Max. air flow rate
The highest speed of the air stream given out by the vacuum cleaner. The
higher this parameter, the stronger the thrust provided by the device, and the more efficiently it is able to pull or blow out debris particles from cracks and other hard-to-reach places (of course, if there is an appropriate operating mode — see above). At the same time, in most modern models, this figure exceeds 150 km/h — this is more than enough for work of small and medium complexity. Therefore, paying attention to a high flow rate makes sense only when choosing a powerful model for working in difficult conditions; we note that in the most “high-speed” vacuum cleaners, the indicators can exceed 400 km/h.
Air flow (blowing)
Performance of the garden vacuum cleaner when blowing (see "Operating mode").
This parameter determines the amount of air that the device distills through itself in a certain time. It should be noted that it depends not only on the speed of this air, but also on other parameters — for example, the diameter of the pipe. Therefore, two models with the same performance can noticeably differ in speed, and vice versa. You also need to keep in mind that the efficiency of "purging" bottlenecks with stuck debris does not depend on performance, but on the flow rate. On the other hand, good performance makes it easier to work on large areas, as allows you to simultaneously cover a large area with a jet of air.
Most modern garden vacuum cleaners in blowing mode provide up to 15 m / min;
higher rates are typical mainly for professional models.
Noise level
The noise level generated by the vacuum cleaner during normal operation. The lower this indicator, the more comfortable it is to work with the unit, the less the operator gets tired; and high noise levels may require the use of protection (e.g. earmuffs).
When assessing the noise level, note that the decibel used to measure this level is a non-linear quantity. Therefore, it is easiest to evaluate specific values using comparative tables. Here is one of the variants of such a table (rather simplified):
— 60 dB — sound comparable to a TV at medium volume. From this value, the indicators of modern garden vacuum cleaners begin, because. this technique works quite loudly.
— 70 dB — to a truck at a distance of about 8 m;
— 80 dB — traffic noise on a busy street;
— 90 dB — freight train noise at a distance of 8 – 10 m;
— 100 dB — the noise of the demolition hammer;
— 110 dB — indoor rock concert
