Humidity question

[Elialit]

Hi guys!
I have a friend from Japan who asked me for help so I'm here.
The climate in Japan in winter is pretty dry. So my friend complained that his orchids this winter feel bad. He thinks it's because of the dry air in his flat. There could be many factors but I agree that he should maintain the humidity level of at least 35%. We have come to the conclusion that he needs to buy a humidifier for the room with orchids (at this forum also discussed this question Orchids:Best Humidifier for Orchids?).
I'm not an expert in humidifiers because in my city the humidity level is high all the time. So if you use a humidifier - which one (warm misters/cool misters)? And is it necessary at all? Maybe there could be other options.

P.S. he grows phalaenopsis, dendrobium, oncidium, miltonia (if this info could help).

[Ray]

35% is probably adequate, but I really think 50% is better - for the plants, the individual and the structure.

Humidity is humidity no matter what the source. “Cool mist” types tend to be more energy efficient than warm mist ones, but the minerals dissolved in the water end up becoming deposited as a fine dust throughout the house.

Capacity is more important than type, and console type “whole house” humidifiers that blow air through wicking material saturated by capillary action might be the best.

Read this and this.