Do you think 3-in-1(Air-conditioner+heater+humidifier) will be wanted?

well in central saudi (riyadh) a humidifier might be helpful during winter time. and a dehumidifier is not that required even on the coastal areas. the whole thing that you need to study is the due point of Saudi Arabia which is pretty tricky since the country is covered with water on the 3 sides.

at night it's cold there, right? wikipedia said it's about 0-10'c.
people in Saudi Arabia don't use heater?

It could be preferred by some people, but not by the most...Only if you can make the price close to the ones has one function ...then you will win a good share..

heeelooo this is saudi, women cant make a real business here, anyway most accomodation has ac and heating, think of another idea, and also have you looked into shipping anything into this country? I live on a beach compound, in the summer everyone is inside with ac no need for dehumidifyers.............try Singapore!

mynameisna wrote:

at night it's cold there, right? wikipedia said it's about 0-10'c.
people in Saudi Arabia don't use heater?

Wikipedia can say a lot of things that can and need not be true.

Saudi Arabia is a desert in the tropics, and hence hot most times of the year. Summers brink at 45-50C winters are mild with the lowest being 0 or (-1), On the coasts, humidity is very high during the summer months and can be as high as 85 and even higher. The central region has dry summers and that is where the humidifier will be useful. The nights in summer are really hot as well, with temps from about 35+ to nearly 40s.

most people I know of who live in Dammam or Jeddah, the two coastal cities on the east and west resp. use A/cs for around 9 months of the year. From mid-November to mid Feb is the only time when most of the A/c units are switched off. and at least on the coasts, there is no much requirement for heaters. Humidifiers are not used in these parts. In then Riyadh which is in the middle of the desert, people have air-conditioning units as well as desert coolers, desert coolers give the necessary humidity  while a/cs to really bring down the temp some.

I hope that this gives you some idea now on the ground realities.