How To Prepare For Air

[proximity]

How do I prepare a new build house for air? I want all the air compressors in one location. Do I need them to bring the electricity supply to the compressors outside, or to the inside units? Also, I assume I need to have them take the piping for the freon through the building?

[InterestedObserver]

If that is what you really want to pay for and install, then yes you would need to run the freon piping throughout the house. Both the inside fan/evaporator and outside compressor/condenser units would need an electrical supply and control connection. Not exactly an ideal way to aircon a house.

[proximity]

The plan is to have five multi split air conditioners. Why is it not ideal to have all the compressors located in the same place? This is how it is done in the house I currently rent and it is good as all the noise is contained to one side of the house that is not used for outdoor activities. It is a one-story house so there would be not too much of a loss in efficiency due to the length of the runs? I think the longest freon run would be about 20m with no rise.

Between the compressor and the unit I need the piping for freon and control wire? Then have electric supply both at the compressor and evap/fan units?

Edited September 4, 2011 by proximity

[Crossy]

You must check with the installation instructions, but most A/Cs only need power to either the outdoor unit or the indoor unit (I've seen both), power to the other is supplied over the cable that connects the two.

Again check the instructions of the units you intend using, but I think a 20m pipe run may be too long for many.

Run a separate power circuit for each compressor, use 2.5mm cable for up to about 24000 BTU on a 25A breaker, bigger units will need 4mm cable and a 32A breaker.

Have a read of this document http://www.palsonic.com.au/customer_service/aircon_instruct/Airmaster_AOS_Series_Split_Aircon_Manual.pdf one of several that Mr Google will turn up.

[kamalabob2]

You could consider having your builder, you and at least one independent air conditioning / appliance shop owner meet at your home and have the appliance shop owner take measurements VERY early in your building process. If you have"Q-Con" type exterior and interior walls you can consider having the pipes, wires all installed INTO the wall and then when the INITIAL rendering of the walls is done you will never know the pipes are in the walls.

We have two of our ground floor Daikin Inverter compressors actually installed on a rarely used 2nd floor balcony near a bathroom. In my limited experience of only eight split system a/c units in Thailand the better models (Inverters) are much more quiet than the lower end models both INSIDE and outside of the room. You can consider that a split system unit inside the house need not be installed on a wall that is an exterior wall, if they lay the piping in advance you could have air conditioning aimed at how you want in your room.

In our case we did not want any a/c compressors visible from the front yard and that was possible even though those front of the house rooms have a/c units. The builder was told by the a/c shop owner how much electricity was needed at what points and then the requirements of the specific wire and circuit breakers was all worked out for the electricians. It sounds more complicated than it is, the better Thai builders and better a/c shop owners do this process quite often. No need for ugly exterior pipes when they can be hidden.

Consider also where the water drainage for each interior a/c unit will go, it is possible to have the drain pipe of an a/c interior unit drain hidden under a bathroom sink counter floor drain. We made plenty of mistakes on this one house, but having the a/c piping all done in advance and all hidden from view was slick. I should have hidden more speaker cables in conduit PRIOR to the initial rendering as sure enough you can see where they speaker cable conduit is no mater how many times they render the wall after the initial rendering.

I recall the brochures of the various a/c units had enough English to understand electrical consumption, pipe specifications, db sound levels and I vividly recall how the length of the copper tubing was an issue for each unit and planned for in advance. The key was the builder and a/c shop owner working in advance, we did not select the actual a/c units until 9 month later, but all the piping and electrical cables were installed and hidden.

The DB level of some of the mainstream brand inverter units will be surprising low. 20 meter pipe run is WAY too long for any mainstream a/c unit we looked at. The electrical supply to each unit will perhaps come via electrical cables in your ceiling. A good independent a/c shop owner can answer your questions.

[Naam]

If that is what you really want to pay for and install, then yes you would need to run the freon piping throughout the house. Both the inside fan/evaporator and outside compressor/condenser units would need an electrical supply and control connection. Not exactly an ideal way to aircon a house.

sorry, but that's incorrect info. nowadays nearly all split units rout electricity from the inside unit to the outside unit. exceptions prove the rule but there is just one electric connection.

[Naam]

The plan is to have five multi split air conditioners. Why is it not ideal to have all the compressors located in the same place? This is how it is done in the house I currently rent and it is good as all the noise is contained to one side of the house that is not used for outdoor activities. It is a one-story house so there would be not too much of a loss in efficiency due to the length of the runs? I think the longest freon run would be about 20m with no rise.

Between the compressor and the unit I need the piping for freon and control wire? Then have electric supply both at the compressor and evap/fan units?

pipe lengths is the problem. longer pipes = less efficiency and higher pipe cost (copper price tripled since 2008!).

efficiency rule of thumb:

-each 4m = 5% efficiency loss when using adequate diameter.

-each 4m = 3% efficiency loss when using next size

note: efficiency loss of piping longer than 4-5m cannot be compensated completely by using infinite bigger pipe diameter. the latter is also limited by the compressor's ability to pump a certain refrigerant volume.

if you want aesthetics you have to pay for it.

[lopburi3]

All our split units have been electric inside and run from that unit outside. I believe last 9k Panasonic even had an AC plug to directly attach to wall outlet (removed to use normal breaker). Inside/outside units should be as close as possible as there is a lot of loss involved and even with normal insulation there will be a river of condensation so would not advise running more than needed inside house. Drains are a serious matter as most will become blocked at some point and if slant is not much that sometimes will become a common occurrence. And water overflowing from inside unit is not exactly good for what is below it.

As for having all outside units together they work by removing heat so if you are adding heat from multi units to a confined area the efficiency will decrease. Allow free flow of unheated air.

[Spoonman]

What not install a ducted AC system that you can turn on/off individual zones ?

[kamalabob2]

Posts 4, 6,7,8 are very correct. Once you see the price on the "central" units with long ducting and cassette in the ceiling output of the cool air you can see why only expensive hotels offer that system. The "normal" split system with the interior part not far from the exterior compressor is an excellent value in Thailand. Some of the newer models are quite energy efficient and very quiet. Even the price of a "multi split" unit, where one compressor can cool two rooms might not pencil out compared to individual split units. Once you determine the specific models you want for the rooms you will find the various shops can vary a HUGE amount in the price and how many "free" cleanings they will offer.

[InterestedObserver]

If that is what you really want to pay for and install, then yes you would need to run the freon piping throughout the house. Both the inside fan/evaporator and outside compressor/condenser units would need an electrical supply and control connection. Not exactly an ideal way to aircon a house.

sorry, but that's incorrect info. nowadays nearly all split units rout electricity from the inside unit to the outside unit. exceptions prove the rule but there is just one electric connection.

My reply was poorly worded. Certainly there is usually only one supply circuit breaker, but both units need electrical connections.

[Naam]

If that is what you really want to pay for and install, then yes you would need to run the freon piping throughout the house. Both the inside fan/evaporator and outside compressor/condenser units would need an electrical supply and control connection. Not exactly an ideal way to aircon a house.

sorry, but that's incorrect info. nowadays nearly all split units rout electricity from the inside unit to the outside unit. exceptions prove the rule but there is just one electric connection.

My reply was poorly worded. Certainly there is usually only one supply circuit breaker, but both units need electrical connections.

of course they need a connection. generally a relay in the outside unit is supplied with current from the inside unit which switches compressor and condenser fan (if aircooled).