Design before you buy
HVAC design in Al Mahjar
In Al Mahjar, south Jeddah, HVAC design must come before purchase, as the residential and commercial buildings there need precise heat-load calculations based on their location and sun exposure. We size each room's needs and select the right system type before any equipment investment.
- Accurate heat loads
- System selection
- Duct drawings
Clients We're Proud to Serve
Organisations and companies that trusted Alrabih with their projects.
Who needs a considered design?
- 1
Owner planning a new build
Before walls and ceilings are finished you still have the chance to route ducts and place units correctly. Early design prevents costly surprises during fit-out and delivers rooms that cool evenly from the first day of operation.
- 2
Architect or contractor needing drawings
The project needs mechanical drawings to co-ordinate with the structure, electrical and plumbing trades. We produce duct layout drawings, equipment positions and installation heights in a format the site can use directly.
- 3
Existing building with uneven cooling
Some rooms stay hot even with the AC running while others are over-cooled. The cause is usually wrong airflow distribution or uncalculated capacity. A redesign finds the fault and defines what needs changing before any new purchase.
Who it's for
Building a villa and want design before fit-out
We calculate the heat load for every room in the villa and draw duct routes before ceilings are closed, so you avoid breaking the finished work later.
Ask on WhatsAppRunning a commercial building with hot rooms
We review the current airflow distribution and recalculate loads per space, then identify faults in the ducts or equipment and draw the required changes before any purchase.
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What the design covers
- Heat load per room
- Right system type selected
- Equipment from authorised brands
- Duct distribution layout drawings
- Equipment schedule for construction
How we work
How we work
- 1
Gather building data
We ask for the architectural drawings or visit the site to measure spaces and record glazing, orientation and internal loads from people, equipment and kitchens.
- 2
Calculate heat loads
We calculate the heat load for each space separately, accounting for Jeddah's intense sun, high humidity and exposed facades, so every unit is sized on real load not guesswork.
- 3
Select system and equipment
Based on loads and building type we choose between splits, ducted systems, central air and chiller, and specify equipment from Carrier, YORK, General, Midea, Gree and Smart Gold to suit the project.
- 4
Draw and deliver
We draw duct routes, unit positions, diffuser locations and installation heights, and deliver a complete equipment schedule ready for construction or tendering.
Calculated design or buying blind?
| Alrabih | The usual way | |
|---|---|---|
| Unit size | Based on actual load | Guessed or oversized |
| Airflow distribution | Drawing that achieves even flow | Diffusers placed at random |
| Co-ordination | Drawings before fit-out | Costly changes later |
| System type | Suited to building and budget | Whatever the shop suggests |
| Humidity and salt air | Accounted for in equipment choice | Discovered after installation |
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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Request this serviceDuct cleaning & sanitising
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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 Mahjar mixes villas with gardens, residential flats and commercial shops spread across wider plots than downtown, but its southern location means stronger solar exposure all day, especially on west and east facades. When designing here, you must account for the extra heat load from intense sun, choose units with sufficient capacity, and plan duct runs to reach every room evenly without wasting energy.
Al Mahjar lies in south Jeddah and features relatively modern residential buildings, spacious villas and strong solar exposure.
Most villas and larger flats in Al Mahjar need either central AC or multiple split units, because their wider floor areas cannot be served by a single unit.
The AC setup in Al Mahjar
- 1
Central AC for larger villas
Villas in Al Mahjar over 200 square metres typically benefit from a single central system with distributed ducts, rather than multiple separate units.
- 2
Multi-head split for mid-sized flats
Flats between 100 and 150 square metres typically need one outdoor unit with 2 or 3 indoor heads distributed across main rooms.
- 3
Design accounts for south and west facades
Solar exposure on south and west facades requires extra cooling capacity in the design to offset the external heat load.
Before the visit
Before our visit in Al Mahjar
- 1
Provide a building plan or photos
Before we visit, send us a building plan or photos of the rooms, windows and facades so we can assess solar exposure accurately.
- 2
Identify the proposed outdoor unit location
Consider the best outdoor unit location, whether on the roof, garden or balcony, away from bedrooms and main windows.
- 3
Confirm adequate power supply is available
Check your building's electrical capacity, as central AC or multiple units need separate, robust circuits.
More districts for HVAC design
Other services in Al Mahjar
FAQ
Questions about HVAC design
When is a chiller more suitable than split units?
The decision depends on the building area, number of spaces and how it is used. In large commercial and hotel buildings a chiller gives flexible control and simplifies central maintenance. In apartments and smaller villas a split or ducted system usually fits better. The calculated heat load is what determines the right choice for your building.
How does a large glazed facade affect the design?
Large glazing exposed to Jeddah's sun raises the heat load noticeably, especially on west and north-west facades. We calculate solar gain through each facade separately, and this can change the unit type selected for that room or require extra diffusers to handle the higher load.
Can you design for an existing building with no architectural drawings?
Yes. When no drawings exist we visit the site and measure every space ourselves, recording facades, glazing and how each room is used. The survey takes longer than reviewing ready drawings, but the calculations still rest on real measurements rather than estimates, which is what makes the results reliable.
Does the design include diffuser types and dampers?
The drawings specify diffuser types, positions and sizes to match ceiling height and room shape, and show where dampers are needed to balance airflow to each zone. These details matter because a diffuser in the wrong place wastes a large part of the system capacity even when the units are correctly sized.
Does duct design differ between the ground floor and upper floors?
Yes. The top floor typically carries a higher heat load because the roof is directly exposed to the sun, which affects duct sizes and the number of diffusers needed on that level. We design each floor separately based on its own calculated load and show where dampers are needed to balance airflow between floors.
My villa in Al Mahjar is large, how many AC units do I need?
The number depends on calculating the heat load for each room based on its area, windows and sun exposure, then determining whether central AC or separate units work better.
The sun is intense in the south, does that increase equipment cost?
Strong sun exposure means you need more cooling capacity, but the right size is calculated during design before purchase, so no surprises come later.
Can outdoor units be mounted on the roofs of Al Mahjar villas and flats?
Usually yes, since Al Mahjar villas and flats have sufficient roof or garden space, but the design accounts for electrical loads and copper run lengths from the outdoor unit.
How are AC ducts distributed in a large flat or villa?
We draw the duct layout before construction, set the routing through walls and ceilings, and confirm the right pipe diameter so cold air reaches every room evenly.
