Proper Selection Of Mini-Split System For House In Mexico

[flybeech]

I have a new, little house in Merida Yucatan Mexico that I would like to have a split-system installed in. Before selecting an installation and a contractor, I want to educate myself first, because I have many unfamiliar variables that will affect what I choose.

The biggest factor is the way Comisión Federal de Electricidad (CFE or just "The Commission") charges for electricity. I cannot AVERAGE more than 850kWh usage per month, or the commission will rate me as the dreaded DAC (De Alto Consumo) and pay many, many times more per kWh. Electricity is very cheap in Mexico, but for the DAC, electricity skyrockets to well over $250 per 1000kWh per month.

The house is of 8-inch solid concrete construction for the walls and roof, without any insulation. There are maybe 10+% single-glazed windows. In other words, insulation is non-existent in Mexican construction. I have included links to the floor plan and the temperature chart of Merida Yucatan, below.

The house is 780sf. The two bedrooms are 155sf, the living room is 202sf, the dining room is 122sf, the kitchen is 75sf and the bathroom is a whopping 33sf. The average low temperature of Merida is between 50F - 75F and the average highs are between 82 - 100F with significant humidity.

I thought about a system with three evaporators, one in each bedroom and one in the kitchen with a system rating of 12 to 18,000btu. It appears that a condensing unit with a SEER of over 16 and an inverter on the compressor would be worth the extra cost.

I have no idea how to properly calculate my needs and I think the local contractors do little more than guess. As close as the numbers are, good calculations are critical. Would anyone here be able to help me calculate what I would need and make recommendations for an appropriate system? Is it even possible to air condition the whole house without exceeding my 850kWh monthly usage?

Floor Plan http://i167.photobucket.com/albums/u...cas/pag5-1.jpg

Merida Yucatan Mexico Average Temperature Chart: http://i167.photobucket.com/albums/u...emperature.jpg

[REP]

I have no idea what Mexico calls elec service.Is it 100v or 120v or 150v ,I have no idea.Is it 50 or 60 hz?
Then it might be wise to walk around a bit and see what brands are in common use.There is no sense in getting a high effiency unit if the locals can't get service parts for it.

[Random Guy]

I think Mexico uses a system similar to the United States for their electricity. As for sizing your mini splits, a Manual J would be the way to do that. There should be a link somewhere on this site to download some software that will allow you to do that yourself for about $50.

[flybeech]

I have no idea what Mexico calls elec service.Is it 100v or 120v or 150v ,I have no idea.Is it 50 or 60 hz?
Then it might be wise to walk around a bit and see what brands are in common use.There is no sense in getting a high effiency unit if the locals can't get service parts for it.

Mexico has the same electrical standard as the US. In my house, that would be 230VAC at 60hz. Also, the split AC's pretty much the same selection as we have here in the US.