Construction of a decentralized ventilation system
Ventilation principle for decentralized ventilation units
By definition, a ventilation system is a technical system that supplies fresh air to rooms or buildings. Controlled ventilation systems can be broadly divided into centralized and decentralized systems. The key difference between the two lies in their function: Decentralized ventilation systems for industrial and residential spaces are designed so that the ventilation units are distributed in pairs across different locations within one or more rooms. Centralized ventilation systems, on the other hand, are typically installed in a central location for large residential units.
Guide topics:
- How does a decentralized ventilation system with heat recovery work?
- Structure of a decentralized ventilation unit
- How a decentralized residential ventilation system with heat recovery works
- Accessories and controllers for ventilation systems with heat recovery
- Function of pure extract air devices for ventilation
This is how decentralized ventilation systems are installed.
The first step in installing a decentralized ventilation system is planning and calculating the required air volumes. This calculation determines the number and positioning of the fans. The fans are then installed in the exterior walls according to the proposed placement. In new construction, bricks are omitted, and installation aids such as prefabricated wall-mounting blocks with integrated slopes reduce installation time and prevent typical installation errors. During renovations, a core drill is used to create an opening in an existing wall. The wall-mounting sleeve is then foamed into the resulting opening, the heat exchanger with fan is inserted, and finally, the system is covered on the inside and outside with a weatherproof hood or interior cover, and a controller is connected.ner Wetterschutzhaube bzw. Innenblende abgedeckt und ein Regler angeschlossen.
Structure of a decentralized ventilation unit
A fan as part of a decentralized residential ventilation system with heat recovery basically consists of the following components: inner cover, reversible fan, ceramic heat exchanger, wall mounting sleeve, and weather protection hood. There are also ventilation units in which air exchange takes place via a cross-flow heat exchanger. The structure and function of the ventilation system can be found in the following overview:
Inner cover
Function
- Lockable inner cover for the ventilation system
- Easy to use
- Standard with integrated dust filter
Advantages with inVENTer
- The Flair interior panel can be tilted in all directions to direct airflow, e.g., upwards or downwards. Operation in soundproof position is possible.
- Quick-release fastener via simple push-button operation.
Interior panel also available with SDE sound-absorbing insert. - The G3 or G4 dust filter can be replaced with special filters: G2 pollen filter (allergenic particles), F5 fine filter (fine deposits), or AKF activated carbon filter (deposits, odors, and pollutants).
- Easy filter replacement thanks to the easily accessible components. Completed in just a few steps.
- The IB Connect wireless interior panel is equipped with sensitive sensors and communicates wirelessly with the controller – eliminating the need for cabling to the controller.
Reversible fan (fan)
Function
- The fan, responsible for both fresh air supply and exhaust,
- in reverse mode (heat recovery), changes its direction of rotation (exhaust air vs. supply air) every 70 seconds. In heat recovery mode: Supply air and exhaust air modes alternate continuously.
Advantages with inVENTer
- The heart of the iV ventilation system
- Low power consumption (1–3 W)
- Quiet, durable fan suitable for continuous operation. inVENTer is the only manufacturer to offer a 5-year manufacturer’s warranty on the reversible fan.
- Special electronics were developed specifically for reversible operation in decentralized ventilation units.
- High performance: e.g., the iV-Office reversible fan achieves up to 90 m³/h in exhaust mode.
Ceramic core
Function
- Innovative ceramic heat storage unit including insulation for thermal insulation
- Heat recovery works according to the regenerator principle: the ceramic is alternately charged and discharged by the room heat, which can then be recovered.
Advantage of inVENTer
- High-performance industrial ceramic with high heat capacity
- Up to 93% of the room heat is recovered through the reversal of the airflow direction; on average, heat recovery rates are approximately 80–84%
- The design results in a large surface area for heat exchange thanks to the innovative honeycomb structure
- Ceramic is hygienically safe; the continuous reversing operation prevents organic contamination in the systems
- The cleaning process is simple and straightforward. The ceramic unit can be quickly removed and cleaned by the user under running water. Professional cleaning is not required.inVENTer guarantees the longevity of the ceramic storage tank with a 30-year manufacturer’s warranty.
Wall installation sleeve
Function
- Round wall penetration that is inserted directly into the exterior wall
- serves to integrate the heat storage unit and fan, as well as any other accessories.
Vorteil bei inVENTer
- Stable material that can be cut to the desired length depending on the wall thickness.
- The built-in slope allows for easy drainage of condensate.
- Thanks to the prefabricated wall mounting blocks or the unique “Simplex” wall mounting system, the wall mounting sleeve can be quickly and easily integrated into new buildings without core drilling.
Weather protection hood
Function
- External cover of the ventilation system on the facade
- Protection of the system from the elements
Advantages with inVENTer
- High-quality materials: Stainless steel, coated in white, gray, and Nord. A wide variety of other RAL colors can be ordered to match the facade.
- The specially developed design effectively directs airflow away from the facade.
- Drip edge for any condensation that may occur.
- The Flex weather protection hood includes a protective grille as standard to keep out animals. It protects against the elements and is resistant to driving rain.
How does a decentralized ventilation system with heat recovery work?
A decentralized residential ventilation system with heat recovery works as follows: In decentralized ventilation systems for living spaces, the ventilation units are always used in pairs. However, it is not always necessary to place two fans in a single room. They can “communicate” with each other through airflow openings, such as a small door gap. This principle is called cross-ventilation—it ensures that fresh air effectively circulates through the living space.
Decentralized residential ventilation is achieved through ventilation units that operate in reverse: The reversing fan of one unit rotates in one direction for 70 seconds, expelling stale air. During this time, the ceramic heat exchanger stores the heat from the exhaust air. The direction of rotation of the fans in both units then reverses, drawing fresh air into the living space. The ceramic exchanger releases the stored heat back into the incoming fresh air – a process known as heat recovery. This method can retain up to 94 percent of the heat. Due to the different fan directions, this function of decentralized residential ventilation with heat recovery is also referred to as the push/pull principle.
Zubehör und Steuerungen für Lüftungsanlagen für Wohnräume mit Wärmerückgewinnung
Accessories for decentralized ventilation systems
A wide range of accessories is available for decentralized ventilation systems. For example, inVENTer ventilation systems offer additional filter systems as well as soundproofing and wind protection accessories. For allergy sufferers or special conditions (e.g., high levels of fine dust), both pollen and fine dust filters can be retrofitted. The activated carbon filter keeps unpleasant odors at bay. Sound insulation is often a key requirement—with inVENTer ventilation systems, you can further improve this with a sound insulation insert, a soundproofing insert, and a sound protector. Wind protection is particularly important in coastal areas—we recommend installing the wind protection insert into the wall mounting sleeve.
Controllers for decentralized ventilation units
Controllers are connected to the individual ventilation units in a decentralized system. These controllers ensure that the fans are linked together and operate in pairs in opposite directions. The controllers offer a variety of functions. Simple control via a touch-sensitive interface is just as possible as ventilation control via individual ventilation zones, where a weekly timer is used to pre-program the ventilation precisely to the residents’ needs. The current state-of-the-art in the decentralized ventilation market is wireless control. Here, the fans communicate via a interference-free wireless connection—eliminating the need for cabling to the control unit. Via a Bluetooth connection from the central controller, the ventilation can also be easily and conveniently controlled via an app on a smartphone or tablet.
Function of pure extract air devices for ventilation
Exhaust ventilation units remove stale air from living spaces to the outside; they operate in one direction only and do not recover heat. Exhaust ventilation systems are frequently used in bathrooms, storage rooms, or rarely used rooms. However, it is also possible to equip entire residential units with exhaust ventilation systems.
When used in bathrooms, the units run only intermittently. The exhaust air units are equipped with humidity sensors, light sensors, or delayed-start switches and operate as needed, e.g., after showering or when humidity rises for other reasons.
In storage rooms or rarely used rooms, the units are designed for continuous operation. In addition to the exhaust units, which typically vent air to the outside 24 hours a day, air inlets are installed in the exterior walls of the living unit to allow fresh air to flow in. This effectively prevents mold and moisture. It should be noted, however, that no heat recovery takes place.