Façade Based Ventilation
The F-Series e-stack ventilation units are designed for rooms which have access to the exterior and with a floor to ceiling height of at least 3.5m in part of the room. It is ideally suited to classrooms which have an external wall and where a sloping roof has been designed so that high level windows can be introduced at the rear of the classroom, thereby allowing additional natural daylight into the space. An F-Series e-stack ventilation unit is located directly under one of the high level opening windows. The F-Series controller is used to control the window (or variable control damper) above the F-Series unit as well as one other high level window.
In winter the system uses a mixing ventilation strategy. Fresh air is brought in through the window or damper immediately above the F-Series unit, where it is then mixed with hot interior air before being released into the room. Hot polluted air is exhausted from the room through the other window controlled by the F-Series controller. By using this e-stack strategy, the heat gains which arise in the room are used for heating the incoming air during the occupied time rather than a radiator which is required in conventional upflow displacement ventilation mode to preheat incoming air at low-level. The heat gains within heavily occupied spaces (e.g. school classrooms) are often sufficiently high that additional heating is not needed until the external temperature falls to somewhere in the range 5-10°C, depending on the U- value for the room.
Once the external temperature has increased such that air can be brought in at low level directly onto occupants without pre-heating, the ventilation strategy for the system changes to upflow displacement ventilation. Windows or low level vents are opened, as well as the high level windows or dampers so as to maximize air flow and to minimize build up of heat in the space.
For more information please download the F-Series PDF document in the Download box.