Chimney Duct Installation and Re-routing in Hyderabad
For connecting a chimney’s duct to the outside, cutting a new wall opening where there is none, shortening or re-routing a duct run that is costing suction, and freeing or replacing a non-return flap stuck with grease. Tell us your duct route when you book and we confirm what the job involves and the charge before the visit.
A kitchen chimney’s duct is the pipe that carries the air it extracts to an opening to the outside. A good duct run is as short as the kitchen allows, has as few bends as possible, is no narrower than the chimney’s outlet, and ends in a non-return flap that opens freely. A long, kinked or narrow duct, or a flap stuck with grease, cuts suction even when the motor is healthy, so the duct and flap are checked before any part is quoted.
- Duct work we do
- Connecting the duct to the outside opening, shortening or re-routing a run, freeing or replacing the non-return flap
- Usually part of installation
- Connecting the duct supplied with the chimney to the existing outside opening
- New wall opening
- We cut it ourselves (core cutting), charged extra
- Often extra or arranged separately
- Extra duct pipe, bends or a cowl beyond what came with the chimney
- Weak suction
- The duct and flap are checked before any part is quoted
- Apartments
- We work on your own stretch of duct; shaft or terrace access usually needs society permission
- Before anyone travels
- A probable cause, a price range and the visit charge
What a good chimney duct run looks like
- Short and direct. An opening to the outside close to the chimney, reached with as few bends as possible.
- Within the manual’s limits. Your chimney’s manual usually gives a maximum duct length and number of bends. A duct beyond them will never give full suction, because every extra metre and every bend slows the air.
- Full width. The pipe should be no narrower than the chimney’s outlet. Reducing the diameter to fit an old wall opening chokes the airflow.
- Supported, not sagging. Aluminium flexible duct gets dented behind cabinets or sags above false ceilings, and oil collects in the low points.
- Secure joints. A flexible duct that works loose at the canopy vents the kitchen into the cabinet void instead of outside, which is why the smoke never clears.
- A free-moving flap. The non-return flap at the outlet stops outside air coming back in. When it stiffens with grease, the hood pushes against a plate that barely opens.
- A clear outside end. Mesh or a cowl at the outside end collects dust as well as grease and can silt up within a year or two. A bird’s nest, or an exhaust fan pushing air into the same hole, blocks it too.
Why the duct decides real suction
A chimney’s airflow rating is measured without a duct. Through a long run with bends, a hood rated at 1,400 or 1,600 m³/hr on paper delivers noticeably less.
A high-airflow hood pushed through a long, narrow or sharply bent duct becomes loud without becoming effective, because the extra air it moves is simply fighting the pipe. On these hoods, correcting a bad duct run is often the single most useful thing we do.
A chimney can only push air as freely as its duct lets it out. That is why the duct and flap are checked before a motor is condemned.
Duct arrangements in Hyderabad homes
Where your duct goes decides what can go wrong with it and what can be done. Tell us which of these you have when you book.
| Home | Usual duct arrangement | What usually goes wrong |
|---|---|---|
| Independent house or villa | A short run straight out through an external wall, or a vertical run up through the roof | The non-return flap outside stiffens with grease, and the cowl or mesh at the wall silts up. A roof flap is also exposed to weather |
| Apartment block | The duct leaves the hood, turns up and joins a shaft shared with the flats above and below | A long run with at least one bend and shared grease; a flexible duct that kinks or collapses in tight cabinets; a stiff flap where it joins the shaft |
| Older apartment block | Some vent into masonry shafts that have served several kitchens for decades | Deposits higher in the shaft, which belong to the building rather than your flat |
| Flat with no shaft | A retrofitted run through an external wall, a long flexible duct across the ceiling, or a recirculating hood with no duct | A duct that rises and falls instead of running straight, the flap, and the outside end |
| Island or ceiling hood | The duct usually runs above a false ceiling | Duct work can mean opening a ceiling panel |
The page for each area describes its housing and duct arrangements in more detail. See the areas we cover.
What duct work we do, and what is extra
Kitchens differ, so tell us about your wall, duct route and power point when you book. We confirm what the job includes and the charge before the visit.
Duct work we do
- Connecting the duct supplied with a new chimney to the existing outside opening
- Cutting a new opening through the wall for the duct (core cutting), charged extra
- Checking the duct and non-return flap when suction is weak, before any part is quoted
- Freeing or replacing a non-return flap that is stiff with grease
- Shortening or re-routing a duct run that is too long or has too many bends
- Fixing a flexible duct from hood to shaft that has kinked, collapsed or worked loose
- Cleaning the duct run and flap that belong to your flat, where they can be reached from the kitchen
- Disconnecting and reconnecting the duct when a chimney is dismantled or shifted
Often extra, arranged separately or not included
- Extra duct pipe, bends or a cowl beyond what came with the chimney
- Cutting kitchen cabinets, chimney covers or false ceilings
- Cleaning ducting hidden inside walls or a false ceiling
- Clearing a restriction higher up a shared shaft, which belongs to the building
If the duct needs re-routing, mention it when you book and we will tell you whether we can arrange it. If it needs a new wall opening, we cut it ourselves as an extra. When the restriction is higher in a shared shaft, we say so and explain what the association would need to arrange.
Weak suction: check the duct before the motor
Duct problems are easy to miss because the motor sounds normal. With the chimney on high, feel the air at the outside duct opening. If the fan sounds normal but little air comes out, the duct is blocked, kinked or too long, or the outlet flap is stuck.
Many complaints that sound like a motor fault are actually grease or the duct, and replacing a motor will not fix a blocked shaft. Duct fixes range from straightening a pipe to re-routing it.
More on the other causes in weak chimney suction: cleaning, duct or motor?, and on chimney motor repair.
Ducted or ductless?
If no outside opening is possible, a recirculating chimney with charcoal filters is an option, but it removes smell rather than smoke and grease, so it always feels weaker than a ducted one. Charcoal filters are not washable; they are replaced.
Converting a recirculating hood to a ducted one is sometimes possible and sometimes not. It depends on how far the nearest external wall is, whether the duct could run straight, and what is on the other side. If your kitchen allows a duct, ducting the hood works better than any filter.
How chimney duct work is done
- Share the detailsBrand and model, where the duct goes now (an external wall, a shaft or a false ceiling), which floor the kitchen is on, and photos of the hood, the duct where it is visible and the outside opening.
- Confirm the planWe confirm what the job involves, anything extra and the charge before the visit. If the work needs shaft or terrace access, your association will usually need to approve it and someone will need to unlock access.
- Check on siteFor weak suction, the technician checks suction at the canopy, inspects the duct and non-return flap, then shows you the fault before quoting the final figure.
- Duct workThe duct is run to the outside opening with as few bends as possible, and the flap is freed or replaced where needed.
- TestSuction is checked at every speed with you.
What affects duct work charges
- Whether an outside opening already exists
- Duct length and number of bends
- Extra duct pipe, bends or a cowl beyond what came with the chimney
- Any cabinet, ceiling or wall work
- Wall-mounted, island or built-in chimney
Before anyone travels, you get a probable cause, a price range and the visit charge, which covers travel to your home. If you go ahead with the work, the visit charge is adjusted into the bill. More on how our charges work.
Related services
- Chimney installation and dismantling: mounting height, power point and shifting
- Chimney repair: suction, noise, controls and lights
- Chimney motor repair, when the motor really is the cause
- Chimney deep cleaning, when grease is the real cause
- Chimney brands we service
We serve homes across Hyderabad and Secunderabad. See the areas we cover.
Chimney duct questions
How long can a chimney duct be?
Your chimney’s manual usually gives a maximum duct length and number of bends. Every extra metre and every bend slows the air, and a duct beyond those limits will not give full suction even with a healthy motor, so keep the run as short and straight as the kitchen allows.
What if my kitchen has no opening for the duct?
A ducted chimney needs an opening to the outside. If there is none, we can cut one through the wall (core cutting), which is charged extra, or you can choose a ductless chimney with charcoal filters. Tell us about the wall when you book and we confirm the charge before the visit.
What is a non-return flap, and why does it matter?
It is the flap at the duct’s outlet that stops outside air coming back in. Grease or dust makes it stiffen until it barely opens, and the hood then pushes against a near-closed plate, which costs a surprising amount of suction. We check the flap and the flexible duct on every visit, and a stiff flap can be freed or replaced.
Can you fix the duct in my apartment’s shared shaft?
We work on your own stretch: the flexible duct from the hood to the shaft and the non-return flap where it joins, and we clean the duct run and flap that belong to your flat. When the restriction is higher in the shaft, we say so and explain what the association would need to arrange. If the job needs shaft or terrace access, your association will usually need to approve it.
Will my old duct be reused when I replace or shift my chimney?
Often not. An old duct is often too greasy or too short to reuse, and you will be told if a new one is needed. Old duct pipes with hardened grease, kinks or too many bends may need replacing to bring suction back.
Is the duct cleaned during a chimney cleaning?
A deep cleaning covers the duct mouth at the hood. Ducting hidden inside walls or a false ceiling is not part of a cleaning, and replacing a damaged or very old duct pipe is separate work. See what chimney cleaning includes.
My chimney is loud but does not pull. Is it the duct?
With high-airflow hoods it often is. A hood pushed through a long, narrow or sharply bent duct becomes loud without becoming effective, and shortening or re-routing the duct usually does more than any part. Noise can also come from grease on the fan blades, worn motor bearings, loose screws inside the hood or a loose duct, which is a repair check.
Can a ductless chimney be converted to a ducted one?
Sometimes. It depends on how far the nearest external wall is, whether the duct could run straight and what is on the other side. Tell us the layout when you book and we will tell you whether we can arrange it.
Plan your chimney duct work
Send photos of the hood, the duct where it is visible and the outside opening, and tell us your floor and whether the duct goes into a shaft. We confirm what the job needs and the charge before the visit.