Home maintenance glossary
Plain-language definitions of the terms that come up when you're dealing with home maintenance in the UAE — so you can talk to a technician with confidence and spot when something doesn't add up.
AC Service
· 26 termsAMC (Annual Maintenance Contract)
A yearly service agreement — common in the UAE for scheduled AC upkeep.
C-wire (thermostat common wire)
The 'common' wire that gives a thermostat continuous 24V power — why smart thermostats need it and what misbehaves without one.
Capacitor
A cheap part whose failure often mimics a dead compressor.
Compressor
The pump at the heart of the system — and the costliest part to replace.
Condensate drain
The line that carries away the water your AC pulls from the air — and the usual cause of ceiling leaks.
Condensate pump (& float switch)
The small pump that lifts AC condensate up and out when a unit can't drain by gravity — plus the float switch that cuts the AC off to stop an overflow.
Condenser (outdoor unit)
The outdoor box that releases your home's heat to the outside air.
Contactor (AC electrical switch)
The heavy-duty electromagnetic switch that powers the AC compressor and outdoor fan when the thermostat calls — a cheap, common wear part.
Cooling capacity (BTU & tons)
How much heat a unit can move — sized in BTU/h or 'tons'.
Delta-T (temperature split)
The temperature difference between the air (or water) going in and coming out of a cooling coil — the number that proves cooling is actually working.
DEWA
Dubai's electricity & water utility — your AC is the biggest line on its bill.
Ducted AC
A concealed central system that pushes cooled air through ceiling ducts to each room.
Evaporator coil
The cold indoor coil that actually absorbs heat and dries the air.
Gas top-up (regas)
Refilling refrigerant — only a real fix once the leak is sealed.
Hard-start kit
An add-on that gives a compressor a stronger starting kick — helps a reluctant compressor start, but can also mask one that's dying.
High-pressure switch (AC safety cut-out)
The safety switch that shuts an AC compressor off when the refrigerant pressure climbs too high — often why a unit cuts out in peak heat.
MERV rating (air-filter efficiency)
The 1–16 scale of how much fine dust and particles an AC filter actually captures — and why higher isn't always better for your system.
Plenum (AC air distribution box)
The air-distribution box on a ducted AC where conditioned air collects before the ducts — and why its size and sealing affect airflow and running cost.
Refrigerant (AC gas)
The 'gas' that carries heat around the system — R410A and older R22.
Reversing valve (heat-pump 4-way valve)
The valve that flips a heat-pump AC between cooling and heating by reversing the refrigerant flow — why most UAE units don't have one, and what a stuck one does.
SEER / EER (AC efficiency ratings)
The two numbers that tell you how efficient an AC is — EER at one hot-day condition, SEER across a whole season — and why a higher figure means a lower running cost.
Split AC
The quiet indoor-unit-plus-outdoor-condenser system found in most UAE apartments.
Static pressure (AC airflow resistance)
The resistance an AC's blower has to push air against — and why too much (a too-fine filter, choked ducts) starves cooling and freezes coils.
Superheat & subcooling (refrigerant charge check)
The two temperature measurements a technician uses to verify an AC's refrigerant charge and diagnose a leak or overcharge — the real 'is the gas right?' test.
TXV / expansion valve
The metering valve that controls how much refrigerant flows into the evaporator — the 'throttle' that sets an AC or fridge's cooling.
VRF / VRV (variable refrigerant flow)
A system that runs many indoor AC units off one outdoor unit and varies refrigerant to each — common in larger UAE villas and offices.
Water Chiller Service
· 5 termsAHU (Air Handling Unit)
A larger central air unit that conditions and distributes air for a whole zone or building — the big brother of the FCU.
BTU meter
The meter that measures the cooling energy you use on district cooling — the basis of the consumption part of your bill.
Chilled-water loop
The closed water circuit that carries cooling from the plant to every FCU in a chilled-water or district-cooled building.
Cooling tower
The rooftop unit that rejects a chiller plant's heat to the air — the district-cooling equivalent of an outdoor condenser.
FCU (Fan Coil Unit)
The in-room unit of a chilled-water/district-cooling system — the part you actually own and maintain.
Plumbing Service
· 5 termsP-trap
The U-bend under every sink and drain that blocks sewer smells from rising into your home.
PEX piping
Flexible cross-linked plastic pipe used for hot and cold water in many modern UAE homes.
Sacrificial anode (anode rod)
The 'sacrificial' metal rod inside a water heater that corrodes instead of the tank — quietly extending the heater's life.
Stopcock (main water shut-off) & isolation valves
The main valve that shuts off your home's water supply — plus the smaller isolation valves under fixtures. Know where yours is before a leak forces you to find it.
Water hammer
The loud bang in the pipes when a tap or valve shuts suddenly — and why it damages plumbing over time.
Electrical Service
· 8 termsDistribution board (DB)
The panel of breakers that splits your home's power into separate circuits — the first place to look when something trips.
Earthing (grounding)
The safety connection that gives fault current a path to ground — why it protects you from shock and how the RCD relies on it.
KNX (smart-home standard)
The open, wired smart-home standard — a control bus that reliably links lighting, blinds, AC and more across a whole villa.
MCB (miniature circuit breaker)
The switch in your board that trips to cut power when a circuit is overloaded or short-circuits.
RCD / ELCB (residual current device)
The safety device that trips in milliseconds if current leaks to earth — the one that protects you from a fatal shock.
Surge protector / SPD
A device that clamps damaging voltage spikes before they reach your electronics — at the board (whole-home) or the socket (point-of-use).
Three-phase power
A supply that delivers power on three 'phases' instead of one — used where a home or building's total electrical load is large.
Voltage drop
The loss of voltage along a cable under load — why lights dim on a big motor start and why long runs need thicker cable.
Kitchen Equipment Maintenance
· 3 termsDoor gasket (appliance seal)
The flexible seal around a fridge, freezer or oven door — a cheap part whose failure quietly wastes energy and temperature.
Extraction hood (kitchen canopy)
The canopy, filters and duct that pull grease, smoke and heat out of a kitchen — and a real fire risk if the grease isn't cleaned out.
Grease trap (grease interceptor)
The chamber that catches fats, oils and grease from a commercial kitchen's wastewater before the sewer — a Dubai Municipality requirement.
Aluminium & Glass Work
· 17 termsAnnealed glass (ordinary float glass)
Standard, untoughened glass — cheaper, but it breaks into large sharp shards, so it isn't safety glass and shouldn't be used for doors, big panes or wet areas.
Anodising (anodised aluminium)
An electrochemical finish that grows a hard, corrosion-resistant oxide layer into the aluminium itself — durable and colour-fast in the sun.
Back-painted glass
Glass with its rear face painted in any colour — the seamless, wipe-clean choice for splashbacks and feature walls.
Curtain wall (glass facade)
The aluminium-and-glass outer skin of a tower — it keeps weather out but carries no building load, and it's shared facade responsibility, not a single flat's.
Curved (bent) glass
Flat glass heated and slumped/bent over a mould to a permanent curve — available toughened or laminated, so it keeps its safety rating for curved showers, balustrades and shopfronts.
Double glazing
Two glass panes with a sealed gap between them — cuts heat and noise, and the whole sealed unit is replaceable if it fogs.
Low-E glass
Glass with an invisible metallic coating that reflects radiant heat — cutting solar heat gain in the Gulf sun.
Low-E glass (low-emissivity)
Glass with an invisible heat-reflecting coating — the single biggest glazing upgrade for cutting AC load in the UAE.
Low-iron glass (extra-clear glass)
Ultra-clear glass with the green tint removed — used where true colour and clarity matter, like pale splashbacks, shower screens and glass balustrades.
Mashrabiya (decorative screen)
The traditional Arabic latticed screen — now often laser-cut aluminium — that shades, gives privacy and adds pattern to facades, balconies and partitions.
Mullion (and transom)
The vertical bar that divides a window, door or facade into sections — a transom is the horizontal one. In aluminium systems they carry loads and hold the glass.
Patch fitting
A small metal corner clamp that grips frameless glass — the fitting that holds a frameless glass door, screen or balustrade with minimal framing.
Powder coating
A tough, baked-on dry finish for aluminium windows, railings and gates that resists the UAE sun and salt.
Spacer & desiccant (sealed-unit edge)
The edge bar that holds a double-glazed unit's panes apart and the drying agent inside it — the parts whose failure fogs your glass.
Tempered vs laminated glass
Two kinds of safety glass — tempered is heat-strengthened and shatters into blunt pebbles; laminated is bonded and holds together when broken.
Thermal break
An insulating barrier inside an aluminium frame that stops heat conducting straight through the metal.
Tilt-and-turn window
A window that does two things on one handle — tilts inward at the top for secure ventilation, or turns fully inward like a door for full opening and easy cleaning.
Painting & Gypsum Work
· 6 termsCornice (gypsum cornice / coving)
The decorative moulding that runs along the wall-to-ceiling junction — hides the joint, finishes the edge and can conceal indirect lighting.
Elastomeric paint (flexible weatherproof coating)
A thick, flexible rubber-like exterior coating that bridges hairline cracks and resists UV, heat and chalking — for exteriors that last in the UAE sun.
Gypsum board (plasterboard / drywall)
The plaster-cored board used for partition walls and false ceilings — with moisture-resistant and fire-rated grades for specific rooms.
Moisture-resistant (green) gypsum board
Plasterboard with water-repellent additives (conventionally green-faced) that resists humidity and splashes in bathrooms/kitchens — moisture-RESISTANT, not waterproof.
Primer / sealer
The prep coat that seals a surface and helps the topcoat stick, cover evenly and last — the step that makes or breaks a paint job.
Skim coat (skimming)
A thin final layer of plaster/filler that smooths a wall or ceiling to a flat, paint-ready finish.
Tile & Ceramic Service
· 6 termsCementitious waterproofing
A cement-based waterproof coating brushed onto bathroom and balcony substrates — the default wet-area method in the UAE.
Epoxy grout
A waterproof, stain- and mould-resistant resin grout for wet areas — far tougher than cement grout, but harder to apply.
Screed (floor screed)
The mortar layer over the slab that levels the floor and, in wet areas, forms the slope to the drain.
Tile levelling system
Clips and wedges that hold adjacent tiles flush while the adhesive sets — preventing lippage (uneven edges) on large-format tiles.
Tile trim (edge trim / profile)
The metal or PVC profile that finishes an exposed tile edge or external corner — protects the vulnerable edge and gives a neat line instead of a raw or mitred edge.
Waterproofing membrane
The hidden waterproof layer under the tiles and screed that actually keeps water out — not the grout or silicone.
Wood Work Service
· 3 termsMR-MDF (moisture-resistant MDF)
Moisture-resistant MDF — a treated board (usually green-tinted) that resists humidity and damp far better than standard MDF, common for UAE kitchens and wardrobes.
Plywood (incl. marine / BWP grade)
An engineered board of thin wood layers cross-bonded for strength and stability — with water-resistant grades for wet, humid areas.
Veneer (wood veneer)
A thin layer of real wood bonded to a stable engineered core — the look of solid timber with far less warping.
Apartment & Office Renovation
· 5 termsDefects-liability period (DLP)
The warranty window after handover when the contractor must fix defects in their own work, free of charge.
Fit-Out NOC
The developer or building 'no objection' letter you must get before any renovation work can start in a Dubai property.
MEP (Mechanical, Electrical, Plumbing)
The mechanical, electrical and plumbing systems of a home — the behind-the-walls work that goes in first and usually needs approval.
Provisional sum (and prime cost / PC sum)
A budgeted allowance in a renovation quote for work or items not yet fully defined — a placeholder that's reconciled to the actual cost once specified, so a quote full of them isn't really a fixed price.
Snagging
The final defect inspection of a renovation or a new handover — the punch-list of everything to fix before you sign off.