With FVPpulse, LTG presents a new development that replicates the natural movement of the air and consequently helps buildings “breathe”. The FVPpulse decentralised supplied air and return air unit extends the principle of easy-to-implement, non-stationary air flow to office premises. Unlike conventional facade-mounted ventilation units, FVPpulse does without separate air ducts for outside and exhaust air: instead, it has a single fan and just one opening in the facade and uses a system of dampers to switch cyclically between the intake and outlet functions. This non-stationary ventilation results in the thorough mixing of the air in the room at low air velocities and high air volumes. Despite its slimline design, FVPpulse can supply air at a rate of up to about 240 m³/h. The FVPpulse units have fewer main components than conventional facade-mounted ventilation units. While offering the same performance, they are more compact, prevent flow short-circuits at the facade and ensure a comfortable air flow through the room.
Heat recovery unit protected against freezing
A shut-off damper, a large-format air filter and a regenerator for heat recovery purposes are mounted between the fan chamber and the facade-mounted weatherproof grille. The changeover between “breathing” in and out protects the regenerator against freezing because the return air constantly reheats the slats. The air velocity in the regenerator is low because, unlike in the case of counterflow heat exchangers, the air flow passes the entire heat exchanger cross-section in only one direction, thus making silent operation possible. The achievable heat recovery level depends on the length of the intake/outlet cycle and can exceed 90 percent.
Non-stationary indoor air flow for maximum thermal comfort
The post-treated and filtered outside air is periodically injected into and drawn out of the room. The resulting flow pattern in the room is a pulsed flow in which the supplied air penetrates deep into the frequented area. The periodic nature of the flow results in a greatly reduced air flow velocity. Only a time-lapse video of the flow characteristics can illustrate how harmonious waves of fresh air slowly spread out through the entire room. And there is another advantage: since supplied air and return air are never conveyed at the same time, it is almost impossible for a short-circuit to occur in the air flow.
Using multiple FVPpulse units lets buildings breathe
Buildings that can breathe thanks to the installation of FVPpulse units do not need any cost-intensive air ducts or central return air unit: all that is required are soundproofed overflow ports (LTG type LDO-T) to the corridor areas, for example above the doors. These apertures permit the exchange of air with the corridor area, thus reducing the CO2 concentration and ensuring the effective ventilation of the indoor zones.
When buildings breathe in this way, it is neither necessary nor desirable to synchronise the individual decentralised FVPpulse units. The differing “breathing” in and out cycles of the individual units promote a cyclical air exchange in the combined building areas and prevent unwanted local pressure increases in the building.
The unique mode of operation of these units makes it easy to implement innovative ventilation concepts:
- If demand-controlled ventilation is required, then the intake function can, for example, be activated by means of a CO2 sensor that detects the quality of the ambient air. As a result, ventilation is performed and energy consumed only when people are actually present.
- In the case of night-time ventilation in the summer, the units on one side of the facade are used as supplied air units and those on the opposite facade as return air units. The resultant tangential ventilation is then performed without active heat recovery and uses the cool outside air to cool the building with the windows closed.
- Hybrid ventilation is another unique function: On hot summer days, the alternating breathing function can be deactivated and the return air can escape through the facade with the window ajar. Since only supplied air is now conveyed when the alternating “breathing” function has been deactivated, the cooling capacity of the units is now doubled. What makes this so special: The supplied air volume is doubled while the acoustics remain the same.