The best fans are capable of making a hot and sticky day far more bearable. Providing you with a breeze of fresh air in your home at a time when even opening the windows doesn't seem to be clearing things up, pretty much every home could do with a fan, especially if you don't have air conditioning. (Though, if you find yourself getting really hot, you might need a portable air conditioner instead of or in addition to a fan.)

A fan isn't as straightforward to purchase as you would think. You need to consider if you want a bladeless design, a particularly quiet fan, one that is tower length or fits in the window, as well as if power or good looks are most important to you.

Like with any purchase, it's also possible to spend a little or a lot on a fan — which is where we come in. To help you figure out where to begin, we've taken a look at all the best fans currently available. We're also on hand to answer some key questions about what you may need to consider before hitting the buy button.

Fans can feel like magic at times, but there's a logic to how they work, even if it sounds a little weird. That's because most electric fans actually add heat to the room as expected of any electrical item. However, they create a wind-chill effect rather than actually cooling the room down. We all lose that through conduction, radiation, convection, and evaporation with the latter two being how fans work at their best.

On any hot day, we sweat to lose heat. Blowing air around, a fan makes it more effective for the air to evaporate sweat on our skin. It might feel like it reduces the temperature but it merely makes us and the air around us feel cooler rather than be cooler in reality.

The faster the fan is, the more it displaces the warmer air that is in direct contact with our skin, thereby improving the rate of convective heat transfer. A steady breeze from a fan is capable of carrying hot air away from you rather than leaving it to feel uncomfortable.

Fans are more effective in some types of heat than others. For instance, when air reaches above 35 degrees Celsius (or about 90 degrees Fahrenheit), you won't lose heat via convection but a fan will help your sweat evaporate faster. A humid heatwave is when a fan is most effective at reducing core temperatures, while a dry heat needs water more so than air.

There's much debate on whether your fan should face in or out of a window too. You should place outward-facing fans on the warmer side of your home to blow the warm air out, while using inward-facing fans to draw cool air into the cooler side of your house. Upstairs in the home is likely to be warmer than downstairs, so you need to plan accordingly.

When it comes to window fans, they work best at dealing with hot air from your home, so you should use these when indoors is hotter than outside. When outside is higher, close your windows and shades to keep hot air from coming in. Closing your windows may sound illogical but it works.

There are a lot of different fans out there. They all perform very similar tasks with the main difference being how they look. Ceiling fans are popular amongst people who wish to mount a fan out of the way. Then there are table fans for placing on a counter or unit, along with tower fans for setting upright next to other furniture. Pedestal fans are as similarly independent as tower fans but with a different look, as are floor fans.

There are also exhaust fans and wall-mounted fans, but we've mostly focused on ones that involve the least amount of installation.

Not everyone wants a quiet fan. This is one choice that's highly personal. The noise doesn't affect how well a fan operates but you may find yourself preferring one to the other. Some people enjoy the noise that a fan makes, treating it like white noise to zone out to. Others may find that a noisy fan is irritating and disrupts their sleep or rest. There's no one-size-fits-all solution here.

A fan's power is measured by the airflow it generates in cubic feet per minute. Referred to as CFM, the higher the rating, the more powerful the airflow.

Most fans offer more than one fan speed so it's possible to choose a setting that works well for your situation. Sometimes, you may want a more gentle breeze than other times.

It's even possible to determine what CFM you need. You'll need to know the size in cubic feet of the room you're cooling. From there, you can divide the cubic feet by the CFM rating of a fan. The result tells you how many minutes it takes for the fan to change the air in the room. The lower the number, the more effective it will be at cooling your space.

Some guidelines suggest you may want a fan that can recirculate the air between 5 and 6 times an hour for a bedroom or slightly more for a kitchen.

Another way of checking power is to see what motor is used. A DC (or direct current) motor is more energy efficient because it uses less power, but an AC (alternating current) will provide you with the most power. Some fans also refer to their velocity rather than CFM.

The features you need when buying a fan will differ on why you need one. One thing that's likely to remain important for everyone is fan power. If you're looking to cool down, you need a fan with a high CFM rating to ensure superior airflow. It's also useful to consider if you need one that has blades or a bladeless design. The latter is particularly useful if you have young children who may try to get too close to a fan's blades. Automatic oscillation is a good idea as well, because it means the fan moves from side to side automatically, widening its coverage and keeping hot air at bay.

From there though, things can vary depending on your needs. For some users, variable speeds are essential with different speeds useful for managing cold air. For others, being able to use a remote to manipulate the fan is convenient if you don't want to be physically near the fan at all times. Being able to adjust the height or fan head can prove useful but isn't always vital. Similarly, some high-end fans provide more than just good air circulation — they also include air purifying features. Finally, consider what design fan you need. This can range from a pedestal fan, box fan, standing fan, floor fan, table fan, or much more.