Dear DIY Members: I Shall Buy Air Conditioning!

[EmptyHead]

Dear members of the DIY forum,

I am sorry for one of these tedious threads, but I am not afraid to ask for help and advice.

A perfect storm is brewing: the wife thinks she knows exactly which type of A/C unit we should buy, despite never having had A/C in her life. Alas, she even said, "We'll just ask guy in shop, he'll know"

Well, ladies and gentlemen, I think you can appreciate the trouble that is coming my way, if i don't act!

Act, I shall. To Thaivisa I go......

These are the important points:

• It is a spare/guest room.
• It isn't likely to get used much more than a couple of hours occasionally in the hot season (maybe a bit more at night when my Eskimo-like relatives visit, which is seldom, thank god).
• The room is 4m x 4m x standard ceiling height (looks like 2.5m or slightly more)
• The room is west facing, so it gets the sun in the later half of day.
• No special insulation. Under the roof tiles there is a thin metallic sheet, supposed to repel heat or something.

I have read previous threads and most of the sensible posts came of our A/C experts, namely Naam with partners in crime Mogandave & Elkangorito, not to mention our electrical guru, Crossy.

So, the big questions that are keeping me up at night (It certainly ain't the wife):

1. Does size (BTU) matter? (Don't wanna ask the guy in the store that one)
2. To go inverter or not to go inverter? (That is the question)
3. Any brand you can recommended from several years of experience with them?

Thank you all for your time and patience. I tried my best to make such a boring post entertaining and also to try to manipulate compel you to help me.

And if i have missed some important points, please don't hesitate to publicly berate me, I am big boy and I can take it well.

Edited February 26, 2015 by EmptyHead

[Daffy D]

Let the wife choose.

If you don't you will never hear the end of it.

[EmptyHead]

A wise man, you are.

My Dad tells me the same thing.

But I shalln't, for my little room must be appropriately air conditioned.

[eyecatcher]

Yes let the wife choose but do it in such a way that she gets the knowledge you glean from this thread.

I will start with my basic rules of thumb.

reckon on 600btu/m2 for a lower floor and add another 300btu/m2 for upper floor.

in your case a bungalow? I would err on the side of 900btu/m2 to be safe. so 16m2 room x 900= 14400btu.

When you go shopping you just make sure the wife has the info gleaned from this thread.

you will notice most models size their units in 9k,12k18k;22k but for some reason Haier(who?) do a 14k, 24k and LG do a 17k just to be awkward.

If you room will only get moderate use I would go for a 12k btu. Bumping up to 18k could also be a difference of an extra 10k baht.

the big stores will charge 500bt installation if the compressor unit is floor mounted and 800bt if its wall mounted and included in this you will get a standard 15m of electric cable and 4m of copper piping. so think about the distance between the two units.

Also remember to site it high enough to enable you to fit a curtain rail under. you will regret that if you forget about it and decide to have curtains later.

well here endeth my advice; I will let the sparkies take over on their advice.

[cornishcarlos]

The most expensive and biggest in the shop. Salesman happy, wife happy, eskimos happy

[Crossy]

A bedroom so only occupied at night, not doing battle with sunshine.

A guest room so only used occasionally, don't bother with an inverter unit.

16m² @ 600 BTU per m² = 9600 BTU, get the next size up.

If the room gets really warm during the day maybe one size bigger to cool more rapidly but be aware that a significantly oversized unit will not produce much drying effect and could leave you feeling clammy.

[HuckAuffority]

Do not buy an oversized unit if its only for rare use or if the inhabitants want it like an igloo. It will only waste more power and the room will cool down eventually.

If it is not getting used for months at a time, turn off the power to it to stop the sump heaters on the compressor wasting power.

As far as brands go, you get what you pay for.

Daikin or Mitsubishi Electric.

Do not buy chinese.

[IMHO]

1. Does size (BTU) matter? (Don't wanna ask the guy in the store that one)
2. To go inverter or not to go inverter? (That is the question)
3. Any brand you can recommended from several years of experience with them?

1. Yes, of course. Too small and it won't cool the room, too big and it will cost too much (to both buy and run).

2. No. Given the infrequency of use, you'll never get ROI on an inverter.

3. Given #2, any name brand will do.

Given the room has West facing glass, and you have guests that want lower than normal temperature deltas, you will definitely want a 12,000 BTU AC. Chose one from a name brand (Samsung, LG, Mitsubishi etc) with the best combination of price and warranty.

You should be able to get something for under 1 Baht/BTU.

Edited February 26, 2015 by IMHO

[cornishcarlos]

Interesting topic... On a related but side note, Crossy quotes 600 BTU/m2 but does this vary much depending on how well insulated the room is ?

Thai builds don't generally insulate too well.

[KittenKong]

I would never buy a non-inverter aircon, regardless of the amount of use it would get.

Even if the limited usage would not allow for large savings on electricity, inverters have other advantages like the absence of noise when they start up, and the general evenness of the cool air production. I would happily pay the extra for those comforts, and in fact the extra amount you pay may not be so big these days.

[EmptyHead]

Thank you all for your helpful posts!

I think we will go for a 12,000 BTU standard unit. Probably no need for anything bigger, especially if the cost could be significantly more. Though, we may use the A/C occasionally during the heat of the day for a couple of hours once in a while. Would a 12k standard unit still be fine if this were the case?

We'll see which brand the missus chooses. Daikin is a name i have never heard, but seems to get good reviews.

[HuckAuffority]

Daikin is a global leader. Expensive.

Plus they ONLY make air cons, thats why you have never heard of them.

For a long term investment, stay away from any brands you HAVE heard of that make "other" products.

eg: samsung, LG.

Im in the trade in Australia. My role is repairing breakdowns.

Daikins rarely do (when they do its expensive).

All other brands i can rely on to breakdown repeatedly.

I work on all branded systems and am in no way affiliated with Daikin.

If you can afford them, get it, have it installed properly, and forget about it.

[kamalabob2]

I will add that the two Daikin inverter I installed in 2008 have worked flawlessly and are quiet. The Panasonic Inverter is also very quiet. The lower end series LG I put in a guest room is just not built with the same "fit and finish" as the other brands. I noted this when the 400 baht per year air condition repair shop cleaning team is at work. The lower end LG series model makes quite a bit more noise than the Panasonic or Daikin inverter models. We do clean the filters with a standard vacuum once a month as we have to deal with crop ash when they burn fields near our home. The family owned air conditioning and major appliance shop near the Bamboo bar, Buriram Supply, I bought eight air conditioners from in Buriram has been good for after the sales service on the air conditioners. 100% of the wires, cables, pipes were hidden in the 12.5 and 7.5 AAC block walls and rendered over prior to painting the walls, so you do not see any pipe work on our house. Even the 32BTU standard Mitsubishi wall unit hangs safely on a 7.5 thick AAC block interior wall. The 24K Daiken inverter unit installed fine on an interior 7.5 thick AAC block wall. For the OP, the drain can be inside the house near a bathroom floor drain hidden under a sink counter, or it can be a drain outside. I did not install any compressors on our walls as we had the option to install them floor mounted on covered verandas and not necessarily on the same floor level as the room that was being air conditioned. I turn off the circuit breaker for units in rooms we do not use the air conditioning to save on the PEA bill.

[EmptyHead]

So dear members,

I was wrong about the size of our room. I paced it out the old fashioned way and came up with a size far larger than the reality..

My wife, however, has more brains and used a tape measure.

Its only 10sqm.

So we bought an LG 9000BTU standard unit for 10K Baht (with 5 years warranty), including delivery and installation.

So far so good. It works fine, but i haven't seen the electricity bill yet, lol.

My only fear now is that we will use it too often and waste money on electricity, in which case we probably should have gone for an inverter.

We are enjoying the novelty of it at the moment though.

Edited March 7, 2015 by EmptyHead

[Thian]

Buy a small Daikin inverter, problem solved.