I have a dilemna and I will explain the problem: I have a living room and dining room which are an open floor plan, and I would like to have air conditiong in both roomscause simultanously because it is one large room. I have called four or five of the major retailers such as Home Pro, Siam TV, Power Buy, and each one of them have come to measure the area and I get different suggestions from them--and nothing seems logical to me.

I was told by one company that I need two 24,000 btu units running separately, another company said that I need a 28000 btu, and an 18,000 btu to cover the space. I told them that I wanted to cool both rooms at the same time, because it is actually one large room, so is the a dual compressor that has two fans and then two venting units where the cool air comes out of. Another company said that I only need one unit.

These people are supposed to be professional, and I would like to get some good advice as to how many btu's I really need, and if it could be done with one compressor unit and two fans. The stores coould not give me an answer.

I was wondering if there is an independent air condtioning contractor who can come over and give sound advice and either build a system for my rooms or tell me what really need to cool the rooms in the hot season.

I would appreciate any suggestions and advice from forum members.

I'm sure you can get some good advice here, but we'll need the total sq meters of the room. My guess is that you will need two separate units, one on each end of the room. Either two 24btu units or two 18btu units, all depends on the size of the room. The height of the ceiling might be a factor also, so please provide that too.

I'm sure you can get some good advice here, but we'll need the total sq meters of the room. My guess is that you will need two separate units, one on each end of the room. Either two 24btu units or two 18btu units, all depends on the size of the room. The height of the ceiling might be a factor also, so please provide that too.

The rooms are approximately 5 metres by 4 metres, and 5 metres by three metres. There is a cathedral ceiling going up about 5 metres over the entire area, also stairs and a hallway going up to the second floor.

I was hoping that I could get one outside condenser unit that controls two fans at both ends of the room.

I'm sure you can get some good advice here, but we'll need the total sq meters of the room. My guess is that you will need two separate units, one on each end of the room. Either two 24btu units or two 18btu units, all depends on the size of the room. The height of the ceiling might be a factor also, so please provide that too.

The rooms are approximately 5 metres by 4 metres, and 5 metres by three metres. There is a cathedral ceiling going up about 5 metres over the entire area, also stairs and a hallway going up to the second floor.

I was hoping that I could get one outside condenser unit that controls two fans at both ends of the room.

It makes sense and can be done in other countries but apparently not here.

Lack of expertise or just trying to sell more?

I re-read your post. So, are the rooms separated by a wall or not? I was thinking after I first replied to your post, if you really wanted only one condenser and one fan blower motor, you can get one larger unit, maybe 38,000 btu, but you would need 3 phase power. Probably not what you want to do. With the room sizes you furnished, two 18,000 btu units, each with fan blowers (inside unit) would most surely be sufficient. You might even be able to get away with 13,000 btu units. But you also thru a curve in to the mix, a cathedral ceiling going in??? How high would that be? And then you also have to consider the cold air flowing up the stairway. So, is it also a two story house? If so, that would cut down somewhat on the size of the a/c units needed, because the down stairs of a two story house is normally much cooler to begin with versus a single story. It sounds more complicated than it really is, but any reliable, knowledgeable a/c/ guy should be able to steer you in the right direction.

I re-read your post. So, are the rooms separated by a wall or not? I was thinking after I first replied to your post, if you really wanted only one condenser and one fan blower motor, you can get one larger unit, maybe 38,000 btu, but you would need 3 phase power. Probably not what you want to do. With the room sizes you furnished, two 18,000 btu units, each with fan blowers (inside unit) would most surely be sufficient. You might even be able to get away with 13,000 btu units. But you also thru a curve in to the mix, a cathedral ceiling going in??? How high would that be? And then you also have to consider the cold air flowing up the stairway. So, is it also a two story house? If so, that would cut down somewhat on the size of the a/c units needed, because the down stairs of a two story house is normally much cooler to begin with versus a single story. It sounds more complicated than it really is, but any reliable, knowledgeable a/c/ guy should be able to steer you in the right direction.

Cold air does not flow up.

Say after me........hot air rises ..hot air rises.....

Yes, Harry you are 1,000 percent correct. BUT, you may not know it, you do loose some cold air from having an open ceiling/stairway - wouldn't YOU agree???