Why Every Indian Kitchen Needs a Ducted Chimney

In the past, Indian houses featured masonry chimneys built into the walls that allowed spice fumes and oil smoke to rise naturally out of the home. With modern flat living, these natural exhausts are gone. Today, you must choose between an exhaust fan or an electric chimney to maintain a healthy living environment.

Can an Exhaust Fan Replace a Chimney?

To save costs, many consider using only an exhaust fan. However, from a mechanical engineering perspective, an exhaust fan is often a partial solution at best.

  • The Problem of "Channeling": Most exhaust fans are placed high on a wall near a window. If that window is open, the fan simply pulls fresh air from the window and throws it right back out, leaving the stagnant, polluted air over the stove untouched.
  • Health Risks: Combustion of LPG produces Carbon Dioxide, steam, and traces of Carbon Monoxide. Without immediate extraction at the source, these gases—along with pungent masala fumes—circulate through your home, potentially causing headaches, nausea, and sinus issues.

How to Calculate the Required Suction Power

Don't choose a chimney based on width (60cm vs 90cm) alone. The most critical specification is the Suction Capacity, expressed in Cubic Meters per Hour (m3/hr).

The "Rule of Ten"

As a rule of thumb, a chimney should be able to exhaust at least 10 times the volume of air in your kitchen every hour.

Example Calculation:

  1. Kitchen Dimensions: 3m (Width) x 4m (Length) x 2.5m (Height) = 30m3 volume.
  2. Required Suction: 30m3 x 10 = 300 m3/hr.

Engineer's Tip: While the math suggests 30m3/hr, standard Indian cooking involves heavy frying. I recommend a minimum of 1100 m3/hr to 1200 m3/hr to account for ducting resistance and heavy spice fumes.

Ducted vs. Recirculating Chimneys

  • Ducted (Highly Recommended): These use a pipe to send burnt gases and oils completely outside. This is the only way to remove Carbon Monoxide and heat effectively.

  • Recirculating: These use charcoal filters to scrub smells and then push the air back into the kitchen. While they catch some oil, they do not remove heat or combustion gases, making the kitchen hot and stuffy.

    ADVERTISEMENT

Optimizing Kitchen Ventilation

If you must use an exhaust fan, ensure cross-ventilation. Fresh air should enter from the opposite side of the kitchen, flow across the room, and exit through the fan. In air-conditioned flats, you may need to leave a door slightly ajar to a ventilated area to allow fresh air to replace the air being sucked out.

2026 Tech Upgrade: BLDC & Autoclean

Modern chimneys have evolved beyond your basic fan.

  • BLDC Motors: Brushless motors are quieter and more efficient than traditional AC motors.
  • Thermal Autoclean: A heating element melts internal grease into a collector tray, maintaining that critical suction power we calculated above.