Having a good ventilation system in a building is crucial to providing a comfortable, safe environment and ensuring odours are removed effectively. The ventilation system should go unnoticed, therefore it is important to select the correct components for the system design and requirements.

Ducting Design

Rigid ducting should be used as far as practicable, with flexible ducting reserved for final connections and alignment. In such cases, it is crucial that the flexible duct is pulled taut, with no kinks and minimal bends which lead to poor efficiency and air flow.

Spiral ducts are often used for their self-sealing attributes; leading to fewer leaks and consequential improved performance and efficiency. The internal pressure is even throughout the duct, ensuring an even and efficient air flow.

Such ducting is common in applications requiring low noise. The reduced reverberation when compared with a standard rectangular duct, results in a lower noise level, while the smooth internal surface also results in less turbulence-induced noise.

Spiral ducts offer an economical solution, are easy to maintain and take up minimal space.

Fan Options

Selecting an inline mixed flow fan can lead to up to 2.5 times the pressure supplied by a standard axial fan. The air flow produced is significantly more powerful and the fans are noticeably more compact, making them more suitable for applications with limited installation space.

The fans are simple to connect and can be mounted horizontally or vertically, adding to their versatility. They are also often constructed modularly, making maintenance simple with minimal disruption.

In addition to these benefits, the inline mixed flow ventilation supply fan is a quiet piece of equipment, which is essential in many applications such as offices and shops. Noise from a ventilation installation may also be mitigated by using an attenuator.

Grilles and Diffusers

The inlet to a ventilation system must be protected from pollutants, pests and weather. A weather louvre will normally incorporate some form of bird or rat netting and sometimes filtration to protect against particulate matter. The profile of the louvres prevents rain ingress to varying degrees.

Ventilation supply ports can take various forms

• An eggcrate grille, with a large free air flow area, is ideal in a return air stream.
• Double deflection grilles have a layer of horizontally oriented blades, followed by a layer of vertically oriented lades. They offer a quiet solution, producing a flexible air distribution with relatively low velocity.
• Ceiling diffusers are designed in a variety of sizes. They are easily cleaned, with a spring loaded, removable centre.
• Circular ceiling diffusers distribute large quantities of air but with minimal noise.

In order to easily connect a spiral duct system to the selected grille or diffuser, a plenum box is required. These are often constructed of metal, although plastic plenums are also available for aesthetic or weight saving reasons.

There are numerous variations of ventilation system components. Your supplier can assist in selecting the most appropriate components for your system design and application.