Comparison HOBOT Legee 688 vs HOBOT Legee 668

The suction force provided by the vacuum cleaner. It is indicated by the maximum vacuum (negative pressure) that the unit can create at the working nozzle.

Note that this parameter is sometimes confused with the suction power described above, which is indicated in watts. Yes, suction force to some extent determines the efficiency of the unit. However, this efficiency also depends on the performance (airflow). And the suction power, indicated in watts, takes into account both of these parameters — it is determined by multiplying the suction force by the performance (see above for more details). For this reason, there is no strict relationship between this force and suction power: for example, a vacuum of 25,000 Pa can be found in models with 250 W, 200 W and even 150 W of power.

As for the practical significance of this spec, in general, a higher suction force allows you to work more efficiently with high resistance. For example, when processing carpets with a long pile. On the other hand, more pascals (with the same number of watts) means less airflow and, accordingly, less efficiency for large amounts of work at low resistance (for example, cleaning large rooms with parquet floors). Thus, it makes sense to pay attention to this indicator mainly in cases where high suction force is fundamental for you. In other cases, it is worth evaluating the capabilities of the vacuum cleaner in terms of suction power in watts.

Note that for a number of...reasons, the suction power is most often specified for robot vacuum cleaners (see “Produc type”). For such models, a value of 1500 Pa and below is considered very small, 1500 – 2000 Pa — medium, 2000 – 2500 Pa — high, more than 2500 Pa — very high.

It is also worth mentioning that the indication of suction force is often used as a publicity trick — to improve the impression of the product. For example, the suction power of 150 watts in itself is quite modest. But at the same time, the suction force of such a vacuum cleaner can be 25,000 Pa — a very impressive figure, especially for an inexperienced buyer, but having a very indirect relation to real efficiency. Especially often, such tricks are used among upright models and the already mentioned robots — these varieties initially do not differ in high power in watts. For many of these units, the characteristics only indicate the vacuum in pascals without specifying the suction power. It further enhances the impression: for example, in the specs of a modest robot, the figure "3000 Pa" looks much more impressive than "40 W". However, such figures have a very weak relation to the real capabilities of the unit and if they are not supplemented by data on suction power in watts, they should be considered solely as bait for a not particularly sophisticated buyer.

Additional modes of operation provided by the robot cleaner (see "Product type").

First of all, let us clarify that the standard modes, in this case, include two formats of cleaning at standard power — continuous, in which the vacuum cleaner carefully cleans the entire room (or its specified area), and chaotic, in which it moves randomly within the working area. Other ways of working are considered additional; their list is given in this paragraph. Among the most common additional modes are spot cleaning (Spot), perimeter cleaning (Edge), and turbo mode. In addition, a fairly popular function is the Zigzag. Here is a detailed description of the different options:

— Spot cleaning (Spot). A mode that allows you to use the vacuum cleaner for targeted cleaning of a relatively small area of the room — for example, when spilling a small amount of debris. Most often, this programme works as follows: the robot moves to the centre of a user-defined zone, and then starts moving from this point in an expanding spiral and stops at a given distance from the starting position.

— Perimeter cleaning (Edge). A mode that allows you to start the vacuum cleaner around the perimeter of a given zone. By the name, it is mainly used for cleaning along the walls of the room: a lot of dirt accumulates in these places, which are difficul...t to remove when using standard cleaning modes.

— Turbo mode. Power mode for more suction force. Usually, the movement of the vacuum cleaner, in this case, can be carried out according to any programme available in the settings — both standard (combing, random movement) and additional (Spot, Edge, Zigzag). Anyway, the turbo mode is useful primarily for cleaning carpets and other floor coverings with pile, for which the standard power of the vacuum cleaner is not enough. However, working at increased traction increases the load on the unit and increases its wear. Therefore, most models have restrictions on the maximum time of continuous operation in turbo mode and sometimes on the minimum duration of breaks between switching on this mode.

— Zigzag. Zigzag movement is a kind of transitional variant between the orderly combing of the room and the random choice of direction. Zigzag allows you to achieve greater efficiency than chaotic movements. In addition, with such a movement, it is easier to compensate for the presence of various obstacles and ensure thorough cleaning of the entire given area.

Additional functions provided in the design of the robot vacuum cleaner (see "Type").

Most often in modern robots you can find such special functions: scheduled cleaning, fall protection, obstacle sensor, object recognition, water supply adjustment, control via the Internet, remote control and video surveillance camera. Here is a more detailed description of each of them:

- Scheduled cleaning. The ability to set a schedule according to which the vacuum cleaner will clean automatically, without additional commands from the customer. At the same time, the specific features of such programming may be different, they should be specified separately. So, in the simplest models, the schedule is limited to individual hours within a day - for example, from 16 to 17; at the set hours, the vacuum cleaner is switched on every day. More advanced devices may provide a schedule for the days of the week or even for the dates of the month or year. In any case, this function greatly simplifies the use: it is enough to set the schedule once - and you can not worry about cleaning for at least a few days; especially since most models with this capability also have the function of docking...(see “Robot Configuration - Charging Station”), and the customer only needs to periodically empty the dust container (which is even more simplified if there is a docking station with a bag - see . below).

- Fall protection. Special protection that prevents the vacuum cleaner from falling off steps, high thresholds, etc. In most cases, the basis of such a system is one or more sensors located on the underside of the case. When the vacuum cleaner travels to the edge of the surface being treated, the sensor reacts to this edge - as a result, the device stops and changes direction in order to avoid falling.

- Obstacle sensor. Sensor (or sensor system) for detecting obstacles in the path of the vacuum cleaner. The specific type of such sensors can be different: ultrasonic, infrared, laser, contact, etc. However, in any case, this function allows the device to move in space, avoiding collisions and determining the best detour path. Note that models without such a sensor, for the most part, are also able to bypass obstacles - however, for this, the robot must not only stumble upon a foreign object, but try to pass through it. And only in case of failure, the trajectory changes - moreover, randomly, far from always in the optimal (or at least suitable) direction.

- Object recognition. The function of recognizing various objects on the floor that may interfere with the cleaning process. It is implemented through the presence of a front camera to adjust the optimal route for the vacuum cleaner along the perimeter of the serviced area. The camera in the design of the robotic cleaner reads the outlines of objects and allows you to bypass such obstacles. As a result, slippers, socks thrown under the bed, children's's toys and wires will no longer interfere with the movements of the vacuum cleaner. The function is of particular benefit in the presence of pets at home that are not accustomed to the tray - the robot will calmly has their waste products and keep the nervous system of pet owners healthy.

— Adjustment of water supply. Dosing system for the degree of wetting of the washing cloth in automatic mode. The ability to select the intensity of the water supply allows you to adjust the operation of the robotic vacuum cleaner for different types of floor coverings. For example, for parquet and laminate, the customer can set a low water flow rate, and for less whimsical tiled flooring, a high water flow rate. Also, the vacuum cleaner can turn off the water supply to avoid leaks, for example, when charging. In advanced models of robotic vacuum cleaners, the function of choosing an individual degree of wetting of the napkin for each of the rooms of the dwelling is often incorporated.

— Docking station with a bag. Docking station with its own trash bag. Upon arrival at such a stand, the robot can not only recharge the battery, but also carry out self-cleaning - unload the collected garbage into an external container; The capacity of the dock, as a rule, is enough for several unloadings. The convenience of this function is obvious: it allows the device to work longer without customer intervention, eliminates the need to manually clean the vacuum cleaner when the dust container is full (besides, unloading garbage from the dock is usually easier than such cleaning). True, and such opportunities are quite expensive.

- Management from the Internet. The ability to control the vacuum cleaner via the Internet - most often through a special application on a smartphone or other gadget (theoretically, such control is also possible through a web page that opens in any browser, but in practice this method is almost never used). The robot itself is connected to the network via Wi-Fi. The main advantage of this function is obvious - it allows you to give commands to the device from anywhere in the world where there is Internet access. In this way, for example, you can start a cleaning programme the day before you return from vacation in order to return to a freshly cleaned apartment. And the vacuum cleaner, in turn, can send various notifications to the customer - about the state of the battery, the progress of cleaning, the fullness of the dust container, etc.

- Remote control. A classic remote control that allows you to give commands to the device from a distance. As a rule, such a remote control covers all the main functions of the vacuum cleaner, and in many models it also allows you to directly control the movement. In any case, without remote access, it would be very difficult to control a moving vacuum cleaner - you would either have to wait until it finishes working, or catch the unit on the go. In light of this, this feature is very popular; however, on sale you can find a lot of robots without a remote control. As a rule, these are either the simplest budget devices with a random movement mode and without any additional functions, or advanced models where a smartphone / tablet with an application is used for control.
We also note that the remote controls in robotic vacuum cleaners usually work via an infrared channel - similar to remote controls for TVs, air conditioners, etc. Thus, to receive a command, the vacuum cleaner must be in the line of sight. However, in most cases this can not be called a serious inconvenience.

- Videcam. Own surveillance camera built right into the vacuum cleaner. This feature is only found on web-based models (see above); it allows you to use the robot as a remote video surveillance system and control the situation in the room, being outside and watching the picture from the camera on the smartphone screen. Also, the built-in camera can be used in the mapping system (see "Building a room map") - however, we note that not every vacuum cleaner with a built-in mapping camera has a video surveillance function.

Types of voice assistants supported by the robot vacuum cleaner.

As the name implies, this function allows you to control the robot using voice commands. However, we emphasize that in this case, we are not talking about the voice recognition system built into the vacuum cleaner but about compatibility with an external device on which the corresponding voice assistant is installed — a smartphone, tablet, smart speaker, etc. Thus, to use voice control, an additional device will inevitably be required; on the other hand, there are no problems with the search for such a device nowadays. And in itself, such a control method often turns out to be more convenient than a command from the remote control or searching for the desired option in the control application.

As for specific assistants, the most popular nowadays are (in alphabetical order) Amazon Alexa, Apple Siri, Google Assistant. And in robot vacuum cleaners, compatibility can be provided both with one of them and with several at once. The specific control functionality available through the voice assistant should be specified separately for each model. It is also worth paying attention to the supported languages: for Siri, the language must be selected in the settings, for the Google Assistant, automatic language recognition is available (some adjustment may be required), and in Alexa (as of early 2021) support for the Russian language is not provided at all.

The rated voltage of the battery used in the vacuum cleaner with the corresponding type of power supply (see above).

Initially, manufacturers select the characteristics of the battery (including voltage) in such a way that the vacuum cleaner can be guaranteed to deliver the power claimed in the specifications. Therefore, when choosing this indicator often does not play a decisive role. However, it can also be useful in such cases — for the most reliable comparison between models with different battery capacities in ampere-hours. See "Battery capacity" for details.

In addition, voltage data can be useful during operation — for example, to find a spare/replacement battery or a third-party charger.

— Ni-Cd (nickel-cadmium). The oldest of the options found in modern vacuum cleaners. It features high reliability, resistance to temperature extremes and good charging speed even with high capacity. The main disadvantage of this type of battery is a memory effect — a decrease in battery capacity if it is charged without being completely discharged. In addition, Ni-Cd batteries are considered environmentally unsafe. However, they are still widely used because of their low cost and decent performance.

— Ni-Mh (nickel-metal hydride). Further development and improvement of the nickel-cadmium batteries described above. While having the same basic advantages, Ni-Mh batteries are not affected by the memory effect and are safer to manufacture. Their disadvantages are the higher cost and somewhat shorter service life compared with the original Ni-Cd technology.

— Li-Ion (lithium-ion). A type of battery originally developed for use in portable devices. However, with the development of Li-Ion technology, it has been applied to other industries. The main advantage of such batteries is their high capacity with small dimensions and weight. It is also worth noting that they are not subject to the memory effect and can charge quite quickly. On the other hand, this option is not without its drawbacks — it is, first of all, sensitive to too low or elevated temperatures and a high price.

— Li-P...ol (lithium polymer). An improved version of the lithium-ion technology described above allows even more compact yet high-capacity batteries. The reverse side of these advantages is higher cost and increased sensitivity to low temperatures. However, for batteries used in vacuum cleaners, the latter is not critical.

The capacity of the battery installed in the vacuum cleaner.

Recall that batteries are used in all robots, as well as other types of vacuum cleaners for which mobility is important; see "Power supply" for details. As for battery capacity, theoretically, a larger battery allows you to work longer without recharging. However, there are nuances. Firstly, the actual battery life of the unit will also depend on its type, power and some features of the functionality. Secondly, the actual battery capacity is determined not only by this indicator but also by the voltage in volts. So if these batteries differ in voltage, you need to convert their capacity into watt-hours and use this data when comparing. These calculations are described in more detail in special sources.

In light of all this, only vacuum cleaners with similar specifications can be directly compared in terms of battery capacity. And it is best to evaluate the actual battery life by the directly claimed operating time.

The noise level produced by the vacuum cleaner during operation. Usually, the value for normal operation at maximum engine power is indicated here. With less power, the loudness of the unit may be lower, but the key is precisely the maximum indicator.

Regarding specific numbers, keep in mind that the decibel used to measure the noise level is a non-linear quantity. Therefore, it is worth evaluating specific indicators using special comparative tables. In general, vacuum cleaners are quite noisy appliances; so in this case, models are considered quiet if this indicator does not exceed 65 dB — this is the level of a loud conversation between 2 – 3 people at a distance of 1 m. The quietest of these models give out only 40 dB — this is the average volume of a person’s speech in normal tones (and the minimum volume allowed for constant noise sources in living quarters during the day). For louder units, the comparison table looks like this:

— 66 – 70 dB — loud conversations between several groups of people at a distance of about 1 m;
— 71 – 75 dB — the volume of a cry or laughter in full voice at a distance of about 1 m;
— 76 – 80 dB — the volume of a mechanical alarm clock or the engine of an old truck;
— more than 80 dB — a very high noise level, exceeding the level of a loud scr...eam; when working with a vacuum cleaner having such specifications for a long time, it is highly desirable to use hearing protection.

Also note that the noise level largely depends on the engine power, as well as some other features (for example, it is strongly affected by the presence of an aquafilter — see "Dust collector"). At the same time, there is no hard connection here, and units with a similar set of specifications can differ markedly in actual loudness. In such cases, when choosing here, it is worth proceeding from the fact that a quieter vacuum cleaner will be more comfortable to use. However, it will most likely cost noticeably more.