The one-stop HVAC library for architects and interior designers

01 · Every Daikin VRV indoor unit, and where it fits

How much ceiling each one needs, its size in tons, its dimensions, when to use it and its limits. Pick a unit.

Hidden in the ceiling

Ducted units: only the grilles show.

Slim duct (low static) (Daikin FXDQ): 0.6–2.0 TR

• Ceiling to plan for: 11–12 in (280–305 mm)
• Unit height: 200 mm
• Dimensions (H × W × D): 200 × 700 × 620 mm (0.6–1.0 TR); 200 × 900 × 620 mm (1.3–1.6 TR); 200 × 1,100 × 620 mm (2.0 TR)
• Sizes: 0.6, 0.8, 1.0, 1.3, 1.6, 2.0 TR
• What shows in the room: Only the grilles
• Best for: Bedrooms, Hotel rooms, Cabins

Use it when:

• Quiet rooms: one of the quietest units, 29–36 dB(A)
• Low false ceilings: the unit is only 200 mm high
• No long ducts: a short plenum and grilles right beside the unit

Limitations:

• 2 TR at most
• Low static pressure: short plenums only, no long duct runs
• Gentle air throw, so a big room takes longer to cool

• Static pressure: 10–44 Pa (low)
• Sound: 29–36 dB(A)
• Airflow: 6.4–16.5 m³/min
• Drain pump: Standard, lifts 750 mm
• Weight: 23–31 kg
• Note: Return air from below is 5 dB(A) louder than from the back

Mid static duct (Daikin FXMQ-A): 1.3–3.2 TR

• Ceiling to plan for: 14–15 in (355–380 mm), plus ducts
• Unit height: 300 mm
• Dimensions (H × W × D): 300 × 700 × 700 mm; 300 × 1,000 × 700 mm (larger sizes)
• Sizes: 1.3, 1.6, 2.0, 2.6, 3.2 TR
• What shows in the room: Only the grilles
• Best for: Living rooms, Large bedrooms, Cabins

Use it when:

• A short duct to two or three grilles
• Linear slot diffusers along a window or wall
• More push than the slim duct, for bigger rooms

Limitations:

• 300 mm unit, plus the depth of the ducts
• 37–44 dB(A): keep it away from bed heads
• Ducts and grilles need designing

• Static pressure: 30–60 Pa (medium)
• Sound: 37–44 dB(A)
• Airflow: 12–34 m³/min
• Drain pump: Standard, lifts 700 mm
• Weight: 27–36 kg

High static duct (Daikin FXMQ-P): 0.6–4.6 TR

• Ceiling to plan for: 14–15 in (355–380 mm), plus ducts
• Unit height: 300 mm
• Dimensions (H × W × D): 300 × 700 × 700 mm (smaller sizes); 300 × 1,000–1,400 × 700 mm (larger sizes)
• Sizes: 0.6, 0.8, 1.0, 1.3, 1.6, 2.0, 2.6, 3.2, 4.0, 4.6 TR
• What shows in the room: Only the grilles
• Best for: Open offices, Showrooms, Halls

Use it when:

• Long duct runs and many grilles
• The unit can sit over a passage or toilet, away from the room
• Fresh air can be mixed in

Limitations:

• Needs a proper duct design: sizes, dampers, insulation
• A deeper ceiling wherever ducts cross
• Keep the unit away from quiet rooms

• Static pressure: 30–200 Pa by size (high)
• Sound: 29–46 dB(A)
• Airflow: Up to 46 m³/min
• Drain pump: Standard, lifts 700 mm
• Weight: 27–46 kg

Cassettes

A grille set into the false ceiling.

1-way cassette (corner) (Daikin FXKQ): 1.0–2.0 TR

• Ceiling to plan for: 8–9 in (205–230 mm)
• Unit height: 175 mm (145 mm unit + 30 mm clearance (Daikin))
• Dimensions (H × W × D): 175 mm high, with clearance; Panel 1,390 × 595 mm, 41 mm thick
• Sizes: 1.0, 1.3, 1.6, 2.0 TR
• What shows in the room: A slim panel along the wall
• Best for: Bedrooms, Hotel rooms, Cabins

Use it when:

• The lowest ceiling of any ceiling unit: it finishes at 8–9 inches
• A seamless fit along a wall or in a corner
• Bulkheads, narrow ceilings and window lines

Limitations:

• 2 TR at most
• Blows one way only: place it to throw across the room
• Leave 3 inches (75 mm) behind it, from the wall

• Back gap: 3 in (75 mm) between the back of the unit and the wall
• Spacers: 25 mm each, up to 75 mm: for ceilings as shallow as 100 mm
• Panel: White or silver

600 × 600 cassette (Daikin FXZQ): 0.6–1.6 TR

• Ceiling to plan for: 13–14 in (330–355 mm)
• Unit height: 260 mm
• Dimensions (H × W × D): 260 × 575 × 575 mm; Fits one 600 × 600 ceiling tile
• Sizes: 0.6, 0.8, 1.0, 1.3, 1.6 TR
• What shows in the room: Flush in one ceiling tile
• Best for: Offices, Meeting rooms, Shops

Use it when:

• Grid ceilings: fits one 600 × 600 tile, only 8 mm below it
• Lights, speakers and sprinklers can sit in the next tile
• Air in four directions from the centre of a room

Limitations:

• 1.6 TR at most
• Needs 13–14 inches above the ceiling
• The grille shows in the ceiling

• Sound: 25.5–43 dB(A)
• Airflow: 6.5–14.5 m³/min
• Weight: 15.5–18.5 kg
• Options: Presence and floor sensor; fresh-air kit

Round flow cassette (Daikin FXFSQ): 0.8–4.6 TR

• Ceiling to plan for: 13–15 in (330–380 mm)
• Unit height: 256–298 mm
• Dimensions (H × W × D): 256 or 298 × 840 × 840 mm, by size; Panel 950 × 950 mm
• Sizes: 0.8, 1.0, 1.3, 1.6, 2.0, 2.6, 3.2, 4.0, 4.6 TR
• What shows in the room: A 950 × 950 mm panel
• Best for: Open offices, Showrooms, Large living rooms

Use it when:

• Large rooms: air all round, 360°, without draughts
• Optional sensor panel: senses people and the floor temperature
• Optional auto grille lowers the filter: no ladder to clean it

Limitations:

• A large panel to work into the ceiling design
• Needs 13–15 inches above the ceiling
• A ceiling cut-out and access for service

• Panel depth: Standard 50 mm, designer 97 mm, auto grille 105 mm
• Sound: 27–46 dB(A)
• Airflow: 10–35.5 m³/min
• Sensor: Senses people up to about 8.5 m across at a 2.7 m ceiling

2-way cassette (Daikin FXCQ): 0.8–4.0 TR

• Ceiling to plan for: 15–16 in (380–405 mm)
• Unit height: 305 mm
• Dimensions (H × W × D): 305 × 775–1,445 × 620 mm; Panel 1,070–1,740 × 700 mm, 55 mm thick
• Sizes: 0.8, 1.0, 1.3, 1.6, 2.0, 2.6, 4.0 TR
• What shows in the room: A long, narrow panel
• Best for: Corridors, Long rooms, Glass façades

Use it when:

• Long, narrow rooms: blows to both sides
• Along a window line or a glass façade
• Its drain pump lifts water 850 mm

Limitations:

• The deepest cassette: 305 mm unit
• A long panel, up to 1,740 mm, to line up with the ceiling

• Sound: 29–46 dB(A)
• Airflow: Up to 32 m³/min
• Drain pump: Standard, lifts 850 mm
• Filter: Long-life: cleaned once a year

No false ceiling needed

Under the slab or on the wall.

Ceiling suspended (Daikin FXHQ): 1.0–4.4 TR

• Ceiling to plan for: No false ceiling needed
• Unit height: 195–235 mm
• Dimensions (H × W × D): 195 × 960–1,400 × 680 mm; 235 × 1,590 × 690 mm (largest)
• Sizes: 1.0, 2.0, 3.2, 4.0, 4.4 TR
• What shows in the room: A slim unit under the slab
• Best for: Shops, Restaurants, High ceilings

Use it when:

• Exposed slabs with no false ceiling
• High ceilings, up to 4.3 m: it throws air far
• Quick retrofits in finished spaces

Limitations:

• The whole unit is on show
• A wide unit: 960–1,590 mm

• Sound: 31–48 dB(A)
• Airflow: 10–36 m³/min
• Weight: 24–41 kg

4-way ceiling suspended (Daikin FXUQ): 2.3–3.2 TR

• Ceiling to plan for: No false ceiling needed
• Unit height: 198 mm
• Dimensions (H × W × D): 198 × 950 × 950 mm
• Sizes: 2.3, 3.2 TR
• What shows in the room: A 950 mm square unit with round corners
• Best for: Cafés, Showrooms, Exposed ceilings

Use it when:

• The look of a cassette, with no false ceiling
• Air in 2, 3 or 4 directions, each flap set on its own
• Industrial and exposed ceilings

Limitations:

• Only two sizes
• The unit is on show

• Sound: 36–47 dB(A)
• Drain pump: Standard, lifts 600 mm

Wall mounted (Daikin FXAQ): 0.6–3.1 TR

• Ceiling to plan for: No false ceiling needed
• Unit height: 298–325 mm
• Dimensions (H × W × D): 298 × 929 × 258 mm (0.6–2.0 TR); 325 × 1,060–1,220 × 278 mm (2.5–3.1 TR)
• Sizes: 0.6, 0.8, 1.0, 1.3, 1.6, 2.0, 2.5, 2.9, 3.1 TR
• What shows in the room: The unit on the wall
• Best for: Bedrooms, Small offices, Retrofits

Use it when:

• No false ceiling at all
• The simplest unit to fit and to service
• Retrofits in finished rooms

Limitations:

• On show on the wall
• The drain needs a route out of the room
• The larger sizes are louder, up to about 55 dB(A)

• Sound: 31–47 dB(A) up to 2 TR; 44–55 dB(A) above
• Weight: 13–20 kg
• Panel: Flat: wipes clean in one pass

On the floor

Under windows and along glass.

Floor standing (Daikin FXLQ): 1.0–2.0 TR

• Ceiling to plan for: No false ceiling needed
• Unit height: 600 mm
• Dimensions (H × W × D): 600 × 1,140 × 222 mm (1.0 TR); 600 × 1,420 × 222 mm (1.6–2.0 TR)
• Sizes: 1.0, 1.6, 2.0 TR
• What shows in the room: A low unit against the wall
• Best for: Under windows, Glass façades, Double-height rooms

Use it when:

• Under a window or along glass
• Rooms where neither the ceiling nor the wall can take a unit
• Winter heating: warm air from low down

Limitations:

• 2 TR at most
• Takes floor and wall space

• Sound: 32–40 dB(A)
• Airflow: 6–16 m³/min
• Weight: 30–36 kg
• Also: Can be hung on the wall, for easier cleaning

Concealed floor standing (Daikin FXNQ): 1.0–2.0 TR

• Ceiling to plan for: A box at least 220 mm (9 in) deep
• Unit height: 610 mm
• Dimensions (H × W × D): 610 × 1,070 × 220 mm (1.0 TR); 610 × 1,350 × 220 mm (1.6–2.0 TR)
• Sizes: 1.0, 1.6, 2.0 TR
• What shows in the room: Only the grilles in the boxing
• Best for: Luxury living, Glass façades, Window seats

Use it when:

• Hidden in a window seat or a skirting box
• Glass façades with no wall or ceiling to use
• Warm air from low down in winter

Limitations:

• 2 TR at most
• Needs a box at least 220 mm deep, with grilles and an access panel

• Sound: 32–40 dB(A)
• Weight: 23–27 kg
• Pipes: Connect from below

Big spaces and spot cooling

Halls, auditoriums, single spots.

Large duct (Daikin FXMQ-N): 5.5–8.0 TR

• Ceiling to plan for: 20–21 in (510–535 mm), plus ducts
• Unit height: 440 mm
• Dimensions (H × W × D): 440 × 1,190–1,490 × 1,090 mm
• Sizes: 5.5, 6.4, 8.0 TR
• What shows in the room: Only the grilles
• Best for: Halls, Banquets, Large shops

Use it when:

• One big space on one unit
• Long duct runs with many grilles

Limitations:

• A 440 mm unit: the deepest ceiling of all
• Heavy, 110–130 kg: hung from the slab on proper anchors
• Needs access for service

• Weight: 110–130 kg

Floor standing duct (AHU type) (Daikin FXVQ): 4.0–15.9 TR

• Ceiling to plan for: A small AHU room, ducted to the space
• Unit height: —
• Dimensions (H × W × D): Set by size: we give the room size at design stage
• Sizes: 4.0, 6.4, 8.0, 12.8, 15.9 TR
• What shows in the room: Only the grilles
• Best for: Auditoriums, Banquets, Factories

Use it when:

• Very large spaces from one unit, with ducts
• Runs on all fresh air, or fresh air mixed with return air

Limitations:

• Needs its own room and 3-phase power
• 52–66 dB(A): needs acoustic treatment near quiet spaces

• Static pressure: 152–420 Pa
• Airflow: 43–172 m³/min
• Power: 3-phase, 380–415 V
• Drive: Belt drive, long-life filter

Spot cooler (multi cube) (Daikin FXPQ): 0.8 TR

• Ceiling to plan for: No false ceiling needed
• Unit height: 455 mm
• Dimensions (H × W × D): 455 × 555 × 470 mm
• Sizes: 0.8 TR
• What shows in the room: A box on a stand, or hung
• Best for: Workstations, Single spots

Use it when:

• Spot cooling where a room unit cannot go
• Rests on a stand or hangs from the slab

Limitations:

• One size only, 0.8 TR
• 51 dB(A): louder than room units

• Sound: 51 dB(A)
• Airflow: 11–13.5 m³/min
• Weight: 30 kg

Ceiling to plan for is Citi Cool site practice: Daikin’s ceiling figure (or the unit height plus 30 mm where Daikin gives none) plus 1 to 2 inches, so the unit can be serviced later. Add the depth of any ducts or beams crossing below. Sizes, dimensions and specifications from Daikin’s VRV Alpha catalogue (the 4-way ceiling suspended unit’s cooling from Daikin’s data for the same models). Tons are Daikin’s rated cooling in Btu/h divided by 12,000. All 15 connect to Daikin VRV Alpha; VRV Home takes ducted and wall units.

02 · How low can the ceiling go?

A unit never finishes at its bare height. The ceiling has to take the unit, room to service it later, the drain, and anything that crosses below. The 1-way cassette is 175 mm, but plan for 8–9 inches. A slim duct is 200 mm, but plan for 11–12 inches.

How low can the finished ceiling be? The National Building Code of India 2016 asks for 2.75 m in habitable rooms, and allows 2.4 m to the false ceiling or duct in air-conditioned rooms. Local bye-laws may differ, so check them for the project.

An example: 10 ft (3,050 mm) floor to slab with a slim duct (11–12 in) leaves about 2,745–2,770 mm clear: comfortably above 2.4 m. A builder floor with 9 ft (2,745 mm) to the slab and the same unit leaves 2,440–2,465 mm: just enough. A 1-way cassette (8–9 in) on that floor keeps 2,515–2,540 mm.

• The lowest ceiling of any ceiling unit is the 1-way cassette: 8–9 inches, with 3 inches left at the back, from the wall.
• Drop the ceiling only over a passage, toilet lobby or wardrobe, put the ducted unit there, and throw air into the room through a side grille. The room ceiling stays high.
• No room for any of these? A wall-mounted or ceiling-suspended unit needs no false ceiling at all.
• Leave an access panel under every ducted unit and cassette, for the filter, the drain pump and the electrical box.
• A gravity drain at the unit’s level needs 10 mm of fall for every metre (Daikin asks for at least 1:100). Most ceiling units have a drain pump, which lifts the water first.

Ceiling depth checker

A free tool on this page: pick the indoor unit, enter the floor-to-slab height, any gravity drain at the unit's level and anything crossing below. It gives the ceiling depth with room to service the unit, the clear room height, and checks it against NBC 2016.

03 · How much space the pipes need, and how to finish them

Each indoor unit gets two copper pipes, liquid and gas. Each is insulated on its own, then the two are laid side by side and taped together with the communication cable. To one indoor unit the pair finishes at about 3¼ to 3¾ inches wide and 2 to 2¼ inches deep. The drain runs on its own.

The pipe pair to an indoor unit of 2.0 to 4.6 TR: liquid 9.5 mm with 13 mm insulation and gas 15.9 mm with 19 mm insulation, taped together with the communication cable.

Insulation: 13 mm and 19 mm. We insulate every liquid pipe with 13 mm and every gas pipe with 19 mm closed-cell insulation: our standard on every project. The gas pipe carries hot gas when the system heats, so its insulation must take 120 °C (Daikin).

Finished size: each pipe plus its insulation on both sides, the two side by side. Pipe sizes from Daikin: indoor unit connections from the VRV Alpha catalogue, the 12 HP example from Daikin’s RXYQ installation manual. Main pipes grow with the size of the system; we give the sizes for yours.

The drain runs on its own, and it eats ceiling depth. Daikin’s drain connection is VP20 (26 mm outside) on the slim duct, the 1-way cassette and the ceiling suspended unit, and VP25 on the round flow cassette. A drain falls 10 mm for every metre (Daikin: at least 1:100), so a 10 m run drops 100 mm. Keep drain runs short, or let the unit’s drain pump lift the water first: 750 mm on the slim duct, 700 mm on the mid and high static ducts, 850 mm on the 2-way cassette.

Finishing the pipes

Above the false ceiling

Space: The pipe pair, as above. Finish: None: it is hidden. Watch out: Pipes under beams eat ceiling depth. Plan sleeves through beams before they are cast, with the structural engineer.

In a wall chase

Space: The pipe pair, and the drain. Finish: Mesh and plaster over. Watch out: Never squeeze the insulation thin to fit a chase: it sweats in the monsoon. Pressure-test before the chase is closed.

Boxed on a wall or ceiling

Space: The pipe pair, and the drain. Finish: Gypsum or board box, painted. Watch out: Leave a removable panel wherever there are joints.

Outdoors: terrace and façade

Space: The pipe pair in a covered tray or under cladding. Finish: Painted to match the building. Watch out: Sun cracks bare insulation, and cracked insulation drips. Never leave it open to the sky.

Sleeves through walls and slabs. One size bigger than the insulated pipe, sloping outward, and sealed once the pipes are in.

Pipe sizes to each indoor unit

Daikin VRV indoor unit connections, by Daikin’s capacity groups (VRV Alpha catalogue and RXYQ installation manual).

How far the pipes can run

Daikin VRV Alpha catalogue and RXYQ installation manual. Split ACs are much shorter (Daikin India product pages): 1.0 TR inverter splits allow 15 m of pipe and 12 m of height; 1.5 TR 20–25 m and 16–20 m; 2.0 TR up to 30 m and 20 m, by model.

04 · What a perfect VRV installation looks like

Most VRV problems start where nobody looks once the ceiling closes. These are Daikin’s own rules, plus our site standards. We follow all twelve on every job, and you can ask any installer to show you them.

Pipework

1. The right copper. Seamless, phosphorus-deoxidised copper: soft up to 15.9 mm, half-hard from 19.1 mm, with walls 0.80–1.43 mm thick by size, made for 40 bar. (Daikin rule)
2. Brazed under nitrogen, ends sealed. Nitrogen flows through the pipe while it is brazed (0.02 MPa), so no black scale forms inside to block valves. Open ends are pinched or taped until they are joined. (Daikin rule)
3. REFNET joints placed right. Only Daikin REFNET joints, branching horizontally or vertically, within 30° of level. Headers lie level, with no branch after a header. At the outdoor units, 500 mm of straight pipe before the joint. (Daikin rule)
4. Supported, not hung loose. Pipes clamped on proper supports, over the insulation without crushing it. Never tied to ducts or to the ceiling frame. (Our standard)

Insulation

5. Insulation: 13 mm and 19 mm, no gaps. Liquid and gas pipes insulated separately: 13 mm on the liquid pipe and 19 mm on the gas pipe (our standard). The gas pipe’s insulation must take 120 °C, every seam is taped, and REFNET joints are wrapped in the kit’s own insulation (Daikin). (Daikin rule and our standard)
6. Protected from the sun. Outdoors, insulation runs in a covered tray or under cladding. Sun cracks bare insulation, and cracked insulation sweats and drips. (Our standard)

Testing

7. 40 bar for 24 hours. A nitrogen pressure test at 4.0 MPa (40 bar), held for 24 hours with no drop, and written down. (Daikin rule)
8. A deep vacuum. Down to −100.7 kPa (5 Torr) for at least 2 hours, then held for 1 hour with no rise. This boils off any moisture inside. (Daikin rule)
9. Refrigerant weighed and labelled. Extra refrigerant worked out from the liquid pipe lengths, weighed in, and written on the unit’s label. VRV Alpha can also charge itself automatically. (Daikin rule)

Drains, wiring, outdoor unit, handover

10. Drains and wiring done right. Drains fall at least 1:100. Communication wiring stays at least 50 mm from power wiring. (Daikin rule)
11. The outdoor unit on a proper base. At least 150 mm high, carrying the unit along its length, not just at the corners. Bolted down with four M12 bolts, with drainage around it and its service space kept clear. (Daikin rule)
12. Handed over with records. Test-run readings, the pressure and vacuum records, the refrigerant charge and an as-built drawing, for your client’s file. (Our standard)

Daikin rules from Daikin’s VRV installation manuals (RXYQ series) and the VRV Alpha catalogue. Our standards are the way we build on every site.

05 · Outdoor units: where they can go

The outdoor unit works hardest on the hottest Delhi afternoons. Put it in a tight recess, a closed shaft or behind louvres that do not breathe, and its own hot air comes back into it. It runs hotter than the weather and loses capacity. We size ACs taking about 5% off for every °C above a unit’s rating, so a few degrees of trapped heat matter.

• Give the unit open air at the front and above. Louvres must be open enough for hot air to leave.
• Clearances differ by model. We take them from the selected unit’s installation manual and mark them on your drawing.
• On a terrace, set units on a raised base on a waterproofed slab, away from bedroom windows.
• On balconies and ledges, plan safe access for service. Nobody should have to hang outside to clean a coil.
• VRV outdoor units are large and heavy. Plan the slab or beam they sit on, and the route to lift them up.
• Keep outdoor units away from your client’s bedrooms and the neighbours’ windows.

Daikin’s rules for the base. At least 150 mm high, carrying the unit along its length and not only at the corners, bolted down with four M12 bolts, with a drainage channel around it. On a roof, the base must be strong and waterproofed.

06 · Free tools and guides

HVAC coordination checklist

At concept

• System chosen: splits, VRV or ducted
• Indoor unit for each room, from the indoor unit corner
• Outdoor unit locations agreed, with open air around them
• Riser shaft and pipe routes for every system, with access on every floor

Ceiling design

• Ceiling depth with room to service: 8–9 in for a 1-way cassette, 11–12 in for a slim duct, 14–15 in plus ducts for a mid or high static duct
• 3 in left behind every 1-way cassette, from the wall
• Access panel under every ducted unit and cassette
• Supply and return grilles on the RCP

Before plaster

• Pipe routes and sleeves marked; chases sized for the pipe pair and the drain
• Drain routes with 1:100 fall, or a drain pump
• Power points for indoor and outdoor units, isolators near outdoor units
• Wired remote positions beside the light switches

Before the false ceiling closes

• Pressure test at 40 bar held for 24 hours, and recorded
• Insulation complete: 13 mm on liquid, 19 mm on gas, seams taped, REFNET joints covered
• Pipes clamped on supports, not tied to ducts or the ceiling frame
• Ducts and plenums insulated

Outdoors

• Outdoor units on a base at least 150 mm high, bolted down
• Outdoor pipes in a covered tray or under cladding
• Service space kept clear

Handover

• System tested and commissioned, readings recorded
• Refrigerant charge on the unit label
• As-built drawing, warranty and service contacts handed over
• Client shown the controls

Our heat load report

A sample of our report for a Delhi project. Values are hidden: the method and our design data are our own. You get the full report for your project.

• Cover and design conditions
• Terms and basis of design
• Methodology
• Infiltration, floors, partitions, allowances
• Cooling load summary and equipment selection
• Room-by-room heat load estimate
• Design basis and sources
• U-value derivations
• Revision ladder

Guides