Diy Servicing Of Old Air Conditioning Units

[gerryBScot]

Hi I live in an old rented concrete shell in Ratchaburi and our upstairs rooms have old a/c units installed that use up lots of electricity but struggle to keep the place cool. The external units also discharge water which isn't really a problem as the garden likes it. Anything I can do myself to improve their performance? Your help would be much appreciated. Chok dee krap

[GungaDin]

The only thing I can suggest is to keep the filters clean by washing them every 2 weeks.

[Carib]

Also check the outside unit for dirt build up in the exchanger, if so just hose/spray the unit through the exchanger.

[GungaDin]

^^^ ^^^

Stupid question: With the unit running or off?

[longball53098]

Pay a shop to come and check the refrigerant charge in the system. They will do all for a normal unit for about 500 baht.

[Carib]

^^^ ^^^

Stupid question: With the unit running or off?

If you are a nervous type, switch it off and unplug the power supply. If you have a steady hand and " know what you are doing" it doesnot matter.

Always better to unplug the power supply, although I must admit I never do. There may be an opening inside the unit so water-elecricity contact `could` happen.

Spray on the ribbed surface inside the housing, through the fan opening. The unit will dry when in use again.

[lopburi3]

It should only cost 4 or 500 baht to have someone come in and clear both inside and outside units/check them. If doing yourself a good hosing of the outside unit (against normal air flow) through the coils/fins is likely to loosen a lot of dirt that you can wash away and get it working more efficiently. Inside is best done by someone with equipment so about the only thing you can do there is use vac to get as much dirt as you can and always keep the filters clean.

[gerryBScot]

Thanks that is good advice; I reckon I'll pay someone to come in and check/service them as am none too familiar with the inside of these machines. The leaking is when the units are switched on!

[Carib]

The " leaking" is normal. Airconditioners remove the water from the circulating air. Warm air is more humid, cold air is more dry. Hence the " removal" of water. It is perfectly normal.

[sinewave]

if you install the largest size electricity meter they will spin slower thana lower amperage meter.

You may want to shade the outside unit if it is getting hit with direct sunlight.

Make sure the shop that charges your ac uses imported freon, some of the local stuff isnt very pure and has a high water content or whatever they put in to dilute it.

[Crossy]

if you install the largest size electricity meter they will spin slower thana lower amperage meter. TOTAL BULL

You may want to shade the outside unit if it is getting hit with direct sunlight. Possibly true

Make sure the shop that charges your ac uses imported freon, some of the local stuff isnt very pure and has a high water content or whatever they put in to dilute it. Source?

Edited April 5, 2009 by Crossy

[mdechgan]

if you install the largest size electricity meter they will spin slower thana lower amperage meter. TOTAL BULL

Well actually is does spin slower. A 15 amp meter will spin slower than a 5 amp meter at a constant load. It depends on the meter's Kh constant rating. Usually 7.2 to 16 KH per revolution. As an example (not true math) a 15 amp meter will spin at about 20 RPMs while a 5 amp meter will spin 33 RPMs while drawing 15 amps. However you will still get charged for the same amount for electricity used. It doesn't matter how fast the meter spins, you get charged the amount of revolutions x the constant.

You may want to shade the outside unit if it is getting hit with direct sunlight. Possibly true

Sunlight hitting condensing unit does, help but not as one would think. The amount of air that moves between the coils is too fast for sunlight to affect it. Its like a garden hose in direct sunlight, at full flow the water is still cool, but if the flow trickles the water becomes hot. However what is important is the ambient temperature. If the area around the unit is cool it helps the unit's efficiency greatly. If the shade makes the air around it cooler then it can't hurt.

Make sure the shop that charges your ac uses imported freon, some of the local stuff isnt very pure and has a high water content or whatever they put in to dilute it. Source?

I'm in the industy and their is some truth to this. Doesn't neccessarily mean local or imported, but most of the freon in BKK is really contaminated. You see those tanks on the back of the motorycles. During the refill processs they just move the freon from one tank to another. Air definately gets mixed with the freon during the refill process. Also during installation many mechanics don't properly purge or vac the system. Air in the system converts to water. However the condensing unit's freon filters trap and remove the water. So after awhile some systems will need a topup even though its a closed system.

[gouda]

saw a foam air conditioner cleaner in tesco, comes in a spray can

www.norca.co.th

haven't used it so no idea if it works or not

[lopburi3]

I would highly advise having someone do the complete clean for 500 baht or less. Inside fins should be pressure cleaned and the dirt should not go down the normal drain (which will happen with a foam cleaner I suspect). Drains get clogged very easily.

[mdechgan]

saw a foam air conditioner cleaner in tesco, comes in a spray can

www.norca.co.th

haven't used it so no idea if it works or not

This stuff is absolute crap. Doesn't work. Just makes the coils more oily and the mess everywhere. One has to physically remove the built up dust and fatty oily stuff.

[kamalabob2]

GerryBScot: Longball53098 and Lopburi3 are 100% correct in paying the 400 to 500 baht for a professional technician from a air conditioning shop to come to your home and clean the unit both inside and outside of your home. My word of caution is to not allow them to place a metal "trough" under your interior unit and spray liquid into the wall mounted unit. A better more professional solution is when they dismantle the interior unit and clean it in a better manner outside. The shop in Buriram we purchased our air conditioning units include the first two cleanings per unit free and then charge 500 baht per unit after the first year.

[GungaDin]

GerryBScot: Longball53098 and Lopburi3 are 100% correct in paying the 400 to 500 baht for a professional technician from a air conditioning shop to come to your home and clean the unit both inside and outside of your home. My word of caution is to not allow them to place a metal "trough" under your interior unit and spray liquid into the wall mounted unit. A better more professional solution is when they dismantle the interior unit and clean it in a better manner outside. The shop in Buriram we purchased our air conditioning units include the first two cleanings per unit free and then charge 500 baht per unit after the first year.

Well spotted, Bob.

Good advice!

I should have remembered that from previous encounters with AC service guys.

[ACAsia]

Hi,

Know the post is quite old, however hopefully this might get to you somehow when you next view

The Internal units are the ones supposed to create condensate when running in cooling mode, not the external unit. The external unit generally creates condensate when running in reverse-cycle (heating mode) so hopefully the system was not on heating when the unit was creating this water, as simply changing the mode to cool opeartion may have solved\this problem you are facing.

Also the service tech should use wo solutions, condencide (for the internal evaporator coil) and hydrocoil (for the condensing unit heat exchanger). There are variations on the branding, however both are designed for that specific task.

Also thing to check if there has been a "sudden" cooiling performance drop would be for oil around the service valves (where the refrigerant pipe-work connects) inetranlly and externally.

Internal filters must be clean and passable for air, as this would cause the evaporator to ice up, which the internal thermostat reads as the room temperature, therefore cutting the system out on the stat (thinking its done its job)

Many systems have simple (or even complex) fault diagnostics that can be run from the infra red controller or fixed controller, depending on make and model.

If you would like some advice running through this, please PM me.

I am posting as I am looking to set up an air conditioning company in Koh Samui next year with plenty of experience on both sides (installation and sales/business running)

Thanks

Si

[bangkokumpalumpa]

ok one things that I feel is important is the airflow, a lot of aircons are just bolted outside where ever it is easy to get to. the problem with this is the air tends to get HOT.

a good example of this was my apartment in bangkok that I rented, there were two aircons one on top of the other, these were on a tiny balcony, the problem was they didnt get nice clean fresh air, well as clean as bankok gets that is, it was like an oven out there.

so think about how the cool air is getting in and the hot air is getting out, you dont want the hot air going back into the unit as this just helps to pump up the electic bill. you can save a lot of money with some simple thought. if need be build a simple duct to allow the hot air to exit better. you may be supprised!