Save energy without compromising on indoor climate
The reason for adjusting the airflow is simple. It is not necessary to supply the same air volume to rooms when they are empty as when they are crowded. With Constant Air Ventilation (CAV), the airflow is constant and often set to a higher volume to avoid low air supply when the room is filled. Of course, this means that an unnecessary amount of air is supplied when the room is completely empty. The solution to this is called demand controlled ventilation. VAV and DCV are two types of demand controlled systems that allow adjusted air flows which help to save energy.
One purpose - two different systems
VAV and DCV systems fulfill the same purpose, to adapt ventilation and air conditioning to varying levels of people and activity in the premises. In general, it is possible to achieve greater energy savings and better indoor climate with a more advanced system. However, there are of course applications where simpler systems work well. What, then, are the differences and benefits of the two options respectively?
VAV - Variable Air Volume
- Less advanced demand control where the air flow may vary over an operating time and may be adapted to e.g. temperature or air quality
- Meet the requirements for most simpler projects, such as preschools and smaller schools
- Normally implies lower investment costs compared to DCV
- Often provides good energy savings compared to CAV
DCV - Demand Controlled Ventilation
- Advanced demand management that adjusts air flows and temperature depending on the activity and occupancy of the premises e.g with different operating cases
- Greater opportunity to adapt comfort according to different customer needs
- Most often air and waterborne products may be combined for a complete indoor climate system
- A clearly contributing installation to reach high classifications in various building certification programs, for instance BREEAM, WELL and LEED
- Great opportunities to save energy as the system is highly adaptable
Advanced, not complicated
It is of great importance to keep the premises ventilated correctly for the best productivity and performance, health and well-being. However, in most types of buildings, the level of activity varies around the clock, meaning that empty rooms are far too often ventilated as if they were full.
The most advanced system to cope with varied activity and occupancy is DCV. In terms of demand controlled ventilation, advanced means a smart system that is technically well developed and that doesn’t add complexity. The smart system enable extra opportunities to maximize comfort, avoid unnecessary energy consumption and thereby minimise cost.
Three basic functions with DCV
- The air is directed to where the actual need is
- Always stepless
- Always supervised
DCV regulates based on
- Temperature - to keep the right temperature in the room
- Air quality - to ensure an optimal indoor climate for performance, health and well-being
- Humidity – to make certain the building is not exposed to mold-promoting moisture content
- Occupancy - to save energy when the room is empty
Since the ventilation is based on peoples’ presence and their needs, the system runs on "economy speed" as soon as the demands decrease in the building
→ See our solutions for demand-driven systems