Balanced air distribution
AC duct installation in Al Mawj
In Al Mawj, south Jeddah, ductwork installation needs careful sizing because the modern residential blocks here are spread out and far from the city centre. Alrabih's team designs the duct to distribute cold air evenly from the central unit to every room without loss in transit.
- Sized branches
- Sealed insulation
- Clean return path
Clients We're Proud to Serve
Organisations and companies that trusted Alrabih with their projects.
When you need a properly designed duct fit
- 1
One room cold, another warm
The unit runs but one room is too warm while the next is too cold. The cause is usually unbalanced branches or a diffuser that was never adjusted, not a fault in the unit itself.
- 2
Moisture and sweating on the ceiling
In Jeddah's humid air, uninsulated cold duct sweats on the outside and water collects on the plasterwork. Proper insulation with Armaflex or Kimmco stops the problem before it damages the ceiling finish.
- 3
Installing a concealed unit in a new build
The right time to fit duct properly is during the fit-out, before the false ceiling closes. We agree plenum dimensions, branch sizes and the return-air route at the survey before any work starts.
Who it's for
Fitting a concealed unit in your new villa
Before the false ceilings close, we design the plenums, branches and return-air route to suit the unit and each room in the villa.
Ask on WhatsAppSweating ceiling and uneven airflow in your building
We inspect the existing branches and return-air path, re-insulate the cold duct, and set the dampers so temperature evens out across every section of the building.
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What the duct installation covers
- Supply and return plenums
- Sized branch to each room
- Armaflex or Kimmco insulation
- Diffuser balancing with dampers
- Airflow check before ceiling closes
How we work
How we work
- 1
Site and unit survey
We measure the rooms and study the unit's data and plenum spec, and we settle the return-air route before deciding on branch sizes.
- 2
Design branches and plenum
We size each branch so it takes the right share of air without starving rooms farther from the unit, and we plan a return path with a correctly sized intake opening.
- 3
Fit and insulate
We fix the plenums and branches using SMACNA-standard duct, then insulate every cold surface with a sealed layer that stops sweating in Jeddah's high humidity.
- 4
Balance and hand over
We set each diffuser damper and check airflow in every room with you before the false ceiling is closed, then leave the site clean.
Designed duct or just connected duct?
| Alrabih | The usual way | |
|---|---|---|
| Branch sizing | Calculated per room | Connected without sizing |
| Return air | Routed with a sized intake | Left to chance |
| Duct insulation | Sealed against sweating | Thin or absent |
| Diffuser balance | Damper set per room | All diffusers fully open |
| Pre-closure airflow check | Done with you before closing | Faults found after ceiling closes |
Everything your AC needs, from one team
From system design and duct fabrication to installation, commissioning and maintenance.

Split AC installation
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Duct installation
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Central AC installation
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Duct fabrication
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Cold room installation
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Electro-mechanical works
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Chiller & AHU installation
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HVAC design
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AC repair & faults
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AC cleaning
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Refrigerant charging
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Central AC maintenance
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Chiller maintenance
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AC removal & refitting
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Duct cleaning & sanitising
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AC servicing by brand
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Operation & maintenance contracts
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AHU maintenance
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Fridge & freezer service
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Cold rooms
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Display fridges & chillers
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Factory HVAC
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Warehouse HVAC
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Villa & home HVAC
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Hotel HVAC
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School HVAC
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Hospital HVAC
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Mosque HVAC
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Mall & retail HVAC
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Restaurant & cafe HVAC
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Some of our work
Ductwork, rooftop units and diffusers, from work we've completed in Jeddah.
Customer reviews
What our customers say
- Muhammadramzan 2641
“MashaaAllah. Services are so good. Behaviour and kindness 100/100. Prices are less then Market. Fully recommended”
- shahzeb armani
“Wow. Prices are so comfortable. Outstanding services. People are so talented and nice”
- Tawfik AlyawerLocal Guide
“U can find all u need for air conditioning”
Your satisfaction matters to us! If you had a great experience with us, we'd love a 5-star rating and a kind review.
Worked with us? Leave a reviewService areas
We come to you anywhere in Jeddah
From Al Shiraa and Al Yaqout in the north to Al Thaghr and Al Quraiyat in the south, with our base in Al Aziziyah.

What sets this district apart
Al Mawj is a modern residential district with villas and spacious apartment blocks built to open floor plans and long hallways that need balanced air distribution. The high humidity in south Jeddah means the insulation must be thick to prevent condensation on cold ductwork, and the duct size itself affects air velocity and cooling efficiency across the long distances between wings.
Al Mawj sits in south Jeddah, a modern residential area with spacious blocks and scattered villas.
Most villas and modern apartment blocks in Al Mawj rely on a central AC unit with a concealed duct system routed through walls and ceilings.
The AC setup in Al Mawj
- 1
Central ductwork with heating and cooling unit
Modern villas in Al Mawj typically have a single central unit with one unified duct network serving the entire home.
- 2
Ductwork with separate thermal zones
Larger apartment blocks sometimes need ductwork split into independent thermal zones for separate temperature control and energy savings.
- 3
Insulated ductwork against humidity and condensation
Ductwork in Al Mawj is wrapped in thick insulation because the high southern humidity causes condensation on cold pipes.
Before the visit
Before our visit in Al Mawj
- 1
Ensure team access to ceilings and walls
Tell us if there is heavy furniture or obstacles blocking the passages and walls where we will run the ductwork.
- 2
Confirm the central unit location
We need to know where the central unit will sit (mechanical room, attic) before the installation day.
- 3
Check your home's electrical capacity
Contact your contractor or electrician to confirm the wiring can handle the load of the central unit and blower fan.
More districts for AC duct installation
Other services in Al Mawj
FAQ
Questions about AC duct installation
Why does duct in Jeddah sweat more than elsewhere?
Jeddah's outdoor air carries high moisture because of its coastal location. When that air touches a cold duct surface, the moisture condenses immediately. Insulating with a thick enough layer of Armaflex or Kimmco, with all joints sealed, raises the outer surface temperature above the dew point and stops the sweating.
Does a longer branch deliver less air to the room?
Yes, a longer branch resists airflow more than a short one. This is why we size each branch individually, so near and far rooms receive balanced quantities of air, and we complete the adjustment with dampers during start-up.
How do you size the return-air opening?
The intake opening must be large enough so the unit does not work against negative pressure that strains it. We check the unit data and plenum requirements and decide size and position at the survey, because placing it behind a closed door or away from occupied areas changes the calculation.
Does a large room need more than one air outlet?
Usually, yes. A long majlis or a wide living room cannot be served by one outlet, because the air cools one end and leaves the other. We spread the outlets along the room, split the branch between them, and keep them away from the return grille so cool air does not go straight back to the unit.
Does the duct material affect sweating and airflow balance?
Yes. Sheet metal duct holds its shape under air pressure, so flow quantities stay as designed. Flexible duct can compress or sag, changing its cross-section and upsetting the balance. We therefore fabricate the main branches from galvanised sheet in our workshop and use flexible duct only for the shortest possible connection at each diffuser.
How does hidden ductwork ensure cool air reaches every room evenly?
We size the duct branches based on your central unit's capacity and each room's area, then balance the diffusers so cool air reaches distant corners with equal force.
Villas in Al Mawj have long runs, does that complicate installation?
Yes, long distances need custom ductwork design and may require a more powerful central unit to maintain air pressure, and we measure each section before installation.
Southern humidity may cause condensation on the pipes, how do you protect them?
We wrap cold duct pipes with thick insulation to prevent condensation in high humidity, and ensure any water that gathers drains away safely.
The central unit and ductwork need adequate power, what do you check?
We check your home's electrical capacity and wiring before installation, and confirm the circuit breaker matches the load of the central unit and fan.












































































