Usually, the first thing people take into consideration when choosing a cordless handheld vacuum is the way it looks. Before paying for a hand vacuum, customers spend some time experimenting with the models displayed at the store, picking each one up to make sure the handle is in the right place and the product as a whole is ergonomic. What the customers are even more interested in is the mouth part of the vacuum and whether it has a brush to collect dirt. They also like it if the unit is shaped to fit the corners so that it can clean those difficult spots.
The shape and design of a product is a plus, of course. However, there are far more important features you need to look for if you want a good handheld vacuum that will let you down when you need its service. The most important piece of data you want to know about your prospective vacuum cleaner and what the manufacturers are least willing to tell you is the suction power. Conventional corded vacuums that take energy from an electric socket are rated based on their kW power, that is the amount of electric energy they consume every second. Buying battery powered vacuums is a different story. They could also have a kW rating but for some reason, there seems to be a consensus in the appliances industry that cordless appliances should not get a kW rating. That is why we are left with cubic feet per second or cfm when it comes to cordless handheld vacuums. As anyone with some physics knowledge would have guessed, cfm tells the volume of air sucked every second by the unit and this is really an objective and useful gauge of a cordless vacuum cleaner's performance.
If a handheld vacuum has ridiculously low cfm rating, its smooth and ergonomic design is going to do little good. Interestingly, for some cordless products in the market, no data is available on the suction. With no objective information about the performance of a vacuum, purchasing it is a risky choice. That is why you should search for the cfm data on each cordless handheld vacuum and then compare them to get the one the right one.