryangoh

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Hi,

Not really cheap at $2.5k+.

Beware of the following:
AIR-CON REPLACEMENT = Use Back All Old/Existing Air-Con Piping / Old Wire Cable / Old insulation / Old Copper Pipe / Old Trunking. (New Installation Package Available)
Free Install New Air-Con / Free Delivery / Free Dismantle & Dispose Old Air-Con System/ Free Air-Con
Stainless Steel Bracket and power point are not included.

All the above can have great consequences and more cost added.

Now I know what air con replacement actually means. Thanks for explanations...
 

ryangoh

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Hi,

Most air conditioners nowadays are with inverter. It does not matter whether it is system 3, 2 or 4. Even single split comes with inverter.

Inverter air conditioner allows the compressor motor to run at different speed rather than just one speed as with non-inverter compressor motor. As such, it need not have to turn off and on when the set temperature is reach like the non-inverter system. Instead, it adjust its speed to different heat load in the room.

Below are some advantages of using inverter:

1. Energy Savings is one of the most important factors to consider when buying an equipment. In the long run, the benefit outweighs the initial cost. The inverter technology uses less energy compared to the traditional system.

ON/OFF type of compressor has large starting current, sometimes 6 times more than the running current. This causes flicker to lights and the energy consumed is greater. Typically, there is a 20% to 30% savings in power consumption.

2. Comfort to the users is another advantage of this system. During start-up, the compressor can run full speed to provide quick cooling to the room. After the desired room temperature has been achieved, the speed of the compressor is regulated using the variable frequency drive based on the required cooling load of the room.

The fluctuation of temperature is minimum compared to the ON/OFF type of compressor. This provides a comfortable environment for the occupants at all times.

3. Quiet Operation is another feature that inverter technology offers. The outdoor unit which contains the inverter compressor is much more quieter compared to the non-inverter compressor. Hence, you do not have to worry about noise when you sleep.

Of course, there are disadvantages.

The above are my opinion, hope that they are helpful.

Wow thanks for sharing. Very useful yet easy to understand.
 
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