Dimensions and installation requirements of IVAR SL, SLI and SLS fancoils
Dimensions and installation requirements of IVAR SL, SLI and SLS fancoils
When a designer or installer first reaches for IVAR SL, SLI or SLS fancoils, the most common first question is not about performance or type of control – it is simple: "Will it fit there?" And immediately after it comes: "What do I need to ensure before installation?" This topic may seem boring at first glance, but in practice it is precisely the neglect of dimensional and installation requirements that is behind most complaints, rework and dissatisfied customers.
In this article we will go into depth on everything you need to know about physical dimensions, construction cutouts, installation spaces, access requirements and related technical details for IVAR fancoils in three basic configurations – ceiling-mounted SL, ducted (ductable) SLI and floor-mounted SLS. Numbers, diagrams, examples from practice and tips that will save you time and nerves.
Three series, three installation philosophies
Before we get into specific numbers, it is important to understand the basic structural difference between these series, as it directly affects installation requirements.
IVAR.SL is a cassette/ceiling-mounted fancoil mainly intended for installation above a ceiling or directly on the ceiling. Air is drawn from above (or from the side) and distributed through outlets. It is the most common type in office spaces, hotels and retail stores.
IVAR.SLI is a ducted (ductable) fancoil – a short "ductable" unit. Air is supplied and discharged through ducts, the unit itself is completely hidden in the ceiling or in a technical shaft. It is used where it is necessary to distribute air to several rooms or where interior design does not allow any visible equipment.
IVAR.SLS is a floor/parapet-mounted fancoil. It is installed on the floor or under the parapet, air circulates from below upwards or forward. Ideal for renovations where it is not possible (or desirable) to interfere with the ceiling, and for spaces with large glazed facades.
Each of these types has different requirements for construction cutouts, access to the equipment, condensate drainage and media connection. Let's look at each one separately.
IVAR.SL – ceiling-mounted fancoil: dimensions and space requirements
IVAR.SL fancoils are produced in several performance sizes, each of which corresponds to different physical dimensions. The manufacturer marks them with a number (e.g. 200, 300, 400, 600, 800, 1000, 1200), which generally corresponds to the nominal capacity in tens of watts at cooling.
Typical dimensions of ceiling-mounted IVAR.SL units are as follows (all values in mm, approximate – always check the current technical sheet for the specific model):
| Model | Width (mm) | Depth (mm) | Height (mm) | Weight (kg) |
|---|---|---|---|---|
| SL 200 | 620 | 300 | 220 | 11 |
| SL 300 | 820 | 300 | 220 | 13 |
| SL 400 | 1020 | 300 | 220 | 15 |
| SL 600 | 1220 | 340 | 240 | 18 |
| SL 800 | 1420 | 340 | 240 | 20 |
| SL 1200 | 1820 | 340 | 240 | 25 |
From the table, several important practical conclusions can be drawn. The depth of the unit (dimension perpendicular from the ceiling downward) is 220–240 mm for most models. This means that if you have a ceiling cavity depth of only 180 mm, you simply cannot fit an SL unit. I have encountered this problem in practice, for example during the renovation of office spaces in panel buildings – the original ceiling cavity had only 160 mm of free space, so we had to lower the entire ceiling cavity by 8 cm, and the client lost that in ceiling height.
The width of the unit increases proportionally with the capacity, and for the largest models it exceeds 1.8 m. This is a key parameter when designing the layout in long corridors or when combining multiple units. Leave at least 30 cm of free space between two adjacent SL units for access to the installation connections and the service opening.
Service Access Space for IVAR.SL
One of the most common mistakes I see on customer sites is insufficient planning of the service space. A fan coil is a device that requires regular maintenance – at least once a year, the filter must be cleaned, the condensate tray must be checked, and the electrical connections must be inspected. If there is no access to the unit, it becomes a ticking time bomb.
For IVAR.SL, the following minimum service spaces apply:
- Under the unit: free access of at least 400 mm (for removing the filter and accessing the fan)
- On the media connection side: at least 200 mm from the wall or other obstacle for connecting flexible hoses and ball valves
- Service opening in the ceiling cavity: at least 600 × 400 mm, always place it on the connection side, ideally also on the fan side
- Condensate drain: route with a minimum slope of 1% from the unit, without a siphon installed immediately after the outlet from the tray, back suction is a risk
IVAR.SLI – ducted fan coil: dimensions, cutouts and piping requirements
The ducted fan coil IVAR.SLI is the one of the three that places the highest demands on the installer in terms of precise planning. The unit itself is hidden, but every millimetre of error in the dimensions of the ducting system will manifest either as noise, reduced performance, or – worst of all – condensation in places where it should not be.
Typical dimensions of the SLI unit itself are slightly more compact than the SL, as it does not have a cassette with output louvers:
| SLI Model | Width (mm) | Depth (mm) | Height (mm) | Inlet Flange |
|---|---|---|---|---|
| SLI 200 | 550 | 270 | 195 | 250×150 |
| SLI 300 | 750 | 270 | 195 | 300×150 |
| SLI 400 | 950 | 270 | 195 | 350×200 |
| SLI 600 | 1150 | 310 | 220 | 400×200 |
| SLI 800 | 1350 | 310 | 220 | 450×250 |
Flange connection of the duct system – what to note
The flange of the suction inlet is a key dimension that the designer must capture right from the first phase of the design. If you later find out that the HVAC duct has different dimensions, you will have to make a reduction – and every reduction increases pressure losses and potentially generates noise. For IVAR.SLI 400, the suction flange is 350 × 200 mm. For model 600, it is 400 × 200 mm.
For the suction inlet, additional accessories are also available – for example, suction kit for IVAR.SLI DC 400, which facilitates the connection of filtered air from the ceiling space without the need for an HVAC duct distribution. This kit includes a frame, filter, and gasket – it is advantageous especially when the air quality in the ceiling space is sufficient and there is no need to bring air from the shaft.
Analogously, for model SLI 600, the inlet grid for IVAR.SLI DC 600 is available, which allows direct suction through an opening in the ceiling with decorative covering.
Minimum ceiling space for SLI
The height of the SLI unit is 195–220 mm, but you must add:
- Suspended consoles or profiles: 30–50 mm
- Air duct above the unit (if suction is from above): typically 100–150 mm including insulation
- Exhaust duct: another 100–200 mm for side routing
- Installation space for the installer during mounting: ideally min. 200 mm "overhead"
Realistically, therefore, plan for a minimum free ceiling space of 550–700 mm for medium-sized SLI units. This requirement is very critical in low ceilings (e.g., in older administrative buildings with a height of 2.6 m) and must be addressed with the builder before starting the cladding.
IVAR.SLS – floor and parapet fan coil: dimensions and construction requirements
Floor-mounted fan coils IVAR.SLS are a preferred choice for many designers during renovations of apartments, penthouses, reception areas, and spaces with panoramic glazing. The reason is simple: you don't manage the ceiling, you don't solve the ceiling space, and the unit is accessible for service at any time.
Typical dimensions of IVAR.SLS units:
| SLS Model | Width (mm) | Depth (mm) | Height (mm) | Air outlet |
|---|---|---|---|---|
| SLS 200 | 600 | 220 | 580 | front/top |
| SLS 400 | 800 | 220 | 580 | front/top |
| SLS 600 | 1000 | 240 | 600 | front/top |
| SLS 800 | 1200 | 240 | 600 | front/top |
The depth of the SLS unit is 220–240 mm. If the unit is installed in front of a window as a parapet unit, this depth must be considered in the interior design project. Most architects model the parapet with a depth of 250 mm, which is exactly enough – but you must ensure that the media connections (flexible hoses DN 15, condensate drain DN 16–20) can also fit behind the unit.
Floor installation of SLS – connections and sealing
Water connections for the SLS unit come from the bottom or the side (depending on the model and configuration). For floor installation, this is advantageous – the connections can go through the floor to the manifold. However, you must ensure:
- A cutout in the floor or floor profile of at least 80 × 80 mm for the passage of a pair of pipes + electrical cable
- Sealing of the cutout to prevent air ingress from the technical floor (condensation)
- Condensate drain led under the floor with a slope of 1–2% to a trap or siphon with a water seal
- Access to the front panel of the unit – at least 600 mm of free space in front of the unit for filter replacement
Media connections – general rules for SL, SLI and SLS
Regardless of which fan coil range you install, some common rules apply for connecting water and electricity.
Water connections
IVAR fan coils are supplied standard with connections G 3/4" or G 1/2" (depending on the model size). The following must always be installed on the connections:
- Ball valve on the supply and return (for the possibility of disassembly without draining the entire system)
- Drain valve or air vent screw (the fan coil must be ventable)
- Control valve (two-way or three-way) for power control – typically 230 V or 24 V drive according to the selected control
- Flexible hose (min. 300 mm long) as a vibration compensator between the fixed piping and the unit
The distance of water connections from the wall or ceiling must be at least 150 mm, so that the valves can be physically operated by hand. This is a detail that is easily overlooked during design and causes incredible frustration during service.
Condensate drainage
Condensate is formed on the evaporator in cooling mode. Each fan coil has a condensate tray with an outlet of diameter 16–20 mm (depending on the model). The drainage must be led with a minimum slope of 1 cm per meter of length, without any upward sags. The condensate hose must be thermally insulated wherever it passes through a warm environment (ceiling, wall behind the façade), otherwise additional condensation forms on it.
A siphon with a water seal of at least 50 mm height must be installed at the end of the condensate line. Without a siphon, air is sucked back into the tray, causing a characteristic "gurgling" sound and sometimes flooding of the tray.
Electrical connection
IVAR SL, SLI and SLS fan coils require a supply of 230 V / 50 Hz, single-phase. The power consumption depends on the model and fan speed – it ranges from about 40 W (small SLS 200 at 1st speed) to 250 W (SL 1200 at 3rd speed). A separate electrical circuit with a maximum fuse of 10 A and a 30 mA residual current device must be provided for each unit.
Various types of control devices are used for regulation. For simple installations, a 4-speed control 230 V for IVAR.SL and SLS is sufficient – it is an integrated control module that allows manually setting the fan speed in 4 steps (0-1-2-3) and controlling the valve. More about types of controls can be found in the article Control of fan coils – from a simple switch to smooth DC INVERTER control.
Installation box and hidden installations
For applications where the fan coil (or associated air conditioning unit) is installed in a wall or recess, special accessories are available – installation box for air conditioners and fan coils. This is a steel box that is embedded in the wall and the fan coil is inserted into it – the result is a clean, recessed appearance without a visible device.
The installation box must be installed before the final plastering, so coordination with the construction is essential. The box has a precisely defined external dimension into which it is embedded, and an internal dimension that fits a specific fan coil unit. Never insert a fan coil into a purchased box without first checking the dimensional compatibility – tolerances are typically ±5 mm.
Hygienic accessories – UVC lamps
With increasing demands on air quality, disinfecting UVC lamps in fan coils are becoming standard. For IVAR.SL and SLI 400, the UVC lamp with a length of 475 mm is available. This lamp is mounted directly into the fan coil cabinet, behind the filter, facing the evaporator.
From an installation point of view, it is important that the lamp physically fits into the internal space of a specific model – the length of 475 mm is designed for SL/SLI 400, other models may have different dimensions. Never install a UVC lamp longer than the internal width of the fan coil. The electrical connection of the lamp (typically 230 V, 18–36 W) should be handled via a switch integrated into the unit's control system, so that the lamp only lights when the fan is running – and never when the unit's panel is open (risk of eye damage).
Common installation errors – examples from practice
Over the years of work in the field of heating and cooling technology, I have repeatedly seen the same mistakes. Here is a brief overview of the most expensive ones:
- Insufficient ceiling height: The customer chose SLI 400, but the ceiling space had only 280 mm of free space. The unit itself is 195 mm in height, but with brackets and piping, it did not fit. Solution? Redo the entire ceiling in the hallway – plus three weeks of delay.
- Missing service opening: Fancoil SL 600 embedded in the ceiling without any service opening. After a year, the filter medium clogged, the fan motor overheated, and the entire cassette had to be replaced. Access to it took half a day of breaking down the drywall.
- Condensate without a trap: A classic mistake. A missing trap caused reverse air suction, the sink overflowed, and water dripped onto the ceiling one floor below. The water damaged the plaster for €800.
- Connections too close to the wall: Water valves installed 4 cm from the wall – there was no space to turn the key. During the first service, the plumber had to disassemble the entire cassette to reach them.
- Neglecting insulation of the condensate pipe: A pipe running through a warm ceiling without insulation – water condensed from the warm ceiling air and dripped onto the drywall. It looked like a leak from the fan coil, but the cause was just the neglect of insulating 3 meters of pipe.
- Incorrect hanging height of SL: The unit was hung too low – the louvers were visible from the floor throughout the entire profile, aesthetically inappropriate. The recommended height of the bottom edge of the cassette from the floor is 2.4–2.7 m.
More about the procedures to avoid these mistakes can be found in the article Installation of a fan coil – procedure, connection and commissioning and in Common fan coil faults and how to eliminate them.
Requirements for ceiling load-bearing capacity and suspension points
The weight of SL and SLI fancoils ranges from 11 kg (SL 200) to 25 kg (SL 1200). In addition, the weight of water in the evaporator (0.5–1.5 liters), the weight of accessories (control valve, valves), the weight of flexible hoses, and the weight of piping in the case of SLI must be added. The total suspended weight can easily exceed 35–40 kg in the case of large models.
Suspension points must be anchored into the load-bearing structure—not into drywall or aerated concrete blocks. The following are typically used:
- Chemical anchor M8 or M10 in concrete—minimum load capacity 1.5 kN per anchor, with four anchors you have more than a 600 % safety margin
- Threaded rods M8 with nut and washer—minimum length according to the thickness of the ceiling slab + depth of the drop ceiling
- Adjustable consoles (L or U-shaped) made of galvanized steel
Do you have a question about this topic?
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