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In order for the apartment or house to have fresh and clean air, the kitchen must have very good ventilation. Natural ventilation cannot cope with the task of timely removal of odors during cooking, therefore a special forced ventilation device, a kitchen hood, is hung over the stove. How to install the hood correctly, how to fix it and bring it into the ventilation system – more on that later.
How to hang a hood over the stove
With the right size, it is equal in width to or even slightly larger than the width of the plate. To properly install the hood, it must be correctly positioned and fixed. The electric hood is located exactly above the stove. The installation height depends on the type of hob:
- Above the gas stove, the minimum allowable height for hanging the hood is 75 cm.
- Above the electrical value is slightly less – 65 cm minimum.
You determine the exact height yourself – according to the height of the hostess who will cook. The bottom edge of the hood should be just above her head. You should not hang lower than the minimum distance, but you can hang higher. But if you need to hang the equipment higher than 90 cm from the level of the stove, you need a unit with increased power – so that polluted air is removed efficiently.
The hood is attached depending on the type. Built-in – to a cabinet specially ordered in size. Hinged (flat) and domed (chimney) – to the wall. Chimney hoods themselves can consist of two parts – a unit with a motor and filters and a dome. Both parts are attached independently of each other, but so that their outputs coincide.
Separately, it should be said about island hoods. They are attached to the ceiling. The kit comes with a suspension system and clear recommendations on what and how to do.
Installation steps
The entire installation and connection process can be divided into several stages:
- First you need to install the hood in the right place. This involves physically attaching it to a wall or ceiling.
- The second step is connecting to the power supply. If there is an outlet nearby, there should be no difficulties. Otherwise, you will have to pull the wire from the nearest source; as a temporary measure, you can use a carrying (extension cord).
- The last stage is relevant only for models with exhaust air outlet to the ventilation system. At this stage, the duct is connected and output to the ventilation duct.
It is easy to hang the hood in the kitchen with your own hands
If there is a power outlet nearby, there will be no problems with connecting to electricity. Other stages are also not very complicated, but we will consider them in more detail.
Mounting to the wall of a hinged or domed model
Although outwardly these two models differ, they are attached to the wall. They have four holes on the back wall of the case – two on the left, two on the right. Many manufacturers supply their products with a mounting template, which marks the location of the fasteners. All that is needed is to lean the template against the wall, transfer the marks. If there is no template, measure the distance between the holes, transfer to the wall. If there is an assistant, you can ask to hold it at the chosen height, and make marks yourself.
Then everything is simple: using a drill, we make holes of a suitable size, insert the plastic plugs of the dowels, then hang the hood on the dowel-nails. Naturally, we check the horizontalness of the installed equipment.
This method is good if the wall is even and nothing interferes. Often a gas pipe runs next to the stove, which makes it impossible to hang the hood close to the wall. In this case, wooden bars can be nailed to the wall, and the hood can already be attached to the bars. This is a simple option, but not very good – the bars are covered with soot and it is difficult to wash them.
The second option to install the hood behind the pipes is to use a stud screw (the second name is a plumbing stud). They have a thread for screwing into the wall, a smooth part, which makes it possible to carry the hood to a certain distance from the wall, and a finer thread with two nuts, with which we will fix the body. There are these studs in different sizes, choose which one you need, but all nuts are made to fit a bit or an octagonal key.
This option for mounting the hood is universal, simple in execution, and reliable. It is also more convenient to maintain – the metal is usually stainless, it is not difficult to wash it from deposits.
Installation of a built-in hood in a cabinet
The built-in hood is almost completely hidden in a cabinet made for it. It is fastened in the same way as described above – on screws, only they are screwed into the walls. Only previously in the shelves located above it is necessary to make holes for the air duct. This is done after the hood is purchased, since the location of the air outlet depends on the company and model.
If the locker is hanging, it is better to remove it. In the removed cabinet, install the hood in place, mark the location of the air outlet on the lower shelf, cut it out. To do this, it is easier to use an electric jigsaw and a file with fine teeth. The saw blade for laminate leaves almost no chips. If desired, the cut point can be sealed with a plastic C-shaped furniture profile. They are rigid and flexible. It is easy to use flexible – it bends at any angle, rigid ones will have to be heated with a building hair dryer before installation. These profiles are “sit down” on glue, most often they use “liquid nails”. After installation in place, remove the remnants of glue (with a damp clean cloth), fix with masking tape to the shelf. We cut off the excess profile with a file with a fine tooth, clean the cut with fine-grained sandpaper.
In the same way, we make holes in other shelves. By the way, they may no longer be round, but rectangular – it depends on the section of the air duct you have chosen.
After that, all the shelves are installed in place, the cabinet is hung and fixed. A built-in hood is attached to it with screws through the holes in the case. Next is the process of connecting the duct.
How to connect the hood to electricity
Since the power consumption of kitchen hoods rarely exceeds 1 kW, they can be connected to ordinary sockets. It is desirable that they be grounded. This requirement must be met if you want the warranty to be valid.
If the wiring in the apartment is old, you can throw the ground or ground wire yourself. Just do not attach it to plumbing or heating pipes. This threatens the possibility of electrical injury or even death for you, members of your sichs or neighbors.
To reach the ground wire, on the shield, find a busbar with wires attached to it or a pipe to which a stranded wire is welded / screwed. You can also connect your own stranded wire to these devices (without discarding those that already exist). For it to work normally, the cross section must be 2,5 mm, the conductor is stranded copper, a non-combustible sheath is desirable.
Some of the hoods come with a plug at the end. With the connection of such models, there are no questions – to the outlet and that’s it. But there are models in which the cord ends with wires. This is not from the greed of the manufacturer, but for the consumer to decide for himself how best to connect the equipment. If you want, you can connect the plug. This option is not suitable – take the terminal block and connect through it. Another option is Wago terminal blocks. They need to take three pieces – according to the number of wires. In one terminal block, the same wires are connected from the hood and from the shield – phase to phase (here the colors can be different), zero (blue or blue) to zero, ground (yellow-green) to ground.
Air duct for kitchen hood
One of the stages of installing the hood is the selection and installation of air ducts. Air at room temperature is vented from the kitchen, so there are no special requirements for air ducts and you can use any. Three types are commonly used:
- Aluminum corrugated sleeve. It is good because it is easy to give it the desired shape – it easily bends at any angle. Just take a piece of the desired length and give it the desired shape. Disadvantage: the operation of the hood will be noisy, as the air flow causes noise and resonance. The second negative point is that the surface is ribbed, which creates additional difficulties for air flow. Well, one more drawback is that it’s hard to care for: soot and dust clog into the grooves, it’s hard to clean out.
- Plastic (PVC) round air duct. Easy-to-use round polymer pipes. The air duct of the desired configuration is assembled from shaped elements – roundings, bends, adapters, couplings. They are connected to the pipe due to the presence of extensions on the shaped elements. So that during operation the elements do not separate, the joints can be smeared with glue (liquid nails or Moment). Another option is to fasten with self-tapping screws – three or four pieces for each connection. The advantage of PVC air ducts for exhaust hoods is that they are “quiet”, smooth inner walls do not interfere with air movement, and the outer ones are easy to clean. The disadvantage is a more complicated assembly process (compared to aluminum corrugation).
Types of air ducts for kitchen hoods - Plastic square duct. It is also made from polyvinyl chloride (PVC), but has a rectangular cross section. All other characteristics are the same. Rectangular air ducts are used if it is necessary to save space – they are well hidden behind plasterboard partitions, behind stretch or suspended ceilings.
There is another difference between plastic and corrugated duct – the price. Polymers are more expensive. Despite this, if you have the opportunity to install a hood using PVC, install them. With an equal cross section, they provide more efficient air removal, and also make less noise.
The cross section of the pipes for the duct is determined by the size of the outlet on the hood. In the case of rectangular pipes, an adapter is used.
Dimensions of ducts for hoods
Round ducts are available in three sizes: 100 mm, 125 mm and 150 mm. This is the diameter of plastic pipes and corrugated sleeves. There are more sections of flat air ducts and they are presented in the table.
How to choose the size? In the case of round pipes, their diameter must match the diameter of the outlet of the hood. It is very undesirable to put an adapter on the outlet, and then use a smaller diameter duct – this will reduce the rate of air purification. And even if the hood is very powerful, then it will not cope with air purification.
With the choice of the cross section of a rectangular duct – its cross section area should not be less than the cross section area of the outlet pipe. And the connection is made through a suitable adapter.
How to attach the corrugation to the hood and ventilation
If you decide to install a hood and use aluminum corrugation for the duct, you will need to think about how to attach it to the body and to the ventilation. To do this, you need clamps of the right size. They can be metal or plastic.
To connect the hood to the ventilation system, you will also need a special ventilation grill. It has a hole in the upper part for connecting the duct pipe. In the lower part there are holes for removing air from the kitchen using natural circulation at a time when the hood is not working.
A grating with a ledge is suitable for fastening the corrugation – around the hole there is a side of a few centimeters, on which the corrugation is put on, after which it is fastened with a clamp of a suitable size.
By the same principle, a corrugated duct is attached to the hood. It has a ledge on which the corrugation is put on. The connection is tightened with a clamp.
How to fix the duct to the walls
For plastic air ducts there are special fasteners in the form of latches. They are first mounted on the wall using dowels. The installation step depends on the curvature of the track, but on average, 1 mount per 50-60 cm is enough. Pipes are inserted into these latches during installation with little effort.
If the duct needs to be fixed to the ceiling, the same fixings can be used. But if you need to maintain a certain distance from the ceiling, this type of installation will not work. In such cases, they take perforated drywall hangers, fasten them to the ceiling, then use small PVC screws for the exhaust duct to them.
Corrugated air ducts are attached to the walls with clamps or large plastic puffs. If necessary, they are also mounted to the ceiling using perforated aluminum hangers.
Where and how to bring the air duct
Most often, the duct from the hood in the kitchen is connected to the vent through which natural ventilation (due to draft) goes. This is wrong, since in this case most of the grille is closed by an air duct, and air exchange through the remaining available holes will be clearly insufficient.
Correctly connect the air duct to a separate ventilation duct. In this case, the same grate is installed on the hole as in the photo above.
If there is no separate ventilation duct, but there is an outer wall nearby, you can bring the pipe outside by placing a grill on the outside. These are two ways to have normal ventilation and ensure the normal operation of the hood.
How to get outside
To install the hood and bring the duct into the wall, you need to make a hole in it. And this is the only difficulty. Further, an air duct is inserted into this hole, sealed with a solution. Outside, the hole is closed with a grate – so that debris does not get in, birds and small animals do not settle.
To prevent air from the street from blowing into the room, a check valve is installed (in the figure above it is indicated by an oblique line). By the way, it is also desirable to install it when connecting the air duct to the ventilation system – so that odors from the pipes do not enter the room.
The non-return or anti-return air valve is a lightweight plastic or metal plate. It is movably attached in two places to the pipe – at the top and bottom, the petals are supported by a slight spring. While the hood is not working, the valve blocks the access of air from outside. When the hood is turned on, the air flow bends the plate forward, squeezing the spring. As soon as the hood is turned off, the plate returns to its place with the help of springs. If you install a hood without this valve, it may be too cold in the kitchen in winter – outside air will enter the room without any problems.
So that the hood does not interfere with natural ventilation in the kitchen
With the help of a tee and a non-return valve, by the way, you can install the hood so that it does not interfere with the natural ventilation in the kitchen. You will need a special ventilation grill for connecting hoods, a check valve and a tee. A tee is attached to the ventilation grill, an air duct from the hood is connected to its lower inlet, and a check valve is placed on the free outlet, only so that the petals are locked when air passes from the pipe (in the photo below).
How does such a system work? When the hood is turned off, the check valve petals are bent, air from the kitchen enters the ventilation duct through the grill and the open outlet of the tee. When the hood is turned on, the air flow from it unfolds the valve plate, and the air goes into the ventilation system. When the hood is turned off, the springs again open access to air through the tee.
Outwardly, such a system does not look very attractive and it will have to be somehow masked. But this is the only way to connect the hood to the only existing ventilation outlet and not reduce air exchange.