Features of recirculation hoods

Speaking in technical terms, recirculation or circulation hoods for the kitchen are not inherently because they do not remove polluted air, but clean it with of filters and return back. From the point of view of specialists, this type of ventilation is considered the most inexpensive. For many kitchens, filter installations are the most acceptable option.

What's the Difference

Hoods are of two main types. Evacuation (flow) carry out the withdrawal of polluted air outside the room through the ventilation shaft of the building. The recirculation system works on the principle of a closed cycle; it is not necessary to bring the exhaust ducts to stationary ventilation. When using the recirculation mode is not required to carry out any serious work or rearrange the furniture in the kitchen to install the hood. The polluted stream is pumped through filters that remove the smallest splashes of grease and unpleasant smell from it, the cleaned air mass is returned back to the room.

Flow system

Evacuation hoods (with a vent to ventilation) are more powerful, but they have many disadvantages:

• separate connection to the mine ventilation;
• mandatory installation of a check valve;
• need a constant flow of fresh air from the open window;
• separate costs for the installation of the duct in the case of a remote location of the standard entrance to the ventilation shaft;
• the installed system removes the heated air in the winter time; instead, cold air flows from the street, which negatively affects the heating, in the summer everything happens the other way around.

Therefore, hoods of this type are best used in specialized kitchens. cateringwhere they fully justify the connection costs. In apartments, especially small ones, it is more convenient and more rational to use recirculation systems.

The principle of the recirculation hood

In high-rise buildings, there are often problems with the ventilation system: there is not enough traction or there is no ventilation at all due to clogged internal ducts. This is where an exhaust hood comes to the rescue, working without being connected to ventilation, or simply of the circulating type.

Fan rotates horizontally above the hob, pulling into the bell of the system streams of cooking-polluted air. On the way, this stream encounters special filters that precipitate particles of fat on the mesh surface. Then there is a cleaning from smells, after that the air stream comes back to the room. After cooking, turn off the system and open the window to air to restore normal atmosphere.

Important! Humidity in the kitchen will not go anywhere without systematic ventilation, and the influx of fresh oxygen will only refresh the entire room.

In modern city apartments hermetic double-glazed windows are installed, which eliminate noise from the street, but the air flow into the room should be carried out constantly.

Work recirculation hood

Advantages and disadvantages of the design

Installation of hoods This type does not differ from the standard placement of similar household appliances, but their autonomy much higher. They do not have a binding to the ventilation system, so the designers have developed a number of compact hoods pull out typewhere recycling is applied. They are called telescopic hoods. During operation, they filter by creating strong lateral thrust, sucking up all contaminants with the air flow. After shutdown, the system is recessed into the tabletop, very convenient and original.

Merits

In this type of device, the performance and power is slightly lower, but it has allowed manufacturers to reduce their cost, which only pleases users. All components of the systems are less stressed, so they can operate without trouble for much longer.

In the operation of such a system, there is no place for inverse propulsion.The autonomous arrangement allows free installation of the plate - users place it where it is most convenient for them, regardless of the location of the entrance to the ventilation shaft.

Recirculation hood in the kitchen interior

disadvantages

The biggest drawback of devices with recirculation is the frequent replacement of filters, which occurs with this type of hood at least 1-2 times a year. Moreover, a combination of fat and carbon filters is used for high-quality filtration. Fat filters can be simply washed as greasy dishes using special tools (read more, how to clean the hood from fat).

When buying, choose popular models with standard sizes - it will be easier to find replaceable cassettes.

The downside is that such systems cannot be installed above gas cooking surface - they do not cope with the decomposition products of gas during combustion, while oxygen is burned out, recycling becomes ineffective and meaningless.

What filters apply

Ordinary mesh From the metal in the lower part of the housing, recirculation hoods are a necessary filtration minimum for any kitchen.They are designed to screen out small particles of fat from the air. Their action is quite simple: passing through a frequent metal mesh, polluted air flow leaves small particles of fat on their surface. The mesh pattern is more complicated and smaller, the greater the amount of fat left on it. After a certain time, the grid is removed and washed from the fatty deposit.

As a rule, the grids are made of stainless metal, in low-end models - high-strength aluminum.

Additional filters are used for cleaning odors:

1. Disposable liners from paper, a synthetic winterizer or a flizelin. Replacement is made when the drawing on them becomes invisible.
2. Acrylic, are found quite infrequently, but they are already reusable. When washing them, you must act very carefully, never squeeze, so as not to disturb the location of the fibers.
3. Coal Filters are more dense, therefore they retain the unpleasant odors of burned oil. They are able to effectively clean the air. Cartridges with spent carbon filters are not reused, but replaced with new ones. The frequency of their replacement depends on the intensity of operation of household appliances.

Carbon filters

Any manufacturer of exhaust, both recycling and other samples, where there are filters, should indicate in the attached instruction manual the terms of their replacement. Some set the frequency of not more than 3 months, and others after prolonged use for six months.

The most advanced models of cassette filters are supplied indicatorsthat report marginal clogging. It is quite convenient - you will immediately find out the exact frequency of replacement. When selecting a cassette, pay attention to the absence of gaps; you simply cannot install oversized filters.

Filter Myths

Among users there are judgments about the benefits of various models of hoods. Basically, the debate is about the effectiveness of filters and the quality of removing harmful impurities.

Low filtration efficiency

No exhaust system removes all odors from the kitchen area by 100%. The polluted air exhaust system is not suitable for all city apartments due to clogged ventilation ducts and shafts in apartment buildings. It is necessary to make separate conclusions from each apartment - you need a special permit. The main task of any hood is removal. combustion products, fat drops and soot, because their deposits on furniture and walls do not add surroundings to the interior of the room, and they are harmful to health. This problem is perfectly handled by the filters of the circulation system.

By the way, evacuation systems also have filters that protect the engine and air ducts, they also need to be periodically changed.

We conclude: regardless of the model of the hood, the complete removal of unpleasant odors is basically impossible. Both systems adequately cope with the task of removing soot and fat drops.

Recycling systems are more expensive

Now a little arithmetic: a kit for connecting a flow-through system to house ventilation will cost no less than 1 thousand rubles, if you need to hide air ducts, then add another 500 rubles to PVC pipes. Installation work plus a resolution - another 4 thousand rubles, a total of at least 1000 + 500 + 4000 = 5.5 thousand rubles. The cost of additional ventilation will not be considered.

Coal filters of recirculation hoods cost at least 400 rubles, for a year they need no more than 2-4 cassettes. We get 800—1600 rubles. in year. As a result, we can use the recirculation system for at least 3.5 years, and a maximum of about 7 years, or spend one time on connection hood evacuation type. In the calculations, we did not take into account that the filters are also in direct-flow systems, which also need to be changed.

Conclusion: the circulation hood is economically beneficial, the cost of replacing filters is evenly distributed over the years of operation.

Difficult to find filters

A fundamentally wrong statement: consumables, which include carbon filters, are made by other manufacturers, sometimes they even better qualitythan coming with a hood. Mark-up on the brand is not made, and to acquire the necessary filters is not difficult.

Filters degrade performance

Another misconception, not supported by figures - no one has ever carried out research on this topic, much less any measurements or comparisons of characteristics. Modern carbon filters are very thin, they can not affect the power or exhaust system performance.

The metal grids, which are present in all types of extracts and periodically washed, are clogged with fat.

Losses are present at montage direct-flow systems: one turn reduces efficiency by 10%, and without them there will be no hidden retraction - at least two bends will be necessary.Consider: it was 265 m³/ h according to the instructions, made a challenge with two turns, minus 20% in the end got 265-53 = 212 cubic meters. m / h

Conclusion: do not believe the unverified information and false myths. Power and performance is indicated taking into account the installed filters.

Making the right choice

Autonomous type circulation hoods have different sets of functions that make them a little more expensive, but contribute to the convenience of working with them:

• touch screen panel for control;
• timer programmed for auto power on and off;
• automatic sensors that turn on the fan depending on the temperature or humidity of the air;
• separate control panel at a distance.

The main parameter when choosing a recirculation system is its dimensions.

Important to remember! Acquire only such a model that in its functional abilities and size is perfect for your cooking stove.

Hood dimensions should be several centimeters wider than your plate: only in this case, the intake of polluted air will be maximum, accordingly, the efficiency of cleaning the air flow will be much higher.