classification of ventilation

It is common to classify ventilation systems by functions, distribution strategies, ventilation principles - or by combinations of them all.

Classifying by Function
It is common to classify a ventilation system by function:

Ventilation - Supply and evacuating of air with the main purpose to keep the atmospheric climate according the requirements
Climate - Supply and evacuating air with main purpose to keep the temperature and the atmospheric climate according requirements
Heating or cooling - Recycling system with the main purpose to supply the building with necessary heat or cooling
Combined system - The functions above more or less combined in one system
Classifying by Distribution
A ventilation system can also be classified by distribution:

Centralized - A central plant supplies and extract air to and from the whole building
Decentralized - Each room/area of the building has it's own ventilation unit
Combined - Both centralized and decentralized systems used
Classifying by Ventilation Principle
A ventilation system can also be classified by the ventilation principle and air flow:

Displacement air flow through the room - CAV (Constant Air Volume) or VAV (Variable air volume
Mixed air flow through the room - CAV (Constant Air Volume) or VAV (Variable air volume.
Examples of Ventilation Systems Classifications
Single-Zone Constant-Volume System
Single-Zone Constant-Volume System with Reheating
Multizone System
Induction Unit System
Variable-Air-Volume System
Dual-Duct System