Glossary Overview:
This document provides a comprehensive glossary of terms and symbols related to ventilation systems, focusing on fan mechanics and performance metrics. Key terms include flow speed, impeller diameter, static and dynamic pressure, airflow volume, and various sound power levels. Units of measurement are specified for each term, such as meters per second (m/s) for flow speed and Pascals (Pa) for pressure.

Technical Specifications:
The glossary includes detailed definitions of technical terms like AC (Alternating Current), DC Motor, and IP Rating, which classifies the protection level of electrical products. It also covers building regulations and standards, such as CENELEC for electrical standardization and IEE Regulations for electrical installations.

Fan Types and Applications:
Different fan types are described, including axial and centrifugal fans, each suited for specific applications based on pressure requirements and ducting runs. The document explains the use of mixed flow fans for short duct runs and mechanical ventilation systems like MEV and MVHR.

Noise Levels and Sound Measurement:
The document discusses noise levels produced by fans, emphasizing the importance of fan selection and installation quality. Sound power levels are expressed in decibels, and the document explains the correlation between sound power and aerodynamic loss. It provides a formula for calculating total sound power and details on sound pressure levels and frequencies.

Fan Laws and Performance Calculations:
Fan performance is governed by specific laws, such as the relationship between volume flow and rotational speed, and pressure changes with impeller diameter. The document outlines calculations for absorbed power and total pressure, emphasizing the impact of density and size changes on fan performance.

Additional Information:
The glossary includes terms related to air quality and safety, such as RH (Relative Humidity), VOC (Volatile Organic Compound), and thermal overload protection. It also covers practical aspects like filter classes and the significance of UV stabilization in materials.