Balanced air distribution

AC duct installation in Petromin

In Petromin, south Jeddah, duct installation in warehouses and administrative offices demands precise design to spread air across wide open spaces. Alrabih sizes the plenum and branches to match the unit, insulates cold duct to prevent sweating in Jeddah's humidity.

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  • Sized branches
  • Sealed insulation
  • Clean return path

Clients We're Proud to Serve

Organisations and companies that trusted Alrabih with their projects.

  • Saudi Aramco
  • Ministry of Energy
  • Royal Saudi Land Forces
  • Royal Saudi Naval Forces
  • Al Baik
  • Centro Hotels by Rotana
  • King Abdullah Economic City
  • First Mills
  • Juffali
  • eXtra
  • Dr. Soliman Fakeeh Medical Center
  • Alesayi Motors
  • Abu Zaid
  • Water Desalination
  • Attieh Steel
  • SSCO
  • Creet
  • Emad Rizq
  • Alfaneyah
  • Rawat Alam Al Tasmeem
  • IBI Magix Arabia — Construction Services
  • Midtown for Construction
  • Petra Engineering Industries Co.
  • Hyrmas
  • Batterjee Medical College
  • Advanced Horizons Contracting Company
  • D.Metals
  • Benchbox — Masters of Space
  • Sadafco
  • Umm Al-Qura University
  • Saudi Arabian Drug Store (SADS)
  • Foamco
  • Ahmad A. R. Bin Afif Industries Co. (Sandwich Panel Factory)
  • Namariq
  • ALS

When you need a properly designed duct fit

  1. 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. 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. 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.

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  • Sweating 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
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How we work

How we work

  1. 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. 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. 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. 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?

AlrabihThe usual way
Branch sizingCalculated per roomConnected without sizing
Return airRouted with a sized intakeLeft to chance
Duct insulationSealed against sweatingThin or absent
Diffuser balanceDamper set per roomAll diffusers fully open
Pre-closure airflow checkDone with you before closingFaults found after ceiling closes

Everything your AC needs, from one team

From system design and duct fabrication to installation, commissioning and maintenance.

Some of our work

Ductwork, rooftop units and diffusers, from work we've completed in Jeddah.

  • Galvanized rectangular duct trunk with branch takeoffs and round diffusers, hung from a black ceiling, a Carrier unit visible behind — interior finishing stage.
  • Round diffusers and a spiral duct trunk in a tiled stairwell service shaft.
  • Rooftop ductwork and an exhaust fan, with Jeddah buildings in the background.
  • Rooftop packaged AC units with rectangular duct transitions, city buildings behind.
  • Insulated rooftop duct run beside a packaged unit, a warehouse roof in the background.
  • A grid of round diffusers in an open-plan office ceiling, mid-construction.
  • An insulated rooftop duct elbow, against a mountainous backdrop.
  • Large insulated ductwork running along a factory ceiling, with workers visible below.
  • A yellow round diffuser mid-installation, with spiral duct and a suspended ceiling grid.
  • Duct insulation wrap in progress on a construction site, bare duct still exposed.
  • A black-painted duct trunk with round diffusers and track lighting, in a finished retail interior.
  • An indoor AHU unit connected to round ductwork in a mechanical plant room, exposed concrete ceiling.
Similar project? Send us the details

Customer reviews

What our customers say

4.8

From 10 Google reviews

  • 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”

Read every review on Google

Your satisfaction matters to us! If you had a great experience with us, we'd love a 5-star rating and a kind review.

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Service 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.

Map of Jeddah by sector, with Alrabih's base in Al Aziziyah
Don't see your district?Message us. We most likely cover it.

What sets this district apart

Petromin's buildings mix large industrial units with administrative offices and warehouses, featuring high ceilings and open spans that need balanced cold-air distribution. Insulated duct is essential here because coastal humidity causes condensation on unprotected pipes, and large spaces mean unbalanced flow leaves warm corners untouched. Coordinating with the site manager before work starts ensures access to every installation point.

Petromin, in south Jeddah, is a zone of warehouses, industrial units and offices with open spans and high ceilings.

Most central units serving Petromin cover areas exceeding 500 square metres, requiring multi-branch duct designs.

The AC setup in Petromin

  1. 1

    Multi-branch central duct system

    Large warehouses and offices in Petromin rely on a single central unit with duct branching to several zones.

  2. 2

    Fully insulated duct runs

    All cold duct sections are wrapped in thermal insulation to prevent condensation loss and heat gain in the coastal environment.

  3. 3

    Balanced diffuser outlets on each branch

    Each duct branch carries multiple balanced outlets to ensure even airflow across the wide open area.

Before the visit

Before our visit in Petromin

  1. 1

    Mark planned duct routes in advance

    Tell us which ceiling and wall paths are available before we visit so we can check them for electrical conflicts.

  2. 2

    Coordinate safe site access with management

    Inform site management of the installation date, team size and equipment needed so access and movement are safe.

  3. 3

    Confirm power points for the central unit

    Verify you have a strong power point near the planned central unit location that meets the unit's electrical requirements.

More districts for AC duct installation

Other services in Petromin

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.

Do our large warehouses need complex duct layouts?

Yes, we design balanced branches covering the whole warehouse evenly and test pressure at every diffuser to confirm proper distribution.

Our coastal humidity is high, how do you protect the duct?

We insulate all cold duct with a thick insulation layer to prevent water condensation on the pipes in coastal humidity.

How do you reach installation points in our high ceilings?

We bring scaffolding or lifts based on ceiling height and coordinate with site management to ensure safe installation.

Does the duct take up storage space in the warehouse?

We route the duct through the ceiling or upper walls wherever possible to preserve floor space for storage and work.

The Jeddah corniche in cool weather

Get even airflow in every room

WhatsApp a photo of the floor plan or site and your unit details, and we will book a survey in your district, Saturday to Thursday.

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