The sound of a working hood can be loud, more than 45 dB. At this noise level, it’s hard to fall asleep or do normal activities. To reduce the noise of the hood in the kitchen, sometimes it is enough to insulate the air duct, pay more attention to the selection and installation of the device.
Noise levels
The noise of the device depends on its power. A more productive device works louder. The noise level of the hood for the kitchen: 50-60 dB at maximum speed. 50 dB is produced by a device with a capacity of 500 m3 / h, 60 dB - 600-1000 m3 / h. For comparison, the level of sound intensity:
- whisper - 20 dB;
- quiet speech - 30–40 dB;
- loud speech - 60–70 dB;
- the drone of a passing car is 70–80 dB.
With prolonged noise above 80 dB, a headache appears, irritability, hearing deteriorates.
Manufacturers will improve models, trying to reduce the sound volume. On sale you can find hoods with a maximum noise level of 35 dB.
The main factors affecting the exhaust hood noise
There are no completely silent exhaust devices, because they work due to the motor. In some devices, not one, but two engines are installed.
The noise level is influenced by several factors:
- Performance. A more powerful motor absorbs air faster, so it makes noise as it passes through the duct.
- The volume of the kitchen. Power must be selected in accordance with the volume of the kitchen, if it turns out to be too large, the appliance will noticeably make noise.
- The diameter of the duct. According to the laws of physics, the same volume of air passes through a channel with a smaller cross section at a higher speed. The movement of the air stream causes extraneous sounds: the higher the speed, the louder the hum.
- The number of bends and transitions to the ventilation shaft. Obstacles on the way contribute to the appearance of extraneous noise. Bends at right or acute angles, transitions from one material to another, from rectangular to round, or vice versa, from large to small diameters, or vice versa - all these are reasons for the increase in noise.
- Duct material. When choosing a material for manufacturing a ventilation duct, you need to remember the rule: the smoother its walls, the less noise the hood will emit during operation. If the duct does not need to be bent, smooth plastic rather than corrugation is preferable. If you want to lay the track at a right angle, the corrugation is better, because it has a flexible, rounded body.
- Build quality. Poorly fixed parts vibrate during operation and therefore make noise. Its level depends on the quality of the assembly and the quality of fastening to the wall of the device and the duct.
Sound intensity depends on the specific model and is determined by the manufacturer: the parameters are indicated in the technical passport.
What could be the noise
If the cooker hood is very noisy, you need to determine if the noise is a result of a breakdown. If the hood used to work quietly, and then began to buzz, it most likely broke. The malfunction is indicated by a hum, which increases with time, as well as vibration, rattling, arising due to backlash or broken off fragments inside the case.
Sound character:
- rattling and vibration - a sign of backlash of the exhaust mechanism, housing or duct;
- rumble of a fan - breakage or contamination of the blades;
- a whistle in the duct - leaks;
- buzzing in the duct - narrow section, high air speed, the presence of adapters and turns;
- engine noise - a powerful motor operating at maximum speed, or a sign of failure.
To make the hood in the kitchen quieter, you need to repair it yourself or consult a specialist.
Hood noise reduction
There are two ways to reduce hood noise. The first is to carefully calculate the characteristics of the device in accordance with the volume of the kitchen, the distance to the ventilation shaft, and the height of the installation. The second - in compliance with the rules for installation and verification of fastening of all elements.
Usually, inexpensive devices that are made of low-quality materials and assembled with errors make noise. If the hood is above average, the build quality is better and they make less noise at the same power.
The performance of the device is selected taking into account the area of the kitchen, but at the same time with a small margin, so as not to include the hood at full power. Then the noise level will be acceptable. Formula for calculating optimal performance: Skuh× Hsweat×12×1,3; Where Skuh - area of the kitchen, Hsweat - ceiling height.
The diameter of the duct must correspond to the exhaust power. The recommendations are presented in the table:
| Extraction rate, m3 / h | Section mm |
| 150-200 | 100 |
| 200-1000 | 150 |
| >1000 | >200 |
To make the cooker hood more quiet, the cabinet in which it is built in is pasted over with sound-absorbing materials, and the duct is soundproofed. There are special noise absorbers for ventilation ducts that look like separate fragments of it. They are made of soundproof materials and are installed in the gap channel. As a result, the sound waves are suppressed, at the same time there is no unnecessary load on the air duct, and an obstacle to the air flow is not created.
Try to make as few turns and transitions as possible or not to do them at all. The right angle, if you can not do without it, is rounded or broken into 2 angles at 45 degrees.
When installing the duct use screeds and clamps, sealant. The hood is fixed tightly so that there is no play. Even a small gap between the wall and the appliance causes vibration and noise. If there are abnormal sounds, the fasteners must be checked and tightened.
Observe the working height of the installation: for an electric stove - 60 cm, for a gas stove - 75–80 cm. If the distance is greater than the recommended one, the extraction power must be increased, otherwise it will not perform its function properly. If you install it below, the plastic parts will melt, and they will also make noise.
DIY soundproofing
You can soundproof the entire duct using rolled materials. The noise isolator is selected depending on the place where it will be installed:
- mineral wool - for steel duct;
- polymeric materials such as foamed polyethylene, polyurethane foam - for ventilation;
- organic sound insulators - for furniture where the hood is built in.
Installation is carried out using its own adhesive layer of material, using glue or by wire, clamps. In addition to installing sound insulation, it is recommended:
- install vibration dampers or springs under the fans, this will reduce the noise of the exhaust fan;
- replace a rectangular duct with a round one.
Special sound absorbers are inserted into the duct as a sleeve or adapter. At the same time, it is no longer necessary to glue other parts of the duct with sound insulation. This is one of the most convenient and rational methods of sound insulation.
Rules for reliable operation of the hood
If the noise is not a feature of a particular model, it occurs due to non-compliance with the operating rules and a malfunction of the device.To repair the hood did not have to often, you must:
- monitor the cleanliness of filters and hoods;
- do not leave the stove turned on without dishes;
- touch the hood only with clean hands;
- to be careful.
Dirt and grease accumulated on the fan blades or the filter increase the noise: the fan vibrates and the filter does not let air through, so you have to choose a more powerful mode. Pollution that gets into the duct taps, picked up by a stream of air. It is necessary to periodically clean the hood, and if necessary, the duct.
If the hood in the kitchen is noisy, you first need to find out the cause of the loud sound. The broken device is repaired, the vibrating elements are fixed. At home, it is advisable to do some work yourself. For example, installation of sound insulation does not require special skills.
