I've pmed you one based in Kajang/Semenyih. Not sure if that's near. The one who did my kids room inverter with Smartco Paircoil piping is no longer in this line having injured himself in 2013. The contact is the still active colleague that he had given me in 2015.

One way you can ask for installers contact is to go to AC/ refrigeration equipment suppliers around the area and ask each to recommend. It's good to have two or three that are near the locale where you're located but to vet if they're good is purely by luck. I've to admit that the one I engaged the first time was very good, honest and conscientious but is limited to within Klang Valley esp MK, PJ, Subang and Puchong.

This post has been edited by halcyon27: Oct 20 2017, 12:28 PM

The hot air as a result of the rejected heat must go somewhere. If not mistaken, they have a ducting which must position elsewhere to vent the rejected heat?

See the 360° view of the product on what I mean here. Where it's suitable would be the condo balcony or a landed home balcony.

This post has been edited by halcyon27: Oct 20 2017, 03:49 PM

Read the below documents as found here and here. From them, derive your findings and conclusion.

What's the room area and how high is the ceiling from the floor? Is the dwelling landed (if so most likely end lot or corner and any insulation in the roof) or condo (top floor or intermediate between floors)? Which is the orientation of each of three walls?

Very unusually large living room with low ceiling..sounds almost like some kind of modified cargo container dwelling. This is landed or condo?

Can you describe this space a bit more. Is this landed, condo or some other What's it made of: masonry (red clay brick), precast reinforced concrete, wood, mud, corrugated zinc alume sheet, glass, stainless steel sheet, etc.

8ft height is undesirable as the hot air zone is very perceptible at all times. Best is it's 9 ft minimum or as high as possible if less. It needs a few baby ceiling fans spaced out to where occupant zones are. No down light should be used and if it's 8ft due to plaster ceiling, suggest that as much as all that space can be reclaimed if possible say about 4" drop rather than 6" or 12" drop.

Ok. Sounds like you're based very near SG ie JB. I would like to know also where to source for Armacell's products like Arma flex if you're actually based in Klang Valley. Should go for 1/2" or even 3/4" insulation thickness for the outside and 1/2" or 3/8" thickness inside the FCU. Be sure it's encased in white trunking to protect it on the outside from the elements also until the last part where it's exposed to reach the compressor. Hope it goes well and if you can let us know how it went and feasts our eyes with pictures.

Update: see the pictures in this blog as to the extent taken to insulate even outdoors with trunking casing.

This post has been edited by halcyon27: Oct 23 2017, 11:32 AM

What kind of roofing material? Corrugated zinc or concrete tiles? Sorry to hear this predicament but all this is classic solar baking oven 101. Perfect orientation all round with the right choice of materials.

Long term: roof insulation only 1/4 of the equation. The other 3 walls should have some sort of shading to mitigate insolation (solar radiation). There are many approaches to this you can use if the budget allows. Otherwise using AC is a permanent thing.

Roof - tile roof should employ Monier cool roof solution or Parsec Thetmobrite 3 radiant barrier foil, services provided by Dynaspec. Corrugated zinc roof should use a steel roof sheet with a fire retardant treated polyurethane padding underside for sound and heat insulation. Like this.

Walls is the main challenge as there are 3 of them. The simplest one is the non side wall: use wooden blinds that we see along most old streets out of town. The side walls will present a challenge as they are sloping. Perhaps the same can be employed with noticeable breaks. The are modern versions of that using fixed aluminium louvre vanes that shades the wall from the excessive heat. If there's any side that faces the garden if there's one, a trellis network that will allow creepy plants to climb can be a way of shading.

The other way is to use those steel roofing sheet with the fire retardant polyurethane padding underneath and attach that to the exposed walls like stucco. Perhaps regularly spaced square aluminium rods would be attached like how the western construction use firring strips. So long as rain cannot intrude somewhere that will encourage mould growth underneath it should be ok. This would prevent the heat from getting in. To augment that, before attaching that on, employ those double bubble aluminium radiant foil as a stucco underneath the steel roofing sheet with the fire retardant polyurethane padding. So it's like insulated adding skin to the brick wall. There must be a layer of air between the brick and outer insulation so the aluminium square rods acts as that. Care must be taken to prevent water intrusion and allow for moisture evaporation also. Hope you can envision what I'm describing.

My opinion is insulate first as no matter how powerful an AC, the operating cost long term definitely will add up. With this method, a 1hp can be spec and perhaps only turned on just in dry mode.

Without it, based on a rough calculation based on this post , the cooling load derived is about 20,000-21000BTU/hr or even more. That's a 2.5hp AC to deal with the peak load. I've known people in the east coast who sleep under similar conditions like top floor of apartments underneath the bare concrete roofing deck and their experience and sharing tells me out ain't healthy in the long run. Have to drink lots of water as they sleep under AC full blast and have to wake up to turn it off around 4am.

This post has been edited by halcyon27: Oct 23 2017, 10:10 AM

More like 3-4HP. Conservative calculation in this post to 30000BTU/hr which is within the realm of a 3HP. Perhaps 2 units with 2 or 2.5hp covering the living room and 1 to 1.5hp covering the dining one.

If you can redo the plaster ceiling like I suggested, LED down lights with built in drivers like this one are only 10-15mm thick. A 3-4" ceiling drop should suffice. The increase of 4" in ceiling height from 8' 4" also lends to a wider light throw angle.

This post has been edited by halcyon27: Oct 23 2017, 12:45 PM

What's the area of living area and dining area separately? Any openable partitions between them? Based on this post, total cooling load could be just over 28,000BTU/hr. Something in the realm of 3hp total but to apportion, have to see what's the total area based on the dimension of each space.

The AC installer will need to inspect the developer piping and do a leak test (2 weeks) to check if it's leaking. Also based the pipe sizes, manufacturers AC matching that spec would be your only choice. The pipes can exceed the mfg model spec but not the other way round.

This post has been edited by halcyon27: Oct 23 2017, 12:18 PM

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This post has been edited by halcyon27: Oct 23 2017, 12:20 PM

Get them to check as they do pressure leak test. Then ask them the pipe sizes. Write it down and post it back here.

How far do these piping run to the outside?

This post has been edited by halcyon27: Oct 23 2017, 12:23 PM

2HP perhaps for now, only Daikin. Sharp has it up to 1.5HP (AHXPnnUXD). If going that route the pipes better be good as it's mildly flammable. They removed the flame retardant blend combined with it from R410a.

They will just fill it with gas probably nitrogen and seal the pipe under pressure on both ends as it should be when charged with refrigerant and take a reading. Then after two weeks take a reading to compare with the previous.

Not all would do. I only specified for it on existing embedded piping during renovation.

This post has been edited by halcyon27: Oct 24 2017, 11:18 AM

9ft ceiling too low for cassette unless it's net height? 10 ft minimum so that when plaster 1ft there's 9ft of net ceiling height. For 9ft after plaster net 8ft left. Ideal is 11ft ceiling height.

Is dining and kitchen combined also or separated by a wall and door? Is this landed or condo? Use this post as a guideline. You may need two wall mounted split units. At least 2.5hp in living and at least 1.5hp in dining assuming living room is about 60% of the space. More if factors suggest higher cooling load required.

This post has been edited by halcyon27: Oct 27 2017, 07:26 AM

Ceiling AC clearance within the ceiling dictates how low the plaster ceiling should cover. Older models usually 11" but newer ones could be 9-10". It depends on the model. Even after that, there should be 1" gap from ceiling.

If you live in condo and there's no balcony or door accessible AC ledge to place the compressors, but rely on the space outside through the window, that window if it has a divider will limit how wide a compressor can fit through. In such cases, perhaps 2 or 3 units of 1 or 1.5hp or even possibly 2hp may fit through. The width of the gap determines what compressors can fit through. Not a problem with landed.

Alternatively, dining can be 1hp living can be 1.5hp but it all depends. Calculate and see based on the link given. If that space chun chun W,SW,NW facing, cooling load will be 20-30% higher. The calculation will give a rough estimate.

This post has been edited by halcyon27: Oct 28 2017, 08:54 AM

Might work to a certain extent. Awning only meant to shade or prevent glare from the sun's position during the day. It delays the direct exposure until a certain angle later in the afternoon. A louvre cladding over the exposed areas will prevent that at all angles. Maybe a combination of both. The same roof cladding link I gave can also be applied on the walls using furring strips such that it becomes a stucco with an air gap behind it. Then the awning prevents water intrusion from the top of the cladding.

All air cond dehumidifies. It's how the air becomes dryer....through dehumidification. Are you looking for a humidifier in this instance? To have the room air more moist than dry? Is she asthmatic?

This post has been edited by halcyon27: Nov 2 2017, 04:27 PM

Calculate the cooling load first. That will determine the HP required. If cooling load within the 1.5HP (12500-14500BTU/hr), use back 1.5HP. You can use 1HP if it's lower. Any higher, check the piping spec and see which higher HP model matches. But if the piping are meant for non inverter esp older refrigerant (R22), then change the piping to withstand higher pressure from R410a/R32 gas. Don't reuse esp if the older AC uses R22 gas. Safer option is to change the piping.

This post has been edited by halcyon27: Nov 2 2017, 09:21 PM

Yours landed or condo? Depends whether the current pipes are spec even for 1.75HP. What's the model of the older 1.5HP? If unsure, look for the model information either at the side or bottom of the blower unit. Sometime it will mention refrigerant whether R22 or R410a. If it's R22, better to change to thicker piping (0.81mm).

This post has been edited by halcyon27: Nov 3 2017, 09:00 AM