Working Principal of Kitchen Chimney :
A kitchen chimney is a contraption that vents smoke, moisture and grease-filled air. It reduces indoor air pollution, keeps your kitchen clean and prevents breathing problems.
Cooking releases a lot of solid and liquid microscopic particles called particulates or particulate matter (PM). They are approximately 1 to 10 micrometers in diameter, and consist of organic and inorganic substances like soot, smoke, water vapor, oil fumes, aromatic fumes and bits of food. Particulates are harmful for health and cause respiratory disorders. They need to be removed through chimneys, exhaust fans, windows and ventilators.
In modern Indian homes, chimneys are especially important due to the nature of the cuisine. Indian cooking entails plenty of frying and sautéing. A lot of our dishes have the typical ‘tadka’ style of preparation which produces clouds of fumes filled with oil, spices, organic matter and moisture.
If these pollutants are not immediately expelled, they stick to walls, ceilings, cabinets and appliances, and over time, impart a yellowish tinge to things, giving the kitchen a grimy look. Therefore, to prevent your house and everything in it from aging faster than they should, it is recommended that you install a good kitchen chimney.
How a kitchen chimney works ?
A chimney is essentially a ventilation device. It collects and routes out polluted air, leaving the indoor air refreshed and clean. A kitchen chimney is a necessary gadget for those who love cooking and entertaining guests at home with fresh home-cooked meals.
The mechanism behind a kitchen chimney is very simple. Smoke and oil droplets emitted during the cooking process are drawn into the chimney. The grease is trapped by the filters while the moisture and smoke are channeled out through the ducts and released into the outside environment.
A kitchen chimney can be ducted or ductless. The ways both these systems work have a few differences. A ducted chimney comprises of a hood, a motor, filters, hose pipes/PVC pipes and an elaborate ducting system. It requires proper plumbing for the ducts to be laid out and integrated into the masonry. It is generally placed directly above the stove to ensure maximum ventilation.
A ductless chimney is just like a ducted chimney except it has an additional carbon filter and lacks ducts. The polluted air first enters the primary filter which removes the oil droplets. Then the air moves through the carbon filter which eliminates bad odors, smoke and humid air. The recycled air is then released back into the house and not expelled like in a ducted chimney. This is the main difference between a ducted and a ductless chimney.
Ducted chimneys completely vent out the polluted indoor air while ductless chimneys purify it and route it back into the house. Ducted chimneys are more expensive than ductless varieties. But since their filters are washable, they have far less operating costs. They are also easy and cheap to maintain.
On the other, although ductless chimneys cost less during the initial installation, they have higher operating costs because carbon filters are not washable and need to be replaced every few months. Ducted chimneys are also more efficient as they have a higher suction power. They can remove heat and prevent condensation.
Ductless chimneys are not very good at keeping temperatures down. However, they are more flexible, and can easily be dismantled and relocated around the house.
Type of filters
Now let us focus on the types of filters. Depending on the material and the kind of construction, chimney filters can be categorized into 3 types. First, there are the mesh filters or cassette filters. These are ideal for cooking styles that do not involve much oil. Then there are baffle filters which are great for Indian cooking. Lastly, there are charcoal filters which are used for removing pungent smells.
Let us now analyze each filter in a little more detail.
1. Mesh or cassette filter
This kind of filter is commonly used by all major kitchen chimney brands. It comprises of a thick mesh of aluminum or stainless steel. The mesh has multiple layers with numerous tiny pores for retaining and removing oil particles. The remaining smoke, carbon, water vapor and bad odors are ejected from the house through ducts.
Stainless steel cassette filters are costlier than their aluminum counterparts. They are heavy but easy to clean and maintain. Aluminum filters, on the contrary, are lightweight and easy to handle, but cleaning them can be a little tricky. Both stainless steel and aluminum mesh filters need to be washed once a week with dishwashing liquid and/or baking soda.
Please note that mesh filters are not suitable for Indian culinary preparations as they are not built to handle large amounts of oil-infused aerosols. The pores get clogged with oil which hampers the air flow and suction power of the chimney. Cassette filters are also maintenance-heavy and have recurring operating costs.
2. Baffle filter
A baffle filter controls the flow of the air drawn up by it. It adopts a unique ‘cut and chop’ technique to separate the oil and food particles from the smoke. It is made up of multiple curved surfaces which retain oil and grease while the unwanted smoky air is expelled through the PVC ducts. The retention of oil by the filter does not hamper air suction.
Hence, this kind of filter is best suited for Indian households. They are easy to clean and maintain. They are dishwasher-safe and can be washed using regular soap or liquid detergent. Baffle filters are generally made from stainless steel, although some traders also sell aluminum baffle filters.
The biggest plus-point of baffle filters is that they are extremely strong and durable. They have a sturdy construction designed to withstand the rigors of oil-rich cooking methods. They last longer than cassette filters and are maintenance-light.
3. Charcoal filter
Spice-laden cooking fumes can cause coughing, sneezing and irritation to the eyes, nose and throat. They must not be allowed to stagnate but immediately removed from the cooking area. This is where charcoal filters come in. They remove cooking smells like no other. Their surface area is artificially enhanced to attract pungent substances.
The pollutants stick to the surface of the carbon molecules by a process known as adsorption. They get taken out of the air flow, and are thus, prevented from circulating in the air. Charcoal filters are not washable. They have to be replaced once they are fully saturated. This means they come with an added running cost.
Types of chimneys
Depending on the way it is installed, a kitchen chimney can be classified into 4 main types: wall-mounted, island, straight-line and built-in. Wall-mounted chimneys are the commonest kind of domestic chimneys. They are mounted on walls with the kitchen hood positioned directly over the cooktop.
Island chimneys are secured to the ceiling and hang freely over the cooking platform. They are perfect for western kitchens with hobs where the stove or hot plate is integrated into the counter top.
Straight-line chimneys are conventional kitchen chimneys. They are available in ducted and ductless variants. Built-in chimneys are integrated into the cabinetry above the cooktop. They remain hidden from view and blend in seamlessly with the decor of the kitchen.