New development or landed where pipes can be easily removed should always go for individually insulated piping. Condos are trickier especially when tier are existing pipes laid unless exposed PVC casements are used and the pipes are easy to remove.

Based on the posting, reusing old pipes is ok so long the necessary precautions are taken. What is different is that the pipes offer a lower margin of safety. Leak test and pipe purge are needed as the R410a compressor oil could be incompatible with what's used before. Some of my AC points are using old piping but they are installed in the early part of the 90s..The pipes are still good and R410a inverters are used. Touch wood they are still working ok.

You may want to have the AC guy inspect the drainage pipe and see if it can be given a once over. No point hacking unless type redoing the toilet. For mould prevention, run the fan for 2 hours before shutting down (use off timer on remote) or in AC equipped with clean mode, it will automatically handle it for you once activated.

This post has been edited by halcyon27: Jan 18 2018, 02:54 PM

That's the protocol.

Long story...a lot has happened...read from here onwards.

Supply availability is one thing but the main thing is whether the AC installers overall are up to date in handling this gas. As it's "mildly flammable", it warrants those who are responsible in carrying out installation work know how to handle it safely.

This is typically the skilled handler lag every time a newer gas with different handling characteristics is introduced to replace an existing one. The installers needs to update his skill to safely handle it.

This post has been edited by halcyon27: Feb 6 2018, 10:42 AM

Describe the hall. Is it a separate living room with dining behind the back wall connected through a door or it's a large open space with a defined dining zone, living zone and possibly kitchen? The latter should treat these spaces as one room.

Then use that area as the basis of determining the HP to use. See here. Note that the forumer's home ceiling is high enough to support ceiling air cond (min 11' gross). Also here.

This post has been edited by halcyon27: Feb 9 2018, 09:05 AM

How large the combined area? How long by how wide in feet?

Well, go measure and use the formula I posted. That will give you a rough idea how much cooling that space will need.

Piping got or not?

This post has been edited by halcyon27: Feb 9 2018, 01:41 PM

Ok, go measure first how wide, deep the area and how high the ceiling. Living area to dining area got staircase up/down or none (level from living to dining area).

This post has been edited by halcyon27: Feb 9 2018, 01:49 PM

House front face which direction? Single or double storey?

Living area to dining need to climb small staircase or not?

Ok, that's good info for a start to help us along except direction faced.

For that one, I meant the house front, which compass direction is it facing? every morning the sun rises from where:
A. directly from the front of the house (east)
B. from the left (south)
C. directly from the back of the house (west)
D. from the right side (north)
E. Somewhere in between one of the four main directions above? E.g. A&B (south east), B&C (south west), C&D (north west) or A&D (north east).

After you measure the width and depth of the hall, we can start to know what kind of AC HP needed to cool it. Should be in feet and inches or meter doesn't matter. Remember the height as well.

This post has been edited by halcyon27: Feb 9 2018, 04:17 PM

York, which was bought over by Johnson Controls which also acquired Hitachi Malaysia AC division. Underlying tech is from Hitachi but brand name is York with their reach nationwide.

Sharp R32 inverter esp for parents room. Healthier and indirect air flow that blow upwards towards ceiling and not at occupants.

Sharp has been doing this since 2007-2008. In most other countries it's called Coanda cool. It's named after the aerodynamicist who discovered this natural phenomenon named after him as the Coanda effect. You don't need a sky series to employ this method. I use this to hit a ceiling fan set at 28°C and 2 speed. The wind chill effect induced is quite pleasant. My kids sleep under this in the old home. Additionally the Sharp has the crucial clean mode which reduces mould growth in the indoor unit and the drain. Turn it on after every use should lengthen the indoor service interval.

This post has been edited by halcyon27: Feb 23 2018, 08:56 PM

Inverter saves from the start. Precise temperature regulation vs non inverter. The 8 hours thingy has to do with payback on investment considering that they cost 50% higher than non inverters due to the electronics and inverter components and if it's DC motor based, magnets too.

Say a non-inverter consumes 8kW units of electricity per day. One that saves 50% would only consume 4kWh units. The cost part is debatable as it depends on how much total units consumed per month and the difference in the tariff bracket avoided.

Payback is accelerated if the usage is as electricity usage is an operationally long term cost.

This post has been edited by halcyon27: Feb 24 2018, 04:56 PM

Compatible. Flush the pipes if installation manual directs as such before installing.

All the brands mentioned are ok. Bedrooms use 1hp ok also.

For the area where is open layout for living, dining and kitchen, assuming it's 500sqf total, you can use heat load factor of 60 for non-top floor condos. See here on how it's used.

500sqf x 60 BTUh/sqf = 30,000BTUh

That's the realm of 3.5HP. So either go for 2.5 or 3HP. Place it over the wall that allows blowing in from front to back. There are long throw ACs esp Mitsubishi Electric, Sharp. York also ok.

The reason is because in my old landed, living and dining is open layout as well and it's 500+sqf. Including the kitchen would be 650sqf. The 2HP Daikin inverter (18,000BTU) in the living already struggling. 18,000BTU just nice for say up to 300-330sqf but the living area in my old house already close to 400sqf. A 2.5 or 3HP for your place would cool it down faster and maintain 26-28°C easier too and lower if there's more people. In mine, I could hear the AC like as if struggling esp on 26-27°C AUTO. The problem is it takes a long while to each this and sometimes my spouse just put it on high speed fan at 20°C but it would never reach this temp of course.

This post has been edited by halcyon27: Mar 9 2018, 10:36 AM

AC contractor can have their own biases..but Sharp is within the top 5 in Vietnam and in India only inverters are sold. The next gen model, the VX series rollout will feature IOT.

Inverters are variable frequency thus will have those plus magnets if it's DC motor. Not asking you to buy Sharp just highlighting that long room layouts are known to AC manufacturers esp Mitsubishi Electric esp their older Starmex models and Sharp. Just a press of a button will throw the air from living balcony wall side to the dining area further in. Seen it use in friends house.

This post has been edited by halcyon27: Mar 9 2018, 08:45 PM

It depends on the model of the AC chosen. Sometimes even for the same HP, its spec calls for a bigger piping usually seen for the next higher HP AC. The opposite is also true. Some models, like Daikin can use even a pipe usually spec'ed for lower HP of other brand models e.g. their 2HP over 1.5HP or 3HP over 2.5HP of other brand models.

Get your regular AC guy to tell you the pipe size (record them down) of each AC point by their liquid (narrower) + gas (wider) e.g. 1/4" + 3/8" (standard 1HP) or 1/4"or 3/8" + 1/2" (1.5HP or 2HP) or 3/8" or 1/2" + 5/8" (2.5HP typically), etc. Once you know the pipe size compare that to the Daikin model that matches. For the same HP, if the pipes exceed that which was specified, it can be used but not the other way round...ie it cannot be smaller than the pipe size specified for the model. Ensure pipes are leak free esp if using older pipes for R32 gas which is mildly flammable. Best is to use newer pipes.

This post has been edited by halcyon27: Mar 9 2018, 11:57 PM

I've experienced what you've went through. Cooling mode is dry plus cold. The appliance conditions the air by modifying temperature but invariably moisture is removed and thus humidity is lowered.

In my old condo, even at the highest blower horizontal position, I still get the AC blowing near my face. Nowadays, I use AC that can blow towards the ceiling literally.

But, our lungs needs to be moist to facilitate air exchange hence prolonged use is detrimental if body is not sufficiently rehydrated. If not addressed asthma or bronchitis can set in. Dry throat is warning sign...too dry for too long. After seeing a doctor, I just did what he ordered. Drink more water throughout the day and according to him keep it not too dry and combine it with the ceiling fan.

After experimenting, the healthiest is 28°C AUTO coupled with two speed ceiling fan with the air blown upwards towards the ceiling and not at the occupant.

It may sound counter-intuitive, but it's the moving ceiling fan that induces the windchill which we perceive as cold. Lowest I would set is 27°C AUTO but for that I will have to drink lots of water before going to bed. Lower temperaturelike 24-25°C I would only use when awake in the day when it's markedly warmer.

The parameter to maintain is the relative humidity as measured with a hygrometer..how much moisture is in the air. Try to keep it within 60-70% RH at 28°C when sleeping. Inverters can precisely control this better than non inverters. Lower at 50-60% RH is ok whilst awake. If the room can maintain this humidity, forgo the AC but turn up the ceiling fan. The GP that i saw long ago told it like this: "This is the tropics so blanket thickness and clothing doesn't need to be thick or long sleeved. Or use the cotton sarong like how its always done back in the kampung."

This post has been edited by halcyon27: Mar 27 2018, 09:48 PM