Desert cooler, proper duct
Evaporative (desert) duct installation in Al Najmah
In Al Najmah, north Jeddah, evaporative duct installation serves small hotels, restaurants and mid-sized commercial buildings needing cost-effective cooling. We mount the cooler on the roof and run large duct through corridors and halls to distribute cold air.
- Sealed roof
- Galvanised duct
- Air changes
Clients We're Proud to Serve
Organisations and companies that trusted Alrabih with their projects.
When you need evaporative cooler duct
- 1
A large workshop or warehouse
Large industrial spaces get very hot in Jeddah summers and split units are expensive to run there. An evaporative cooler with distribution duct brings air to work areas at lower running cost, provided the space is ventilated and not sealed shut.
- 2
A majlis tent or seasonal space
Outdoor majlis areas and seasonal tents do not suit split AC units because of the structure. Evaporative duct delivers a cool air stream as long as the space is open enough for air changes, which the survey confirms.
- 3
Old duct with poor airflow
Old sheet duct cracks over time and air leaks from the joints before reaching the space. On site we check whether the problem is leaking duct, poor distribution, or the cooler size itself.
Who it's for
Need to cool a large workshop at reasonable running cost
We survey the workshop and check its ventilation, then run galvanised duct from the roof cooler to the work areas with exhaust openings that keep air moving through the space.
Ask on WhatsAppYou have an outdoor majlis that needs seasonal cooling
We check how open the majlis is and assess its structure, then design the duct route and exhaust openings so cool air reaches the seating area without humid air building up inside.
Ask on WhatsApp
What the work covers
- Weatherproof roof collar fitted
- G90 galvanised duct runs
- Branch and air outlet connections
- Exhaust openings for air changes
- Airflow check after start-up
How we work
How we work
- 1
Site survey first
We visit, measure the space and check how open it is, because evaporative cooling needs enough ventilation; without it humidity rises inside and the cooling effect drops.
- 2
Plan the duct route
We plan the main duct run, branches, air outlet positions and exhaust opening locations, and show you the layout before any work starts.
- 3
Install duct and seal roof
We open the roof, fit and seal the collar against leaks, then run the galvanised duct and hang it on proper supports so it does not sag.
- 4
Start-up and test
We run the evaporative cooler and check that air reaches every outlet and that the exhaust openings are working so fresh air is visibly moving through the space.
Planned duct or a quick run?
| Alrabih | The usual way | |
|---|---|---|
| Roof seal | Weatherproof, sealed collar | Silicone that cracks in heat |
| Sheet | G90 galvanised | Unspecified gauge |
| Exhaust | Sized openings for air changes | Left to chance |
| Space suitability | Confirmed by survey | Not checked |
| Duct supports | Fixed hangers along the full run | Duct left unsupported |
Everything your AC needs, from one team
From system design and duct fabrication to installation, commissioning and maintenance.
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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.
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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 Najmah holds mid-rise commercial buildings, small hotels, restaurants and retail shops, most with exposed but limited roof space compared to warehouses. Evaporative cooling suits these buildings because the seasonal dry air in this northern area boosts evaporation efficiency, and careful outlet positioning ensures cold air reaches every floor and room without gaps.
Al Najmah sits in north Jeddah, a district of commercial buildings, shops and small hotels with limited roof space.
Most commercial buildings here lack full central air conditioning, and evaporative duct offers quick installation and low maintenance.
The AC setup in Al Najmah
- 1
Roof cooler with multi-branch duct to serve multiple floors
The large duct branches to reach different floors without sharp pressure loss.
- 2
Exhaust openings in halls and room corridors
We open several outlets along long corridors and main halls to ensure cold air spreads evenly.
- 3
Roof and duct weatherproofing against seasonal moisture
We seal all ductwork and openings carefully to prevent rain and moisture seeping to lower floors.
Before the visit
Before our visit in Al Najmah
- 1
Clear a safe mounting point on the roof
Remove any equipment or storage from the proposed roof point and tell us if the roof is rigid or sloped.
- 2
Confirm internal duct routing is feasible
Ensure corridors and halls have room for a large-bore duct without blocking movement or clashing with the design intent.
- 3
Prepare a dedicated electrical circuit for the cooler
Confirm there is a suitable electrical circuit on the roof or in the nearest safe location to power the cooler.
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FAQ
Questions about Evaporative (desert) duct installation
Does evaporative cooling work in Jeddah in summer?
Evaporative cooling relies on water evaporation and weakens when humidity is high. In Jeddah, humidity is higher near the coast and lower inland. The survey decides whether the space and the season are suitable, which is why we do not start before visiting the site.
Why do exhaust openings matter as much as the duct runs?
An evaporative cooler pushes fresh air in continuously. Without an exit path, humid air builds up inside and the felt temperature rises. Properly sized exhaust openings keep air moving through, not piling up, and that is the core of how this type of cooling works.
What sheet do you use for the duct?
We use G90 galvanised steel sheet, which resists rust in Jeddah's humid and salty air. The duct sections are formed in our workshop before being taken to site, then hung on supports along the run to stop them sagging.
Can one cooler supply duct to more than one area?
Duct can be branched from one unit to more than one outlet, but each branch reduces the airflow at every opening. The survey decides whether the cooler has enough output for the total area, or whether a separate unit for each wing is the better answer.
Can evaporative cooler duct run through a false ceiling?
Evaporative cooling depends on continuous air movement and exchange, which requires exhaust openings in the same space the duct serves. A false ceiling restricts that flow unless dedicated openings lead air out of the building. The site survey decides whether the structure allows it, because the duct run and the exhaust are designed together as one system, not separately.
Does evaporative duct suit my small hotel in Al Najmah?
Yes, if you have open reception areas and long corridors. We visit to check the roof and calculate the duct length needed for each floor.
The building is hemmed by others, does this affect evaporation efficiency?
Nearby buildings may reduce the outdoor airflow the cooler needs, but we assess the site first to confirm whether evaporation is suitable.
Humidity in Al Najmah can be high near the coast, does this weaken cooling?
Yes, seasonal coastal humidity reduces evaporation efficiency, but on most days the air is dry enough for cooling to be effective.
Where does the cooler's water and drainage go?
We prepare a safe drain point on the roof away from wiring, and ensure water does not seep inside during seasonal rain.
