Louvre vents
Louvre vents
Aluminium ventilation louvres supplied and fitted as part of the glazing package: plant rooms, service areas, screened openings and continuous facade runs.
Scope of works
Ventilation louvres for plant, service and screened openings.
A louvre goes into an opening that has to move air: a plant room, a substation, a bin store, a riser, a car park, or a run across a facade screening something behind it. It has four jobs at once. Pass enough air to meet the mechanical schedule, resist the weather, stop people seeing in, and sit properly in the elevation.
We supply and fit the range as part of the aluminium package, so the louvre is drawn, coloured and fixed alongside the windows and doors either side of it rather than ordered separately and made to fit afterwards. Send the free area required and the opening size and we will confirm which system meets it.
Standard specification
IKL33: 34mm blades at 60 degrees.
Our standard louvre, and the one most schedules end up with. The close pitch and steep blade angle give sightproofing and weather resistance, and the 36.2mm frame suits openings that will not take a deeper system.
It trades free area for that performance and is the lowest of the four standard systems at 43.5% physical. Where a schedule needs more air through the same opening, we move up the range.
- Blade centres
- 34mm
- Blade angle
- 60°
- Frame depth
- 36.2mm
- Physical free area
- 43.5%
The system manufacturer's published specification for the IKL33, tested to EN 13030:2002.
The number that matters
Free area is quoted two ways. A schedule means one of them.
Every louvre carries both figures and they are a long way apart. Specifying against the visual figure is the most common reason a louvre arrives undersized for the plant behind it.
59%
Visual free area
The proportion of the opening you can see through. It describes appearance, not airflow, and it is always the larger of the two.
43.5%
Physical free area
The proportion air can actually pass through, with the blades and frame deducted. This is the figure a mechanical schedule refers to and the one we size from.
Both figures are the IKL33's. Send the free area required and the opening size and we will confirm which system meets it.
The range
Wider blades, more air, less screening.
That is the trade-off across the range. Wider blade centres raise free area and the view through; closer centres give sightproofing, better weather resistance and a shallower frame.
| System | Blade centres | Angle | Visual | Physical | Frame depth |
|---|---|---|---|---|---|
| IKL30-PFA50 | 30mm | 59° | 58% | 50% | 36.2mm |
| IKL33 Standard | 34mm | 60° | 59% | 43.5% | 36.2mm |
| IKL50 | 50mm | 45° | 79% | 50% | 64.2mm |
| IKL75 | 75mm | 45° | 86% | 57% | 80.8mm |
Continuous louvres
The same blades run across a whole elevation rather than sitting in separate framed panels. Reinforcement bars are pre-assembled with glazing clips and concealed once the blades are in, so the line reads unbroken.
- IKCL33 34mm blades, 43.5% physical
- IKCL50 50mm blades, 50% physical
- IKCL75 75mm blades, 57% physical
- IKCL95 95mm blades, 56% physical
Turret louvres
A roof-mounted box louvred on its sides, for intake and discharge at high level. Built from the 50mm, 75mm or 95mm blade to suit the airflow, flat topped, sloping, hipped or bespoke, and able to serve intake and discharge together using divider plates, insulated or not. Maximum free area is 57%, using the 75mm blade.
Plenum boxes
A folded and welded aluminium box behind the louvre, for connecting mechanical and electrical ventilation equipment. Spigots are usually rectangular or circular, the internal face can be insulated, and each box is fabricated to the job.
Figures are the system manufacturer's published specifications, each tested to EN 13030:2002. Which system suits an opening depends on the free area required, the depth available and the exposure, and that is settled at survey.
Specifying it
Five frame options, chosen to suit the opening.
The blade system and the frame are specified separately. Which frame you need depends on the construction the louvre goes into, and drawings rarely show it, so it is worth settling at survey.
How it meets the opening
- Flange frame
- A flange laps onto the face of the opening and covers the joint.
- Glaze-in frame
- The louvre glazes into a window or curtain walling system in place of a pane, in 24mm, 28mm or 32mm to suit the sightline.
- Rebate frame
- The frame sits into a rebate formed in the structural opening.
- Face fix frame
- Fixed to the face of the building where there is no reveal to work into.
- Structurally glazed frame
- For elevations where the louvre has to read as part of a structurally glazed line.
Worth asking for
- Drainage channel
- Takes water caught by the blades away from the opening rather than down the wall behind.
- Insect and bird mesh
- Fitted behind the blades where the opening leads somewhere that needs to stay clear of both.
- Any RAL or BS colour
- Powder coated to match the surrounding glazing or the wall behind. Anodising to special order.
Recent installations
Two more, on other sites.
Louvres normally form part of a wider glazing package. Six bespoke units went into the courtyard elevations at Heal's on Tottenham Court Road, in a golden brown against black windows.
Common settings
Openings a louvre usually closes.
Survey, access and the existing building decide the final route. These are the settings this work usually goes into.
Related commercial services
Work that usually comes with louvre vents.
Common questions
Louvre vents, asked and answered.
How is a louvre sized?
On free area, and there are two kinds of it. Visual free area is what you can see through. Physical free area is what air actually passes through, tested to EN 13030:2002, and it is the lower number and the one a mechanical schedule means. We size from the physical figure.
Which louvre do you fit most often?
The IKL33, at 34mm blade centres. It has the lowest physical free area of the four at 43.5%, against 50%, 50% and 57%, so where a schedule needs more we specify up from it.
Are louvres fitted with the rest of the glazing?
Yes. We supply and fit the range as part of the aluminium package, so the louvre is drawn, coloured and fixed alongside the windows and doors either side of it rather than ordered separately and made to fit afterwards.
Where do louvres usually go?
Plant rooms, substations, bin stores, risers and ducts, car parks, back-of-house areas and screened facade runs. Colour and frame details are coordinated with the surrounding glazing where the package allows.
What we can put on a pre-qualification questionnaire.
- Constructionline Gold Pre-qualified for public and private sector tendering.
- SSIP accredited Health and safety assessed under the Safety Schemes in Procurement umbrella.
- DBS-checked operatives For schools, care settings and any site where the check is a condition of access.
Commercial enquiry
Send us the louvre vents brief.
Drawings, a window schedule, elevations or site photographs are all useful, and none of them is required. A postcode and a description of the building is enough to get a sensible answer back.
- Phone lines are open 24/7.
- The office team picks up drawings and schedules during working hours.
- commercial@fensterglazing.com