Which louvre is right
for my project?
Enter the airflow you need and the pressure drop you can allow. This checks every Pantheon louvre and tells you which one suits, and how big the opening has to be.
Tell it what the space needs.
Estimates only. Contact Invicta for an accurate calculation and the correct louvre for your job.
Sized per opening, at ρ 1.2 kg/m³. The square panel is a way of picturing the size, not a recommendation: any opening at or above the face area will do the job, whatever its proportions. Preliminary sizing only, confirm project figures with Invicta.
Want to build the system in 3D and generate a spec pack? Open the configurator.
The maths behind the numbers.
A lower pressure limit or a lower free open area both push the panel larger. Free open area and K factor per profile are the same figures used by the configurator. Preliminary sizing at standard air density; for tender or compliance, contact Invicta for project-specific data.
The questions we get asked.
What pressure drop should I allow across a louvre?
It depends what the louvre is serving. Intake and discharge louvres on mechanical plant are commonly sized to somewhere between 15 and 40 Pa, because whatever the louvre takes has to be found by the fan. Set the limit your mechanical design can carry and the calculator will tell you how much face area that buys you.
Why does a bigger free open area need a smaller louvre?
Because free open area is the proportion of the face air can actually pass through. A louvre at 77% moves the same air through a smaller opening than one at 66%, and it does it at a lower velocity, which means less pressure drop. Zeus Hydra-Shield is the exception that proves it: it keeps Zeus's free area, and the perforated shield shows up as pressure drop instead. Free open area is the single biggest driver of how much louvre a job takes.
Which profile needs the smallest opening?
Whichever combines the highest free open area with the lowest K factor, which is why the calculator ranks them rather than asking you to pick. Zeus Hydra-Shield will always size largest, because the perforated shield that earns it Class A rain defence carries about four times the pressure drop of Zeus at the same velocity. That is the trade being made, not a fault.
Can I use these sizes for a mechanical submission?
Treat them as preliminary sizing. The free open area and K factors are our own figures, but a submission should be confirmed against project-specific data, especially where the louvre is behind a bend, a bank of plant or an acoustic element. Send us the opening schedule and we will size it with you.
Does the panel have to be square?
No. The square panel is only a way of showing the size in a form you can picture. What matters is the face area: any opening with at least that area will move the air, whatever its proportions. Very wide or very tall openings may need intermediate mullions, which we will pick up on the shop drawings.