Comparison Deerma DX115C vs Deerma DX700

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.

The nominal volume of the dust collector installed in the vacuum cleaner.

This indicator largely depends on the type of unit (see above). For example, in most handheld household models, the capacity does not exceed 0.5 L. The volume of the container in upright vacuum cleaners and robots can be somewhat larger — among the first variety there are quite a few models for 1 – 2 liters or even more, and among the second — by 0.6 – 1 liter and a little more. For conventional vacuum cleaners, the minimum figure is actually about 0.8 – 1 L; dust collectors for 1 – 2 L and 2 – 4 L are very popular in such devices; the maximum capacity is actually 4 – 6 liters — units of a similar layout, but with a larger capacity, are usually referred to as household ones. In turn, relatively small containers are occasionally found among workshop models. However, in vacuum cleaners of this type, the capacity is generally quite large — it can reach 26 – 50 liters or even more ; the same applies to industrial (construction) units.

In general, a larger dust container allows you to work longer without interruptions. On the other hand, a capacious container itself takes up more space and, accordingly, affects the size, weight and price.... So when choosing this parameter, it is worth considering the actual features of the use of a vacuum cleaner. Here we can give such an example: for a full-scale cleaning of an average city apartment, a capacity of about 1 – 1.5 litres is required. Thus, say, a 4-litre bag allows you to carry out two such cleanings with sufficient efficiency without unloading the vacuum cleaner. There are more detailed recommendations regarding the optimal volume of the dust collector, including specific cleaning options. These recommendations can be found in special sources.

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 leve...l of a loud scream; 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.

The length of the power cord that is equipped with a vacuum cleaner powered by an outlet.

Here we note that manufacturers select the specific length of the cord depending on the general purpose of the unit. In general, the length of 4 – 5 m and less can be called small, 5 – 6 m — medium, 6 – 7 m and 7 – 8 m — more than average, and in some models this figure is more than 8 m. However, a lot depends on the specifics of the vacuum cleaner. For example, among conventional units there are many models with a 4-5 m wire (this is enough for cleaning on the scale of an apartment, a private house or a small office space), but for industrial solutions this is a very limited indicator.

Keep in mind that a longer power cord is not always more convenient. On the one hand, it provides more freedom when working. On the other hand, it can create inconvenience at a short distance from the outlet as well as during storage/transportation. In addition, you can use an extension cord to work away from the outlet. So when choosing, you need to take into account the specific needs of the use of a vacuum cleaner. Detailed recommendations for different situations can be found in special sources.