Comfort Environments - Selecting Ventilation System
The cooling capacity of an air-condition system is often determinant for selecting the type and the principle, and the capacity is often limited by comfort requirements.
Maximum capacities for displacement and mixing systems in different kind of buildings are roughly indicated below.
| Type of building | Ventilation system | Ventilation principles and Cooling loads (W/m2) | |
|---|---|---|---|
| Mixing | Displacement | ||
| Offices | CAV | 0 - 20 | 10 - 30 |
| VAV | 20 - 60 | 20 - 60 | |
| Fan-coil | 40 - 70 | ||
| Cooling ceiling | 60 - 100 | 60 - 100 | |
| Hotels | CAV | 0 - 20 | 10 - 30 |
| VAV | 20 - 50 | 20 - 50 | |
| Fan-coil | 20 - 50 | ||
| Hospitals | CAV | 0 - 20 | 10 - 30 |
| VAV | 20 - 60 | 20 - 60 | |
| Cooling ceiling | 60 - 100 | 60 - 100 | |
| Public buildings | CAV | 0 - 20 | 10 - 30 |
| VAV | 20 - 60 | 20 - 60 | |
| Department stores | CAV | 0 - 20 | |
| VAV | 20 - 80 | ||
| Fan-coil | 40 - 100 | ||
The heat load in typical rooms are influenced by the use of lights, heat emission from machines like computers, the number of people and the sun radiation through windows and other building elements. The heat load is typically very dynamic and for larger building and systems some kind of computerized tools are helpful in the designing process.
Heat loads in some typical rooms are indicated below:
| Typical rooms and their heat loads | Heat Load (W/m2) |
|---|---|
| Normal offices without automatic | 0 - 30 |
| Normal offices with automatic | 30 - 50 |
| Conference rooms | 20 - 75 |
| Data rooms | > 60 |
| Guest rooms, normal standard | 0 - 25 |
| Guest rooms, high standard | 25 - 50 |
| Patients rooms | 0 - 20 |
| Treatment rooms | 20 - 60 |
| Intensive rooms | > 50 |
| Conference rooms | 20 - 75 |
| Theater, cinema | 40 - 60 |
| Restaurants | 30 - 70 |
| Class rooms | 20 - 50 |
| Food | 20 - 40 |
| Normal | 30 - 60 |
Related Topics
• Ventilation
Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more.
Related Documents
Classification of Ventilation Systems
Ventilation systems can be classified by functions, distribution strategies or by ventilation principles.
Ventilation Efficiency
The efficiency of a ventilation system may be related to temperature and/or pollution concentrations.
Ventilation Principles
Some commonly used ventilation principles - short cut, mixed air, displacement and piston principle.