It is impossible to keep a home or office "cool" without a room air conditioner tailored to specific needs. And air conditioners that fit the bill are not necessarily all that "smart." The most efficient room air conditioners are window-mounted, units that can handle everything from the architectural challenge of a custom-built window space to the typical window of, say, a small apartment. Even if the window air conditioning unit is "smart" in terms of features or is remotely operable, it is not going to be half as efficient, or work comfortably, if it is mounted in, say, a bay window, the top half of which does not receive direct sunlight at any time of year, the bottom half of which does, and both halves of which are visible to anyone walking by.
Window air conditioning units are great because they can meet all kinds of diverse cooling needs. For people living in places with high humidity, some units come with even better dehumidifying capabilities to make not just "you" cool, but also "your" space comfortably dry. For those whose main concern is air quality, some models come with filtration systems that would make your allergies or asthma act up way less than they would without an AC. These units are ideal for spaces where you absolutely need to not hear the air conditioner. Some units even have energy-saving settings and are ridiculously efficient, which means they won't make your electricity bills go through the roof while you're trying to stay cool. Whether you need something to cool off a single room or more powerful enough for an open floor plan, there's bound to be a window unit that can do the job.
There are many factors to consider beyond the basic cooling capacity when selecting a window-mounted air conditioning unit. For the installation process, there are many units designed for easy and straightforward DIY installation that can save you the cost of hiring a professional to put it in. Take maintenance into consideration as well. Most modern units are designed with very low upkeep in mind. Many window units, for instance, have filters that can be removed and rinsed clean; even the washing of the filter is designed to take place in a way that save your time.
Still another consideration is space. If you don't happen to have an air conditioning unit with the kind of large profile that kind of unit had in days past, then that might very well be a good thing. In fact, a good number of the window units you'll find these days have a pretty sleek appearance. They don't take up much visual space and can be trusted to perform well as part of the design of the room in which they're installed.