Ventilation pipes for a kitchen hood: types, installation

An extractor hood in the kitchen is needed to remove fumes, smoke, harmful combustion products and odors during cooking. An air duct connects the hood to the ventilation duct. To provide ventilation, it’s not enough just to buy a good range hood. It is necessary to choose the right exhaust pipe. In order not to be mistaken, you should learn about the differences between different types, take into account the features of operation, installation and much more.

Plastic pipes for cooker hoods

Material. PVC

Diameter. In the cross section, the pipe is round and rectangular. The latter is also called flat. The most popular diameters: 100, 125, 150, 200 mm. As for the rectangular ones, the following sizes are most in demand: 55-60 mm per 110-204 mm.

Resistance. The plastic is smooth, so the air duct of this material has a low resistance to air flow. If we compare the round with the rectangular, then the first air will move a little faster.

Exploitation. The working temperature of the plastic is up to +70. It is not susceptible to corrosion and does not require cleaning: grease and dirt do not adhere to a smooth surface.

Noise level. The plastic duct is smooth inside, there is nothing to cling to the flow, so the ventilation is silent.

Assembly. Installation is simple, but connecting with adapters takes time. Too complicated configuration of kitchen furniture and walls plastic duct «repeat» cannot: sharp and frequent bends impair ventilation.

Cost. Low, but the cost increases adapters, without which you can not do.

Appearance. PVC pipe in the kitchen looks aesthetically pleasing. This is especially true for one that has a rectangular section. In addition, the plastic can be painted in a suitable color.

Metal pipe

Material. Speaking of a metal duct, most often they mean aluminum corrugation. This flexible pipe can also be plastic, but because of its cheapness, aluminum is the most widely used. It is made of multilayer foil folded accordion. It has a frame inside - rings made of steel wire.

Diameter. The cross section of the corrugation is only round. The diameters most in demand are: 100, 120, 125, 150 mm.

Resistance. Although the corrugation is stretched at the time of installation, the grooves still hold the air a little. On a smooth surface, it moves faster.

Exploitation. Operating temperature - +300 and above. Corrugation is resistant to corrosion, but requires periodic cleaning. Fat, soot sticks to the ribbed inner surface.

Noise level. Air «clings» for the rings inside the pipe. This makes her vibrate, creating a noise. Therefore, the metal duct works louder than the plastic one.

Assembly. Installation takes place very quickly: it is simply stretched over long distances. A flexible sleeve is able to extend 4.5 times. It is easy to turn the duct in any direction, which means that L-shaped adapters are not needed. Corrugation «adjusts» under any configuration of furniture and ledges on the walls.

Cost. Cheaper than plastic, plus savings on adapters.

Appearance. A flexible metal duct is not as beautiful as a plastic one.

Air outlet options

With two inputs

Not a very common option. When there are two separate openings in the exhaust duct in the wall, everything is simple. A pipe is brought out into one, and the other remains for natural ventilation. However, during operation of the exhaust hood, a nuisance may arise - reverse traction. Proper ventilation suddenly begins to work in the opposite direction, filling the kitchen with unpleasant odors. Consider why this happens and what to do.

If there is no hood in the house, but only a ventilation duct, the air should still change. This is how natural ventilation works. Warm indoor air is less dense than cold outdoor air. Less dense means light. He rises and goes into the ventilation shaft.

From the cracks in the windows and doors in the kitchen should come fresh air. When designing houses, it was assumed that this is how ventilation will be carried out. Today, almost everyone has sealed plastic windows and doors with gaskets that violate the principles of ventilation. Ideally, if the double-glazed windows do not provide air flow, the situation should be corrected by supply valves. They are installed in a plastic window or wall next to them.

If you install a cooker hood, the situation will be complicated. Modern hoods are very powerful. During their work, all the air from a small kitchen is taken very quickly. Suppose in an hour she «took» 1000 cubic meters of air. Tightly closed windows do not let in air from the street. Then the ventilation starts supplying the kitchen with exhausted, unpleasant smelling air.

To prevent back draft, when turning on the hood, open the windows or install a check valve in the second ventilation hole. When it is turned off, the valve will close without passing dirty air into the kitchen.

Single entry

Most often, the kitchen wall has only one window into the ventilation. Above we talked about the features of different pipes for the hood to the kitchen. This, the most common option, was meant.

If the ventilation hole is one, in no case do not need to completely cover it with an air duct. Many people think: since there is a cooker hood, it means that the ventilation is of high quality. In fact, an exhaust hood is not mentioned in regulatory documents. Ventilation ducts, by contrast, are required when designing buildings. If the hood with its air duct blocks the entrance to the ventilation shaft, then ventilation in the kitchen is impossible.

No matter how powerful the exhaust umbrella is, it is not able to suck in air that is far away, for example, under the ceiling or against the opposite wall. To remove the air mass at a distance greater than its inlet, the hood is not under force. So she «works» only with air above the stove. The rest should go through the exhaust duct.

The best solution is to install a special grille on the ventilation hole. It differs from the usual one in that it consists of two parts: openings for the duct and grilles for natural ventilation. In addition, a check valve is needed.

Outside

Unfortunately, the dimensions of the entrance to the ventilation shaft are often modest: 130 x 130 mm. If you give most of the hole under the duct, there will be very little space for natural ventilation. Therefore, the ideal option is to bring the exhaust pipe to the street, and leave the window in the ventilation duct with the usual grille.

You cannot cope with this work on your own - you need to invite specialists. They will make a hole in the wall with a diamond drill, install a pipe and a protective deflector. This is a device that enhances traction and protects the duct from precipitation, the formation of an ice crust. The deflector also has a valve that closes and does not let in cold air.

Rule for all types of pipes

It sounds like this: the longer the duct, the more bends in it, the lower the performance of the hood. With each additional meter it works 5-10% worse. Each turn slows the air flow.

If the gas stove is rigidly fixed and the window into the ventilation duct is located nearby - excellent. If at a great distance - there's nothing to be done. It is advisable to move the gas stove on a flexible hose or electric one closer to the ventilation duct. It is good when the arrangement of kitchen furniture allows you to do this. The worst case scenario is when the ventilation duct and the hood are located on opposite walls. It is desirable that the ventilation pipe does not exceed 3 m.

Buying a vent pipe. What length, diameter and shape?

A pipe is bought after acquiring a hood and after deciding where to take it.

• Length. Both plastic ducts and corrugations come in different lengths, so picking up the right one is easy. If the pipe is long, it is shortened: plastic - with a hacksaw, and the corrugation - with scissors. To build up metal, use aluminum reinforced adhesive tape.
• Diameter. The hood instructions indicate what diameter the duct should have. If plastic pipes of the required diameter are not on sale, then adapters are used for connection. But it is worth remembering: when its diameter is larger than the diameter of the exhaust pipe, the load on the motor increases. If the corrugation is slightly wider, it is simply pulled together with a collar.
• The form. The pipe may not coincide with the opening of the exhaust hood or with the opening of the ventilation grill in shape. Then use adapters with round to square shape.

Plastic duct installation

Speaking of installation, we will bear in mind precisely the most common way to output an air duct - to an exhaust duct with one entrance.

To assemble a plastic pipe, adapters are needed. In a general sense, adapters are called elements for connecting in a straight line (without a turn), at right angles, for connecting an air duct with an exhaust hood and with a ventilation grill. When connecting, the joints must be insulated so that the exhaust air does not pass into the kitchen.

On the ventilation duct, a grill is installed for natural and forced ventilation. It is a two-piece plate. At the top there is a round hole in the entrance to the ventilation shaft with a flange, and at the bottom there is a grill. If the diameter of the duct does not coincide with the diameter of the flange, or if the pipe is rectangular, and the flange has a circular cross section, adapters are used in such situations.

Installation of a round corrugation

Adapters are not needed to assemble flexible ventilation, because the corrugation bends and rotates at any angle. The corrugation is put on the exhaust pipe and tightened with a clamp. Then stretch as much as possible so that over time it does not sag. The other end is inserted into the flange of the ventilation grill, fixed with a clamp. The ends of the corrugations are not sealed for two reasons. Firstly, because the flexible pipe needs to be cleaned from time to time inside. Secondly, because it vibrates during operation, which may cause cracks. Throughout the corrugation, every 1-1.5 m, it is fixed on the clamps so that it does not swing.

How to hide the duct

Ventilation can look very bulky and ruin the kitchen. To make the pipe less noticeable, it is usually laid over kitchen cabinets or under the ceiling. If the duct is plastic, the simplest thing you can do is paint it to match the walls or furniture. All these are half measures. To hide it from strangers, you will need materials and time.

• If the ventilation does not pass through the entire wall, it can be hidden in a wall cabinet by drilling holes. It is good when the entrance to the ventilation duct is directly above the hood. It is convenient to hide such a direct duct in a decorative box made of metal to the color of the hood or plastic.
• When the pipe is very long, you can make a box of moisture-proof drywall under the ceiling. And to justify its presence, decorate with decorative lamps.
• If ventilation is installed during the repair, then you can hide the duct in the construction of a multilevel ceiling - suspended or suspended.

Now, understanding the features of the ventilation pipes for the kitchen, you can choose the air duct to fit your requirements. Knowing the nuances of installation, you can assemble it yourself. Understanding how to properly withdraw it, you can provide good ventilation in the kitchen.

Video: decorative exhaust duct for ventilation of the kitchen