Air conditioning - Any recommendations please??

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yang_nastyman

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Your prior reply says all 4 will turn on without fail, that's why advise you to get a higher rating compressor, so it won't struggle much.

I guess I misunderstood, I assumed that the cooling will suffer if all of them are switched on at the same time only. The case for my family is that the aircons will be switched on about an hour or two after each other, but kept on for the whole night.

What does "higher rating" refer to? I'm quite lost with all the terms here to be frank!

@serverxeon : thanks for the suggestion, I will do!
 

serverxeon

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Higher rating refers to higher cooling capacity. Usually expressed in kW or BTU/hr.
For system 4 you're probably looking at somewhere around the range of 10kW or 34,000 BTU/hr. That's the heat energy per unit time your compressor can remove. So higher rating is more powerful in layman term

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ksrokiller

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all this five ticks is nothing but scams/ the technology is the same just that they cap the horsepower. it is like the older AE86 car at 1.6L can give 150hp while the current 1.6L car can give only 110hp. the AE86 can yield 14km/l if you cap its horsepower to prevent it from going into fuel guzzer mode.

basically u paid more for capping your aircon real power.

now with capping of the power it means ur air con is not able to support 3 FCU at max capacity as before. it also means u have to pay more to get a higher capacity compressor for something which is not needed if the power is not capped. so basically the benefits goes to the manu and i see no sense to paying more for less power

because of NEA set higher requirement for the ticks?
 
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tanjhj

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That's why I go for the LG's 3 tick A4UQ30GFA0 compressor. It's much cheaper than the japanese brand of similar class rating.
Rated 40K, BTU max.. Comfortably able to support 3 system, with 4 still got some margin..

Yup i am surprised LG giving a system 4 compressor for a system 3. the extra power will be helpful if needed. A4UQ30GFA0 is 3 ticks

I am trying to get this same system but upgrade to A4UQ30GFA1 (4 ticks). I am willing to trade some power for some saving capacity yet will not strain the compressor lifespan.

A4UQ30GFA0 (5 ticks) is too expensive upgrade with abit too much power cut. Yup i am supporting 4 ticks. 5 ticks compressor giving alot of problems as what a installer told me. he said the 5 ticks has more RMA even for ME system.
 
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tanjhj

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because of NEA set higher requirement for the ticks?

well still a scam to me. paying same thing but much more expensive for a device that cap the real power of the compressor is silly to me. i wonder NEA ruling is for the ppl or for the companyies. just like DBSS which is to help the mid range construction companies to squeeze money from the ppl who wanted to upgrade their flats.
 

tanjhj

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Latest utilities bill, really save a lot after getting a 4 ticks new air-conditioning.


Slant your head...
iKHvoZcl.jpg


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there is no real improvement in technology.

what was saved will come back as repair as the compressor has to work much harder to get the temperature u want. it is like a company downsizing and cut staffs so the remaining 3 staffs have to do 5 staffs' work.

if the aircon life span was reduced from normal 10 to 5 or 7, u can count how much money you would have spend on repair and replacement. so the saving you have will be gone or in fact worsen by it. Anyway, it is like politics and current singapore workforce scene adn FT situations. what we thought is savings will turned to bite you

however 4 ticks u get is a balance of the problematic 5 ticks and real power of 3 ticks. which is what i am aiming for.
 

tanjhj

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I guess I misunderstood, I assumed that the cooling will suffer if all of them are switched on at the same time only. The case for my family is that the aircons will be switched on about an hour or two after each other, but kept on for the whole night.

What does "higher rating" refer to? I'm quite lost with all the terms here to be frank!

@serverxeon : thanks for the suggestion, I will do!

i have ME system 3. at night when all air con are on at the same time, i noticed the power drop and the FCU is not able to do the same as before, it have to work harder to get the same power. the compressor also get noiser and strained. i doubt the aircon can last as long as my previous aircon system 3 of 10+ years.

Hence, i am getting the LG system 3 (4ticks) it has enough power to ensure 3 aircons can be on at same time without forcing it to work at strain. i saw that alot of aircon now is giving inferior power compressor (less power compressor than before nea revamp) in order to get 4-5 ticks.

I was thinking to get daikin sys 3 till i saw some sellers was using 5kw compressor (4 ticks) for a 3 fcu 9kbtu (2.5 x 3) = 7.5kw. it is clearly shown the system 3 fcu will not be able to work and cool well when 3 fcu are on at same time. some big air con sellers are even trying to con ppl to get 12k fcu upgrade when clearly the compressor cannot provide the power needed (12k fcu need 3.5kw). too bad many ppl will be conned becoz they didnt check and study. their real system 3 compressor which is 7.1 kw (3 ticks) is still barely making it.

Of coz the FCU will not be needed to work at its full (2.5kw) it will idle between 1.6-2.5kw for a 9kbtu fcu and 2-3.5kw for a 12k btu FCU. however most air con will work at the middle of the range of power needed. etc, a 9k btu will be working at ard 2.1kw so for 3 fcu, it will be 3x2.1kw. = 6-6.3kw. Clearly the 5kw compressor is not able to support 3 fcu.

even it is working, the poor compressor will be spinning at its fastest speed to try cope with the demand. That will explain why there was a spike in compressor noise for 4-5 ticks system
 
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tanjhj

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lets do some study of LG inverter compressor for system 3. LG

Model ticks Max Power Annual electricity bill

A4UQ26GFA2 5 6.47kw $681 (ok not really enuff power for 3 fcu)
A4UQ26GFA1 4 7.18kw $818 (ok barely enuff power for 3 fcu)
A4UQ30GFA0 3 9.02kw $1077 (overkill, but suitable for those who wants 12kbtu upgrade or a 18kbtu for the hall)

lets do some study of LG inverter compressor for system 3. Daikin

3MKS71FSG 3 6.89kw $951 (barely enuff power)
3MWKS80LV1 3 7.41kw $982 (pls note this is sys 4 compressor)
3MKS50FSG 4 4.83KW $601 (not enuff even for 2 fcu:s11:)

LG is able to give the extra juice because it is using system 4 compressor for a system 3 and hence it create savings in money and power it need. feel free to check other brands.

Any way it seems new compressors models are being released by various brands. that explain the "discount and offer" given recently by various brands. they are clearing problematic models ?

https://e-services.nea.gov.sg/els/pages/search/publicsearchproduct.aspx?param=goods&type=p
 
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i_dun_understand

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i was given a quote below

Standard piping materials:
1. 16mm pvc drainage pipe with 1/4 inch thickness armaflex insulation.
2. 23g copper pipe with 1/2 inch thickness armaflex insulation.
3. Keystone/Sigma 3 core 40 & 70 wire.

Optional to upgrade to G22 copper pipe, half inch Armaflex Insulation.

How to tell if the standard package is good enough and the upgrade is a better offer
 

serverxeon

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there is no real improvement in technology.

what was saved will come back as repair as the compressor has to work much harder to get the temperature u want. it is like a company downsizing and cut staffs so the remaining 3 staffs have to do 5 staffs' work.

if the aircon life span was reduced from normal 10 to 5 or 7, u can count how much money you would have spend on repair and replacement. so the saving you have will be gone or in fact worsen by it. Anyway, it is like politics and current singapore workforce scene adn FT situations. what we thought is savings will turned to bite you

however 4 ticks u get is a balance of the problematic 5 ticks and real power of 3 ticks. which is what i am aiming for.
i do not quite agree with your comment though.

what you said is true, albeit in limited situations only. I am inclined to believe that the situation you mentioned will perhaps affect people who tend to stress their compressor more. Perhaps if the household is cooking food, boiling water, or ironing shirt in all four rooms at the same point in time, every day, then perhaps your argument will hold true. Or, if the aircon system is used in a commercial context (perhaps an eatery), then your perspective will very much be correct.

However, in most domestic use, I believe that slight undersizing is acceptable, considering usage patterns and heat rejection demand is not very great.
 

serverxeon

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Just another post to educate everyone,

(From my personal knowledge,)

Real technology improvement in residential aircon systems only fall under 2 major categories.
1) Improvement in COP (Coefficient of Performance). This is an indicator how much electrical energy is required to remove a certain amount of heat energy. The higher the COP, the more energy efficient your compressor is.

Cooling capacity is the amount of heat the compressor can remove in a certain amount of time. It will definitely affect the amount of electrical energy consumed of course. However, do take note that a lower cooling capacity does not necessarily means it's a bad model. It is simply because different models are manufacturer for different target market. Some people do not need great cooling whereas others do. So, it is paramount that you understand your usage pattern when choosing an aircon system, and do not fall for 'lower is lousier' assumption.

That being said, I am absolutely in disagreement with NEA for using electricity consumption as a gauge for benchmarking. NEA's benchmark factors COP and cooling capacity together, giving an idea of the annual electrical cost. Following that, NEA then attaches a 'tick' rating based on the electrical bill in comparison with similar models in that category. However, this method of calculation disadvantages the more powerful models and gives credit to weaker models simply because weaker models use less electrical energy. If I could decide for NEA, I'd instead look at the COP to decide how much 'bang for buck' I will be getting from the compressor.

2) The second improvement is minor, and related to extra features. Ioninsing technology, air purifier, mobile/wlan control, 2 dimensional blower swing, etc. These, I do not need to explain much. I guess you guys can understand this part easily.

I hope I have helped cleared up some doubts and given you a new perspective in aircon choosing!
 

tanjhj

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i do not quite agree with your comment though.

what you said is true, albeit in limited situations only. I am inclined to believe that the situation you mentioned will perhaps affect people who tend to stress their compressor more. Perhaps if the household is cooking food, boiling water, or ironing shirt in all four rooms at the same point in time, every day, then perhaps your argument will hold true. Or, if the aircon system is used in a commercial context (perhaps an eatery), then your perspective will very much be correct.

However, in most domestic use, I believe that slight undersizing is acceptable, considering usage patterns and heat rejection demand is not very great.

Nope. If your aircon need to be all on at same time etc night time, u can see the diff n the lack of power if u used a underpowered compressor. Just work the maths. If ur compressor has to support three 9kbtu fcu, u better get compressor that has 6+ kw or more. Even then ur compressor will be working at max capacity and shorten its life n increase repair cost.
 

yang_nastyman

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So I've actually looked around, and it seems like I might have to fork out quite a bit more if I am looking for compressor units with larger BTU.

I was recommended this by my aircon guy, for my HDB EA unit, http://www.coolserve.com.sg/htmdocs...d=2819&prodName='MXY-4A28VA+/+4+X+MSY-GE10VA' any thoughts?

My guy told me that the aircon nowadays don't last as long as the ones in the past, and advised me not to overspend on something that I might have to change 5~ years down the road.
 

serverxeon

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Nope. If your aircon need to be all on at same time etc night time, u can see the diff n the lack of power if u used a underpowered compressor. Just work the maths. If ur compressor has to support three 9kbtu fcu, u better get compressor that has 6+ kw or more. Even then ur compressor will be working at max capacity and shorten its life n increase repair cost.
i think you have some misconception on the working of the aircon system there.

(Assume a sys 4)
9k BTU/hr per fan coil, is the nominal heat rejection rate per FCU.
Usually, only the initial cooling phase will require up to 9k BTU/hr. If you switch on all 4 FCUs at the same time, the initial cooling phase of your FCUs will theoretically be able to reject up to 36k BTU/hr. That will in turn cause the compressor to run close to maximum load to match the rejection of 36k BTU/hr to the environment. In some cases, the compressor is undersized, and hence the FCUs will then not be able to hit 9k BTU/hr of heat removal per unit ~ hence you see a slower rate of cooling when that happens.

Once the room is sufficiently cooled (or has reached the thermostat temperature), the rate of heat rejection is reduced, and the compressor will run at a lower load setting.

In summary, if your usage pattern requires you to switch on all FCUs at the same time, then perhaps only the first 30 minutes of every day will you see your compressor working at full load. Thereafter, the heat rejection rate will surely decrease.

If your compressor is constantly operating at full load throughout the night, even after a few hours of switching it on, then perhaps your room is generating a lot of heat (electronics or heating devices), or you have a leak of cold air to the environment, or the aircon piping might be faulty (leak/choke/losses)
 
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serverxeon

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So I've actually looked around, and it seems like I might have to fork out quite a bit more if I am looking for compressor units with larger BTU.

I was recommended this by my aircon guy, for my HDB EA unit, http://www.coolserve.com.sg/htmdocs...d=2819&prodName='MXY-4A28VA+/+4+X+MSY-GE10VA' any thoughts?

My guy told me that the aircon nowadays don't last as long as the ones in the past, and advised me not to overspend on something that I might have to change 5~ years down the road.
i will recommend u this instead
http://www.coolserve.com.sg/htmdocs/products/products_details.aspx?id=2829

This uses the 4A38VA instead of the 4A28VA.
According to NEA figures, the 38 has 9.01kW while the 28 has 7.5kW
(bear in mind one FCU is about 2.5kW).

However, do consider what are the chances of all 4 FCUs requiring to operate at max load at the same time. If you switch on 3 at one time, and the 4th some time later, then the 28VA will be able to hit your requirements. After all the price diff is $600. See which fits your usage pattern!
 

tanjhj

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The fcu is usually running on 2kw for 9kbtu on idle mood to maintain the temperature hence if 4 fcu is on at same time. The required power will be 8kw. Still not enuff. however if u dun need your 4 aircon to be on. Go ahead with the 7kw to get the savings. I m more warning for those who are likely to get frustrated becoz of lack of power like in my current system 3
 
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Seasalt

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Hi, I posted a new thread about my aircon having rust in the fan coil, but am not sure if it was correct or I should post here.

Actually, it is rather new, less than 6 months old before it had rust. Need t ocheck if anyone else has rust on their inverter unit.

Thanks
 

yang_nastyman

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i will recommend u this instead
http://www.coolserve.com.sg/htmdocs/products/products_details.aspx?id=2829

This uses the 4A38VA instead of the 4A28VA.
According to NEA figures, the 38 has 9.01kW while the 28 has 7.5kW
(bear in mind one FCU is about 2.5kW).

However, do consider what are the chances of all 4 FCUs requiring to operate at max load at the same time. If you switch on 3 at one time, and the 4th some time later, then the 28VA will be able to hit your requirements. After all the price diff is $600. See which fits your usage pattern!

Thank you for your suggestion and all the help.

Thanks to everyone else for their advice as well; I have learnt quite a bit from this air-con decision experience.

I'll feedback this to my parents, as theyre the ones that will make the decision in the end.

Cheers!:)
 

Hottyhot

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Thank you for your suggestion and all the help.

Thanks to everyone else for their advice as well; I have learnt quite a bit from this air-con decision experience.

I'll feedback this to my parents, as theyre the ones that will make the decision in the end.

Cheers!:)

Coolserve pricing seems higher
 
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