Server room in a Dubai office fit-out: cooling and approvals

Why an ordinary split unit does not work

Office air conditioning is designed for people. It holds a comfort band, it cycles on room air temperature at one sensor near a door, and it is sized on a load that assumes bodies, lights and a laptop each. A cabinet of switches and servers is a constant load with no occupancy pattern at all.

The thing that catches tenants in Dubai towers is the operating schedule, not the capacity. Fan coils fed from base build chillers or from district cooling follow the building's hours. Plenty of towers reduce or stop chilled water outside office hours and over the weekend, which is exactly the period nobody is in the room to notice the temperature climbing. Ask building management in writing whether cooling to your floor runs 24 hours. The answer changes the design.

Precision cooling is built for the duty. A CRAC unit has its own refrigerant circuit and an outdoor condenser; a CRAH unit runs a chilled water coil off the building. Both move high airflow at a small temperature difference, run continuously at close to full sensible capacity, and control humidity rather than letting it fall wherever the compressor leaves it. Most specifications hold the inlet air somewhere in the 18 to 27 degree band with relative humidity around 40 to 60 percent, following the ASHRAE recommended envelope that equipment warranties are written against. That is industry practice rather than a UAE rule, and your IT vendor's warranty conditions are the document that makes it binding.

Humidity matters in both directions. Air that is too dry builds static around people handling cards. Air that is too damp corrodes contacts, and in a Dubai summer a poorly sealed room pulls moisture in every time the door opens.

One unit means a single point of failure, so office rooms are usually built with two units alternating under a lead and lag controller, each able to carry the load alone. A portable spot cooler has one honest use, which is keeping a two rack cupboard alive while a proper unit is procured. It makes condensate, it makes noise, and it is not a design.

Working out the heat load before anyone buys a unit

Every watt the equipment draws from the socket leaves the room as heat. That is the whole calculation, and it starts from the equipment schedule rather than from the floor area. Watts per square foot rules of thumb are the main reason rooms end up undersized.

A typical office comms room runs at low single digit kilowatts per rack. Blade and compute density in a real data centre sits far above that, and the gap matters because the cooling strategy changes with it. A room with two or three light racks is a different machine from a room with a full row at eight kilowatts a cabinet.

Add what sits around the IT load: UPS and PDU losses, lighting, any transformer in the room, solar gain if one wall faces outside, and the people who will be in there during a maintenance window. Then add headroom. Ask the IT vendor what the three year plan looks like and leave spare rack positions, spare breaker ways and cooling capacity for it. Retrofitting capacity into a finished room means opening a ceiling that has already been signed off.

Airflow geometry does more in a small room than a bigger unit does. Face every rack the same way so there is a cold aisle in front and hot air returning to the unit behind. Fit blanking panels in every empty rack space and brush grommets in floor or roof cutouts, because hot air recirculating around the back of a cabinet is what actually trips equipment. Full hot and cold aisle containment earns its keep once you have a row to contain; on three cabinets, discipline about blanking panels gets you most of the way.

Put the sensors where the problem is. A wall thermostat reads a room that looks fine while the inlet of the top server runs much hotter. Measure at the air inlet of the highest device in the rack, and alarm on that.

Every cooling unit also makes water. The condensate drain needs a fall to a proper drainage point, or a pump with a high level alarm, plus leak detection under the floor. The drain route is the item most often drawn last and built worst, and a slow leak above a rack is the most expensive plumbing in the building.

Clean agent suppression and the test that proves the room

Sprinklers protect the building. They do not protect your hardware, because water finishes the job the fire started. A clean agent system floods the room volume with an agent that interrupts combustion and leaves no residue, so equipment that was not already burning can be powered back up. On Dubai projects the names you see are FM200 (HFC-227ea) and Novec 1230.

Design is by volume, not by area. The cylinder is sized on the protected envelope, and that includes the raised floor void and the ceiling void where those sit inside the protected space. Change the ceiling height after the system is designed and the quantity of agent is wrong.

Detection sits in front of it. Smoke detection is normally cross zoned so two separate detectors are needed before release, and early warning aspirating detection of the VESDA type is common in rooms where equipment downtime is the real risk. An aspirating system samples air through pipework and flags smoke long before a point detector in the ceiling reacts.

The interlocks are what the fire consultant draws and what the inspector checks. On release, the air conditioning shuts down and dampers close so the agent is not blown out of the room. Sounders and strobes operate, the manual release and the abort station work as labelled, the door holds, and the signal reaches the building's fire panel. Whether rack power drops on discharge is a decision to take with the IT vendor and write down, not an assumption.

A sealed room also needs a pressure relief vent sized for the discharge. Agent arrives fast, the room over-pressurises, and a drywall partition is the weakest element in the enclosure. Rooms have had their walls moved by their own suppression system.

Then comes the test that decides whether any of it works. The enclosure integrity test, often called a door fan test, uses a calibrated fan to measure how leaky the room is, and the software calculates how long the agent concentration will stay above design level at the protected height. Ten minutes of hold time is the figure commonly specified for clean agent rooms through the NFPA standards the UAE code references.

That test is a verdict on construction quality, which is why it belongs to the fit-out contractor as much as to the fire contractor. It is passed or failed by cable penetrations that were never fire stopped, a partition that stops at the ceiling grid instead of running to the slab, a door with a 10 mm undercut and no drop seal, a return air grille connecting the room to the corridor, and the floor void nobody sealed at the perimeter. Build for the test from the first partition track and it passes first time. Build a normal office room and the retest arrives in your handover week.

Whether your particular room must have fixed suppression is set by the UAE Fire and Life Safety Code of Practice applied to your building and occupancy by a registered fire consultant, and confirmed on the approved drawings rather than by a rule of thumb. Many landlords also require it in the fit-out manual regardless. Submissions go through a consultant and a contractor registered with Civil Defence, and that registration belongs to the company; the full Civil Defence approval sequence is set out here. Budget for the maintenance contract too, because cylinder weighing and annual inspection keep the certificate valid.

Power: dedicated circuits, UPS and the DEWA question

Rack power comes off dedicated circuits from the board, labelled, with nothing else on them. A server room sharing a circuit with the cleaner's socket outside the door is a story every IT manager in Dubai can tell.

For protection, racks want an online double conversion UPS rather than a line interactive unit, sized for the load with headroom and with a maintenance bypass so a battery change is not an outage. Office rooms are normally sized for minutes rather than hours: enough to ride through a dip and shut systems down cleanly. Anything longer is a generator conversation, and in a leased tower that conversation is short. The base build generator usually carries life safety, lifts and landlord services, so ask what is on the essential supply and whether the floor's essential board has spare capacity before promising anyone a generator feed.

The cooling is the larger electrical ask, and it decides your DEWA route. A DX precision unit is a continuous electrical load that you own, with a condenser that has to go somewhere outside. A chilled water unit draws far less power and spends the building's chilled water allocation instead. On district cooling, extra capacity is a commercial discussion with Empower or Emicool under the building's allocation, not a DEWA application at all.

Where the load does grow, the route depends on the size of the change. A meter moving into your company name is an activation. New or altered boards with the same demand go through DEWA's fit-out power connection, submitted by an enrolled contractor. Demand beyond what the unit was built to give becomes a load increase, and a change to the supply itself becomes a chargeable network modification priced by estimate before anything is built. DEWA's regulations also require provision for a substation within the building or plot once total connected load passes 400 kW, and allow it to be required below that. Which DEWA route applies, and how a load increase is assembled, is covered in detail here.

The electrical package has its own quiet omissions. A check meter on the server room supply, if you want the load visible for recharge or monitoring, has to be in the design rather than added later. And earthing: a clean earth for the comms equipment, bonding for racks and raised floor pedestals, and surge protection at the board feeding the room.

Fitting the server room into the building you actually leased

The constraint is rarely the room. It is the building around it.

If you go DX, the condenser needs a location, a pipe route and the landlord's approval to use it. Facade, balcony, roof or plant deck, all of which belong to someone else in a tower. We have seen a server room design change direction entirely in week one because there was nowhere legal to put a condenser, and finding that out in week one is the cheap version of that discovery.

If you go chilled water, you need an allocation and you need it around the clock. Get the figure and the operating hours from building management in writing, because a CRAH unit on a chilled water loop that stops at 7pm is just an expensive cabinet.

A raised floor helps with cabling and underfloor air, and it brings its own consequences. The void counts in the suppression volume, it needs smoke detection, and on a low Cat A floor the extra height can break your clear ceiling height or force a ramp at the door. Many offices now run power and data overhead on containment and skip the floor, which also removes a leak path for condensate.

Keep the room's air to itself. A shared return grille into the corridor undermines the cooling and will fail the integrity test. Where ducts cross the partition, they need dampers that close on alarm.

Location deserves ten minutes of thought at concept stage. Next to a meeting room guarantees noise complaints. On an external wall adds solar gain all afternoon. Directly below a pantry or a toilet on the floor above adds a water risk you cannot design away. And the room needs card access, fire rated construction where the drawings call for it, and a door that swings in the escape direction. Concentrated loads from UPS batteries and loaded racks are worth a structural check on older slabs or anywhere near a mezzanine.

Approvals, inspections and the order they run in

The architectural work is part of your main fit-out submission, approved by Dubai Municipality on the mainland or by the relevant free zone or master developer authority where the unit sits. The new partition, the door, the floor and any change to the ceiling all live in that file. Our office fit-out scope covers how that submission is put together.

The fire package runs in parallel, which is the point of filing them together. The registered fire consultant draws detection, suppression, interlocks and signage; Civil Defence reviews; a layout change during construction means a resubmission before installation, not an explanation at inspection.

The DEWA application follows the load, and on anything beyond an activation it belongs on the critical path from week one.

Across all of it sits the landlord. The fit-out manual approval, a method statement for any work in the risers or on the roof, access and testing windows, and a separate consent for a condenser on the building. Mall and tower fit-out managers often issue their own clearance before your hoarding comes down.

At the end, the inspections stack up in a fixed order, and each one generates comments that become snag items. The suppression system is commissioned and the cause and effect matrix witnessed. The enclosure integrity test is run and the report issued. Civil Defence inspects against the approved drawings and issues the completion certificate. The electrical installation is inspected before the permanent meter is released. Then the building completion file closes.

Collect the paperwork as it happens: the fire contractor's commissioning records, agent cylinder certificates, the integrity test report, the precision AC commissioning sheet with measured airflow and setpoints, electrical test results, and the O&M file. A document pack assembled the week after handover is a pack assembled from memory.

Who does what: fit-out contractor, MEP engineer, IT vendor

Most server room disputes are scope disputes, so write the boundary into the contract.

Acceptance splits the same way. Civil Defence issues the completion certificate for the fire system. The cabling contractor issues the structured cabling test results. Your handover signature covers the room and its services against the approved drawings and the commissioning records. Nobody should be signing anything before those records exist.

What settles most of the rest is commercial rather than technical: who buys the UPS, who holds the suppression maintenance contract after handover, who owns the equipment schedule and by what date, and who pays for the integrity test and a retest if it fails.

• The fit-out contractor builds the room and owns the programme. Partition to slab with sealant, fire stopping at every penetration, door and ironmongery, floor finish or raised floor, containment, coordination of the trades, and the submissions through the appointed consultants. We also carry the integrity test as a build obligation, because the leaks are ours.
• The MEP engineer designs. Heat load calculation from the equipment schedule, unit selection, pipework and condensate design, condenser location, load schedule and single line diagram, and the stamped drawings that go to the authorities. Where that scope starts and stops is set out in our note on what an MEP contractor actually covers in a fit-out.
• The fire consultant and fire contractor, both registered with Civil Defence, own the suppression design, the submission, the installation and the commissioning. A fit-out contractor without that registration subcontracts it, and the registered party's name goes on the file. Ask who that is at tender stage.
• The IT vendor supplies racks, servers, switches, structured cabling and PDUs, usually the UPS, and the equipment schedule everything else is calculated from. That schedule is the single most frequently late document on these rooms.

How we approach it on a tower floor

On the offices we delivered at Platinum Tower in JLT for Solvu Solutions and AD Tyres, the comms room questions started with building management rather than with the drawings: the chilled water position and operating hours for the floor, whether the base build fire panel would accept a new interface, and the access and testing windows we would be allowed. That order is deliberate. Everything inside the room is ours to solve. Everything outside it is a permission, and permissions set the programme.

Cost works the same way. We will not publish a figure for a server room, because the honest answer depends on room volume, the agent quantity that volume demands, whether the cooling is DX or chilled water, where a condenser can physically go, and the load your equipment schedule carries. Send the floor plan and your IT equipment schedule on +971 56 508 0888 and that becomes a real number instead of a range, with the cooling route, the suppression scope and the approval sequence written into the programme. If you are still comparing contractors, start with a costed estimate.