Air Conditioning Installation and Maintenance

[carbpow]

I got a call again from a friend here in the Philippines about an air con problem. He blew another PCB on his split unit. This follows another call from another friend who said his air con which was installed one year ago is not cooling as it was. Neither call surprised me. The installation of split units here in my experience do not meet the manufacturers installation instructions for one thing. The guy that blew another PCB on an older unit told me he had it cleaned regularly by the initial installer. He said they pressure washed it. There is so much wrong with pressure washing a condensing unit I cannot understand why it is still done, unless it is to kill air cons. It's like pressure washing your car while your laptop is open beside it. The fact that the new air con isn't cooling properly does not surprise me either. These guys pull a vacuum for about 30 minutes with no way to know if the vacuum is enough or holds to meet manufacturers instructions. Also, the units sold are in many cases greatly over-sized.

I talked to a manufacturer's rep who I have known for years in Japan about these issues. He said,"Well you must realize we make our money selling the units and parts. If the installer or service people do not follow directions it is not an issue for us as we cannot control them." So my advice to anyone installing a split air con system in the Philippines is to get a copy of the installation instructions from the installer and insist they follow the instructions and monitor them. You will save yourself a lot of money and headaches down the road.

[carbpow]

14 hours ago, carbpow said:

ISo my advice to anyone installing a split air con system in the Philippines is to get a copy of the installation instructions from the installer and insist they follow the instructions and monitor them. You will save yourself a lot of money and headaches down the road. 

The guy that lost 2 PCBs? Unit was not grounded.

[hk blues]

15 hours ago, carbpow said:

So my advice to anyone installing a split air con system in the Philippines is to get a copy of the installation instructions from the installer and insist they follow the instructions and monitor them. 

Easier said than done for many of us!  

[carbpow]

On 7/7/2020 at 1:14 PM, hk blues said:

Easier said than done for many of us!  

The installation instruction come with the unit you buy. They belong to the owner not the installed. It's pretty easy to follow along. I watched an installation recently for a guy. The installer didn't follow the instructions for evacuating the unit. I asked him why and he said"We don't do it that way."  As an authorized supplier of these units to you have some special permission from Carrier not to follow instructions or do you special instructions from Carrier?" After a consult with their office he said no it is just not they way we do it. So, we told him that would be OK as long as we don't have to make the final payment. They left, came back two weeks later with the proper tools to do the job and it was successfully installed. They were happy to have the new tools and knowledge.

[expatuk2014]

bought our Mitsubishi split A/C 3 years ago has been serviced each year by the installer company inside unit filters cleaned weekly and self cleaning every 3 days by myself bedroom temp on remote set at 29c temp at bed level goes as low as 24c its very fast at cooling ! 

[carbpow]

14 minutes ago, expatuk2014 said:

bought our Mitsubishi split A/C 3 years ago has been serviced each year by the installer company inside unit filters cleaned weekly and self cleaning every 3 days by myself bedroom temp on remote set at 29c temp at bed level goes as low as 24c its very fast at cooling ! 

I really like Mitsubishi units and wanted one but they didn't have multi-split at that time.

Units from Mitsubishi Electric [not Heavy] and Daikin are my first  choices with Panasonic being very close 2nd. The newer ones have coated PCBs to prevent damage from insects, lizards etc. If they are installed correctly, grounded,  proper torque on fittings, tubing flushed with nitrogen , vacuumed down to 500 micron and hold for 30 minutes they should last for many years.

[hk blues]

13 hours ago, carbpow said:

If they are installed correctly, grounded,  proper torque on fittings, tubing flushed with nitrogen , vacuumed down to 500 micron and hold for 30 minutes they should last for many years.

Again, I question how many of us "normal" people would first of all know this stuff and secondly be able to verify it was done and done correctly?  Many would like to think they could but... 

[Tommy T.]

2 hours ago, hk blues said:

Again, I question how many of us "normal" people would first of all know this stuff and secondly be able to verify it was done and done correctly?  Many would like to think they could but... 

HK, I think you are mostly right.

Many people would confirm that I am, indeed, abnormal, HK... But that's okay, I can live with that...

Many people are not familiar with A/C or a lot of other technical details involved with home construction and operation. However, after reading through installation guides for various things I have had "professionals" install, I found that much of it is truly readable. But it does take tenacity and a willingness to learn the processes. Also, the owner might try to not be afraid to ask "stupid questions?"

I guess that another way to approach what is suggested by the OP above, might be to find someone related or a friend or even another third party conversant with the technology to observe the work? Just a thought... I am definitely not expert in most of these things, but I have curiosity to try to learn and definitely to observe, especially when a lot of investment is involved. In the current house build - and the previous one many years ago in USA - I spent a lot of time observing, asking questions and researching to understand what the various trades-people were doing and why. I find here that, even armed with a minimum of knowledge, the workers seem to be a bit more on their toes regarding their work. L is knowledgeable because she had her own place constructed years ago. She is never afraid to get right up to these guys and ask piercing questions (but she is polite about it!). I believe it pays dividends to at least know what and how things are constructed and installed at a simple level...

Interestingly, A/C and refrigeration use exactly the same technology, the basics of which have not really changed for many years. A couple of hours perusing a manual, or - even better - researching using Kuya G - can yield an amazing amount of knowledge. Maybe I just have too much time on my hands to trust people to do proper work? Like I said already... not normal...

When the yacht was moored in Australia, we had a problem with the refrigeration. There was a really qualified expert working at his shop next to the marina. He came over, checked the system and found a leak. He then purged the system with liquid Freon (bad old days) and then proceeded to evacuate it with his vacuum pump. He was super busy always, working mostly on fishing boats. I watched all he did and asked questions all the while. He took a few minutes to explain some basics, and told me the steps and what to look for. He then left the vacuum pump running and his gauge set connected up.

After ensuring there were no more leaks, I then set to re-charge the system using his gear. To do so properly took more than half a day. Mostly it was just give a hit of gas and then observe while checking a few things from time to time. He was too busy to fiddle with that. So, I learned the basics and was able to apply them many years later when the occasional problem cropped up...

Edited July 9, 2020 by Tommy T.

[carbpow]

On 7/9/2020 at 11:19 AM, hk blues said:

Again, I question how many of us "normal" people would first of all know this stuff and secondly be able to verify it was done and done correctly?  Many would like to think they could

If any normal people are close to Lucena City in Quezon province need some help when a system is being installed I'd be happy to help. No charge. Just as schedule permits.

Edited July 11, 2020 by carbpow
spelling error

[carbpow]

I went to a Filipino friends house today who noticed my house seemed cooler than his yet my temperature was higher than his so he asked me if I would look at his air con. After looking at the specs of his air con and measuring the room I told him the problem is his air con is too big. This confused him until I explained that comfort is a function of temperature and humidity with humidity being the larger part. When an air conditioner runs it drops the temperature and removes moisture as the air gets cooler. If the air conditioner is over sized the temperature drops before the humidity has a chance to be removed. He said,"But I bought the size the supplier said I needed." I told him I am sure he did. The supplier in the Philippines is given a formula to calculate AC size but the formula only asks for the size of the room, how many people will occupy the room and the size of the windows. They get this formula from the supplier who gets it from the manufacturer. I have been told the formula is based on 4" hollow block walls, poorly sealed windows and many people in the room. This makes sense for the average purchaser. But if you have a house with better construction you will be sold a bigger unit than you need based on that formula.

When I was building my house the supplier told me I needed 2.5  hp of cooling just for the kitchen living area and another  2.5 hp for the upstairs for a total of 5 hp. My calculation showed I needed 3.5 as an absolute maximum for the house. They sold me the 3.5 hp system but said they would not guarantee it would cool. Not only does it cool it has saved me a lot of money over the 2 window units I had for just 2 rooms in my previous place.

My friend asked me how he could remedy his situation and we decided to turn off the upstairs ACs and let the oversized downstairs unit run a bit more. We'll see how that goes.