Balanced air distribution
AC duct installation in Al Majami'
In Al Majami', far north Jeddah, duct installation in dispersed villas requires careful planning for long runs and the humid coastal climate. Alrabih's team designs a balanced system with strong thermal insulation to ensure effective air distribution despite environmental challenges.
- 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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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 Majami' is an expansive residential area at the far north of Jeddah with dispersed villas on wide open plots, and urban expansion here is still ongoing. Central AC with concealed ducting is the first choice for modern villas, but long distances between rooms mean longer duct runs that risk pressure loss, so we carefully design duct diameter and plenum size. High coastal humidity makes thermal insulation critical to prevent year-round condensation. Roof access is usually easy, but wall cavities may be limited in relatively older villas here.
Al Majami' sits at the far north of Jeddah, an expansive residential area with dispersed villas on wide land, directly exposed to coastal humidity.
Most villas in Al Majami' are relatively new with wide open roofs, but long distances between rooms mean the duct needs a larger diameter.
The AC setup in Al Majami'
- 1
Concealed duct with larger diameter for long runs
Spacious villas in Al Majami' need a larger duct diameter than standard to minimise pressure loss across long distances.
- 2
Double thermal insulation and protected condensation drainage
High coastal humidity requires heavy insulation and a separate drainage pan to avoid moisture accumulation in cavities.
- 3
Outdoor unit in climate-sheltered location
We choose an outdoor unit location away from sea wind and salt exposure, such as a sheltered villa side or behind a barrier.
Before the visit
Before our visit in Al Majami'
- 1
Open available cavities for roof ducting
If wall cavities are insufficient, arrange with a contractor to open the roof or foundation route before the visit.
- 2
Choose a sheltered safe location for the outdoor unit
Choose a sheltered spot away from wind and salt, like a protected house side or behind a fence, and confirm power is available.
- 3
Ensure safe access to roof and external passages
Open roof doors and clear external paths of obstacles so the team can reach all areas safely with equipment.
More districts for AC duct installation
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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.
My villa is very large with rooms far apart, will air reach all areas?
We size the duct diameter and plenum based on long runs to minimise pressure loss, and balance flow at every outlet.
The villa has limited wall cavities, must we cut through walls?
We assess cavities first, and may choose a roof or foundation route instead of cutting walls if possible.
The extreme humidity at the coast, will the duct be damaged by condensation?
We insulate the duct with a thick thermal layer and drain condensation into a separate pan for complete moisture protection.
Where should I place the outdoor unit away from salt and wind exposure?
Choose a sheltered side of the villa away from direct wind, or behind a barrier if possible, and let us know the location.
