Singapore Expats Forum

Aircon servicing every 3 months - Tenant Pay?

Discuss about the latest news & interesting topics, real life experience or other out of topic discussions with locals & expatriates in Singapore.

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Tue, 12 Apr 2016 8:57 pm

Brah wrote:Dunno, ours always seems to peter out around the 3-month mark.

We use them regularly but never all day.

I wonder if they really require less cleaning as the service, and more Freon recharging instead.

Here's a question - do aircons use more electricity than ceiling fans? I would think so and that it depends on the respective units and usage (aircon temp and fan speed, dehumidifier, fan speed and size, etc.).

If the aircon is all ok (all the pipes and connectors intact), it should need no topping up of the gas at all. This is just a fridge and nobody tops up the fridge.

For the question: it's incomparable or very difficult to compare. The fans surely use less electricity (it is related to moving around the volumes of air) but the end effect depends on your subjective feeling how moisture/water on your skin gets evaporated.
Aircons lower the ambient temperature and this takes a lot of electricity. Aircon is like a heater but even worse. You have compressed gas, this gas when expanded takes the heat (energy) from the environment cooling the environment down. This energy has to be later put back to the gas by compressing it again.

User avatar
ecureilx
Immortal
Immortal
Posts: 9790
Joined: Fri, 20 Aug 2010

Re: Aircon servicing every 3 months - Tenant Pay?

Postby ecureilx » Tue, 12 Apr 2016 9:16 pm

x9200 wrote:Why BS. As an engineer I would be surprise if such appliances have no protection against low gas level that would simply shut down the compressor pump. Same goes for overheating. The worst what I could expect is the unit to shut down or not willing to turn on with some LED blinking. For the allegedly dirty compressor, the worst I could expect with the level of dirt I can see on the fins is lower cooling efficiency. Can somebody with more hands-on experience confirm if my reasoning is correct?


Ok, unless technology changed, low gas or no gas used to lead to compressor seizing up, in older Split Aircons. That's what I learnt as an apprentice in air con company. I am sure since then technology changed to detected low gas etc, but I also doubt cheaper aircons have such safety feature. Yes, the same compressor that's generally guaranteed for 5 year ;)

To be honest, the gas issue is one problem you can always avoid with a Window / Casement unit (no tubes / pipes / joints - no leaks but bear with higher noise in return), or engage a different contractor who can use a gas leak detector at the joints to really check for leaks and double seal them. If the gas leaks constantly, the contractor lacks proper gas detection equipment.

Brah wrote:Dunno, ours always seems to peter out around the 3-month mark.

We use them regularly but never all day.

I wonder if they really require less cleaning as the service, and more Freon recharging instead.

Here's a question - do aircons use more electricity than ceiling fans? I would think so and that it depends on the respective units and usage (aircon temp and fan speed, dehumidifier, fan speed and size, etc.).


For my 2 cents, if you use a good indoor 3M Filter in the evoporator, and your servicing fellow did a good job, it should last 12 months before service. Or 6 months plus, if the condensor is anchored properly.

I have my friend doing Aircon and such work in Dubai and around there and they were in fact confused about the quarterly serving in Singapore. And don't tell me Singapore is more hotter than Middle East.

As for power consumption, it's the compressor that consumes a lot of power, when it starts up, and that definitely will beat Fan Current consumption.

A possible saving measure - if you plan to stay in your place for long: Get a Sanyo Casement Aircon. It can be self installed in the window rails. And see if that serves the purposes. That's as long as the land lord allows you to skip the 3 month maintenance of the existing :) Just remove the filters and wash them and likewise you can vacuum off the back too on your own. And it's the quitest aircon of the casements ;)

My 2 cents would be, if the landlords replace aircons older than 3 or 4 years with new ones, the newer ones would be quiter, save more energy and need lesser maintenance - and will be healthy as newer ones even do anti bacterial cleaning.
Last edited by ecureilx on Tue, 12 Apr 2016 9:20 pm, edited 1 time in total.

User avatar
ecureilx
Immortal
Immortal
Posts: 9790
Joined: Fri, 20 Aug 2010

Re: Aircon servicing every 3 months - Tenant Pay?

Postby ecureilx » Tue, 12 Apr 2016 9:19 pm

x9200 wrote:If the aircon is all ok (all the pipes and connectors intact), it should need no topping up of the gas at all. This is just a fridge and nobody tops up the fridge.


That's where you are bit wrong. In Split Aircons, the joints are connected by flanges and tubes that may develop kinks, come lose, plus the Compressor, if not anchored properly, can vibrate and make the joints open up, a problem you don't have in Fridge, or Window Aircons, or Casement Aircons. In the latter, it's all sealed and welded in place - not much room for leaks.

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Tue, 12 Apr 2016 9:44 pm

ecureilx wrote:
x9200 wrote:If the aircon is all ok (all the pipes and connectors intact), it should need no topping up of the gas at all. This is just a fridge and nobody tops up the fridge.


That's where you are bit wrong. In Split Aircons, the joints are connected by flanges and tubes that may develop kinks, come lose, plus the Compressor, if not anchored properly, can vibrate and make the joints open up, a problem you don't have in Fridge, or Window Aircons, or Casement Aircons. In the latter, it's all sealed and welded in place - not much room for leaks.

There are also flanges and tubes and a vibrating motor in a standard fridge. If something is done right it should not leak. My bet is, most leaks occur as the results of lousy repair / maintenance. In our first apartment where we lived or 7y, none of the units has ever been in need for the top up. In the current apartment there was no problems with it for 2 years and then I engaged the current company and almost every visit they "discover" something new. What is interesting, they wanted me to pay $40 to top up a single compressor with R410a while the standard price is closer to $80. Not sure what they are here after, unless the other guy was wrong and this is not R410a but R22. Have to check the model.

User avatar
ecureilx
Immortal
Immortal
Posts: 9790
Joined: Fri, 20 Aug 2010

Re: Aircon servicing every 3 months - Tenant Pay?

Postby ecureilx » Tue, 12 Apr 2016 9:53 pm

x9200 wrote:There are also flanges and tubes and a vibrating motor in a standard fridge. If something is done right it should not leak. My bet is, most leaks occur as the results of lousy repair / maintenance. In our first apartment where we lived or 7y, none of the units has ever been in need for the top up. In the current apartment there was no problems with it for 2 years and then I engaged the current company and almost every visit they "discover" something new. What is interesting, they wanted me to pay $40 to top up a single compressor with R410a while the standard price is closer to $80. Not sure what they are here after, unless the other guy was wrong and this is not R410a but R22. Have to check the model.


The point is, again, in a fridge or window aircon or casement, the tubes and flanges are welded. Unlike split units where tubes are run and connected. Hence the expected gas leak.

Back to the regular discovery of something wrong, I seen that, not just in Aircon but in lot of areas where the guys price themselves too cheap, they need to 'upsell' the service to survive.

About R22, R22 contributes to global warming, and is phased out in lot of western countries, and Singapore should be no exemption. R410a is supposedly "GREEN'

you can't top up a R22 Aircon system with R410a (can't recall the specifics but one of them damages the system). If done wrongly, the system has to be flushed with nitrogen and re-gassed.

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Tue, 12 Apr 2016 10:47 pm

ecureilx wrote:About R22, R22 contributes to global warming, and is phased out in lot of western countries, and Singapore should be no exemption. R410a is supposedly "GREEN'

It doesn't matter. I am talking about a 10y aircon. If it uses R22 it still uses it. The legal ban is for the currently sold units, not the ones installed before the regulations kicked in.

ecureilx wrote:Ok, unless technology changed, low gas or no gas used to lead to compressor seizing up, in older Split Aircons.


That simply means that the compressor is lubricated by the refrigerant liquid. Ok, but this should also mean the aircon first significantly loses the cooling power as there should be not enough liquid refrigerant to circulate to the indoor units. Is that correct?

ecureilx wrote:That's what I learnt as an apprentice in air con company. I am sure since then technology changed to detected low gas etc, but I also doubt cheaper aircons have such safety feature. Yes, the same compressor that's generally guaranteed for 5 year ;)


Such sensors are or could be based on heat to mass transfer and my guess is the whole device + integration would be less than $20 so dirty cheap.

ecureilx wrote:To be honest, the gas issue is one problem you can always avoid with a Window / Casement unit (no tubes / pipes / joints - no leaks but bear with higher noise in return), or engage a different contractor who can use a gas leak detector at the joints to really check for leaks and double seal them. If the gas leaks constantly, the contractor lacks proper gas detection equipment.

I talked to like 4 companies about the potential issue and all what they were able to propose was the pressurization test costing $300-500. I don't see any way how this test would benefit me unless the leakage is catastrophic.

User avatar
ecureilx
Immortal
Immortal
Posts: 9790
Joined: Fri, 20 Aug 2010

Re: Aircon servicing every 3 months - Tenant Pay?

Postby ecureilx » Tue, 12 Apr 2016 10:57 pm

x9200 wrote:
ecureilx wrote:About R22, R22 contributes to global warming, and is phased out in lot of western countries, and Singapore should be no exemption. R410a is supposedly "GREEN'

It doesn't matter. I am talking about a 10y aircon. If it uses R22 it still uses it. The legal ban is for the currently sold units, not the ones installed before the regulations kicked in.


Agreed

ecureilx wrote:Ok, unless technology changed, low gas or no gas used to lead to compressor seizing up, in older Split Aircons.


That simply means that the compressor is lubricated by the refrigerant liquid. Ok, but this should also mean the aircon first significantly loses the cooling power as there should be not enough liquid refrigerant to circulate to the indoor units. Is that correct?


not Exactly, I don't remember the rationale, but Compressors do have their own oil sump, But prolonged operation without gas, maybe dries up the oil ? Honestly I cant' remember that.

ecureilx wrote:That's what I learnt as an apprentice in air con company. I am sure since then technology changed to detected low gas etc, but I also doubt cheaper aircons have such safety feature. Yes, the same compressor that's generally guaranteed for 5 year ;)


Such sensors are or could be based on heat to mass transfer and my guess is the whole device + integration would be less than $20 so dirty cheap.


The question is, is your aircon currently equipped with such a sensor :-k :roll:

PS, ever heard of Chip Detector in Gear boxes ? ? :D Your thinking is in line with similar concepts ;)

ecureilx wrote:To be honest, the gas issue is one problem you can always avoid with a Window / Casement unit (no tubes / pipes / joints - no leaks but bear with higher noise in return), or engage a different contractor who can use a gas leak detector at the joints to really check for leaks and double seal them. If the gas leaks constantly, the contractor lacks proper gas detection equipment.

I talked to like 4 companies about the potential issue and all what they were able to propose was the pressurization test costing $300-500. I don't see any way how this test would benefit me unless the leakage is catastrophic.


Ok, when I did apprentice, I don't remember gas detection work being optional. After all, if the worker can't guarantee there is no leak or extremely low leak, the customer will call back and make us do it again and again. Ah, well, this is Singapore. Such expectations aren't there I guess ](*,)

I just suspect it's just the case of extremely low-pricing and upselling the services !

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Wed, 13 Apr 2016 8:45 am

ecureilx wrote:not Exactly, I don't remember the rationale, but Compressors do have their own oil sump, But prolonged operation without gas, maybe dries up the oil ? Honestly I cant' remember that.

Prolonged operation without gas would be easy to spot - my earlier point on no cooling.

ecureilx wrote:The question is, is your aircon currently equipped with such a sensor :-k :roll:

You earlier point seems to suggest the sensor may not be there in cheaper appliances, why my answer was (translated), if it is not there, the cost should not be a reason.

ecureilx wrote:PS, ever heard of Chip Detector in Gear boxes ? ? :D Your thinking is in line with similar concepts ;)


I am not sure, but chip detection appears to be about debris that indicate a damage or may lead to a mechanical damage. It's a different thing.

But... I encountered one compressor (system 3) where the fan was down and this compressor, if allowed sufficient time to cool down, later kicked off as per normal and worked cooling for a few minutes. This IMHO suggests there is an overheating sensor in the compressor.

ecureilx wrote:Ok, when I did apprentice, I don't remember gas detection work being optional. After all, if the worker can't guarantee there is no leak or extremely low leak, the customer will call back and make us do it again and again. Ah, well, this is Singapore. Such expectations aren't there I guess ](*,)

I just suspect it's just the case of extremely low-pricing and upselling the services !

They are not extremely low priced. They are at the medium band. This is just the overall service quality in Singapore with the rip off culture. I have another contractor, that I am slowly switching over to. This is a single guy company with an apprentice. I had him once to diagnose a problem and you can see from talking to him that he is professional and don't try to sell you some BS. He is a bit more expensive than my current contractor and you know what, the waiting time to get his services is at this moment 2.5 month for a week day slot and half a year for a Saturday slot. This I think tells a lot both about this guy and the rest of the companies around.

BBCWatcher
Editor
Editor
Posts: 1035
Joined: Sun, 13 Sep 2015

Re: Aircon servicing every 3 months - Tenant Pay?

Postby BBCWatcher » Wed, 13 Apr 2016 9:33 am

ecureilx wrote:I have my friend doing Aircon and such work in Dubai and around there and they were in fact confused about the quarterly serving in Singapore. And don't tell me Singapore is more hotter than Middle East.

No, but Singapore is more humid. Average relative humidity in Dubai is about 60 while in Singapore it's about 84. Air conditioning experts would know whether that difference matters.

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Wed, 13 Apr 2016 11:35 am

BBCWatcher wrote:
ecureilx wrote:I have my friend doing Aircon and such work in Dubai and around there and they were in fact confused about the quarterly serving in Singapore. And don't tell me Singapore is more hotter than Middle East.

No, but Singapore is more humid. Average relative humidity in Dubai is about 60 while in Singapore it's about 84. Air conditioning experts would know whether that difference matters.

How about Houston. TX? I actually intended to argue with what SE earlier said based exactly on that parameter (the humidity) but I checked the yearly profiles and decided to shut up.

User avatar
Strong Eagle
Moderator
Moderator
Posts: 10567
Joined: Sat, 10 Jul 2004
Location: Off The Red Dot
Contact:

Re: Aircon servicing every 3 months - Tenant Pay?

Postby Strong Eagle » Wed, 13 Apr 2016 11:38 am

ecureilx wrote:I have my friend doing Aircon and such work in Dubai and around there and they were in fact confused about the quarterly serving in Singapore. And don't tell me Singapore is more hotter than Middle East.


Once again, the quarterly servicing of aircon units is unnecessary and a scam. Once a YEAR checks are recommended by aircon companies in Houston, and:

a) The humidity is equivalent or higher than Singapore.
b) The temperatures in the summer are much higher with a much higher work load on the aircon... can easily run 18 out of 24 hours.
c) If you actually cared, you could take the cover off the indoor unit and vacuum the dust of the coils.
d) If you actually cared, you could use a garden hose to squirt a bit of water into the evap coil drain tube... just to remove the mold that might form.

It's a ripoff, plain and simple. Why would your aircon need servicing every 3 months when your refrigerator runs for years with benign neglect? They work exactly the same way.

User avatar
Strong Eagle
Moderator
Moderator
Posts: 10567
Joined: Sat, 10 Jul 2004
Location: Off The Red Dot
Contact:

Re: Aircon servicing every 3 months - Tenant Pay?

Postby Strong Eagle » Wed, 13 Apr 2016 11:43 am

BBCWatcher wrote:No, but Singapore is more humid. Average relative humidity in Dubai is about 60 while in Singapore it's about 84. Air conditioning experts would know whether that difference matters.


It doesn't matter. It does matter in terms of overall heat transfer but aircon sizing includes the humidity factor.

Otherwise, your aircon could care less if its 60 or 80 or 90 percent humidity.

Over the long haul, what kills air conditioners, especially the condenser unit outside, is pollution that gradually causes the typically aluminum radiator fins to oxidize.

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Wed, 13 Apr 2016 12:07 pm

Strong Eagle wrote:Over the long haul, what kills air conditioners, especially the condenser unit outside, is pollution that gradually causes the typically aluminum radiator fins to oxidize.

Safer to say corrode, but I don't think it's the case in Singapore. From my limited experience its often a failure of the electronic parts. Heating of any PCB with thermal cycling for 10y or more takes its toll.

User avatar
ecureilx
Immortal
Immortal
Posts: 9790
Joined: Fri, 20 Aug 2010

Re: Aircon servicing every 3 months - Tenant Pay?

Postby ecureilx » Wed, 13 Apr 2016 3:27 pm

Strong Eagle wrote:It doesn't matter. It does matter in terms of overall heat transfer but aircon sizing includes the humidity factor.

Otherwise, your aircon could care less if its 60 or 80 or 90 percent humidity.

Over the long haul, what kills air conditioners, especially the condenser unit outside, is pollution that gradually causes the typically aluminum radiator fins to oxidize.


The only reason I can see humidity as a factor is the dust starting to clog the fins.

And yes, I heard of Aluminium Rot :)

x9200 wrote:I am not sure, but chip detection appears to be about debris that indicate a damage or may lead to a mechanical damage. It's a different thing.

But... I encountered one compressor (system 3) where the fan was down and this compressor, if allowed sufficient time to cool down, later kicked off as per normal and worked cooling for a few minutes. This IMHO suggests there is an overheating sensor in the compressor.


The chip detector thing suddenly popped up, as a possible detection solution, but wouldn't be worth the cost, unless the compressor is spinning and flying.

As for over heating, there's a thermal relay, but again, I have no clue if that will prevent a compressor seize up.

Then again, when those days it was just sleeve and rotary compressors. I am sure technology has advanced and introduced newer and safer types.

User avatar
x9200
Moderator
Moderator
Posts: 9288
Joined: Mon, 07 Sep 2009
Location: Singapore

Re: Aircon servicing every 3 months - Tenant Pay?

Postby x9200 » Wed, 13 Apr 2016 7:57 pm

One more technical question: if the aircon is not used, can the gas still leak out? I am basically asking if there is any shut off valve between the compressor and the piping.


  • Similar Topics
    Replies
    Views
    Last post

Return to “General Discussions”

Who is online

Users browsing this forum: No registered users and 3 guests