Accurate measurements are essential when selecting and installing grilles and louvres to ensure optimal performance. Understanding the various dimensions and types of these components facilitates proper fitting and functionality.
Types of Grilles & Louvres
Weather Louvres
Installed on external walls, these louvres often include built-in insect meshes to prevent pest entry. Often made from Aluminium, though can be customised to be any RAL colour.
Egg Crate Grilles
Commonly used internally within ceilings for air extraction, featuring a grid-like design.
Double Deflection Grilles
Equipped with adjustable blades to control airflow direction, with both front and back blades adjustable.
Pressed Steel Grilles
Made from sheet steel that has been pressed or stamped into shape. These grilles are designed to protect openings in walls, floors, or ceilings while allowing air to flow through.
Understanding Grille Sizes
Grille sizes can be perplexing, as the labeled size may not correspond directly to external dimensions. Key measurements include:
Neck Size
The internal area where the grille fits into a duct or opening. For example, a grille labeled as 350 mm may have a neck size around 335 mm to fit over ductwork edges.External Dimensions
The total size of the grille’s front face and outer edges, which may differ from the labeled size.Measuring for fitting
The Opening Size
Measure the actual opening (hole) where the grille or louvre will be installed.
Flanges
Flanges (Frame) are often added around the grille to cover the opening. For instance, a 500 mm x 500 mm opening may require a louvre with overall dimensions of 545 mm x 545 mm, considering a 28.5 mm flange on all sides.
Clearance
Grilles are typically made slightly smaller than the opening (e.g 12 mm less) to allow for easy fitting without friction.
Indoor or Outdoor Applications
Suitable For Indoors
Egg Crate Grilles, Deflection Grilles and Pressed Steel Grilles are suitable for indoor air input and extraction.
Suitable For Outdoors
Weather Louvres are designed for external use, providing protection against environmental elements.
Connecting To Ductwork
Grille Boxes
Grille Boxes are often used to connect grilles to ducting, available with top or side spigots based on space constraints.
Flexible Ducting
Attach flexible ducting to the grille box’s spigot, ensuring sufficient space for bends and adjustments.
Frequently Asked Questions
1. How do I measure the neck size for a grille?
Measure the internal dimensions of the duct or opening where the grille will fit. The neck size should match these dimensions to ensure a proper fit.
2. Why doesn’t the labeled size match the grille’s external dimensions?
The labeled size often refers to the nominal or neck size, not accounting for flanges or external borders, which add to the overall dimensions.
3. Can I use indoor grilles for outdoor applications?
Indoor grilles, such as Egg Create Grilles are not designed to withstand external environmental factors. It’s advisable to use weather-rated louvres for outdoor installations.
4. How much clearance should I allow when installing a grille?
Grilles are typically manufactured slightly smaller than the opening, usually by about 12 mm, to facilitate easy installation without friction.
5. What is the purpose of adjustable blades in double deflection grilles?
Adjustable blades allow for precise control of airflow direction, enhancing the efficiency of the ventilation system.
Proper measurement and selection of grilles and louvres are vital for the efficiency and longevity of ventilation systems. By understanding these components’ dimensions and applications, you can ensure a seamless installation and optimal performance.
