Lev door
 | This article relies largely or entirely on a single source. (May 2024) |
Lev door is a floor-to-ceiling (full height), usually internal door, split into two parts: the lower part a standard height door leaf, the upper part typically a smaller leaf of matching design (often standard door leaf cut in half).
In cold climate, Lev doors enable effective convection of warm air through buildings from central heat sources, such as fireplaces or air conditioning units, without the need for ducting. In warm climate, the doors enable free passage of cooling cross-breezes when the main door leaf is shut. Privacy and air circulation may be controlled independently using this design.[1]
The design and function is similar to transom doors, however Lev doors are significantly more economical to construct due to their simplicity, while also allowing greater passage of air through their larger unobstructed opening.
The configuration of Lev door is similar to Dutch door, however they differ in size, configuration and purpose: The former is used internally for improved energy efficiency in sustainable architecture, the latter is used externally for ventilation and exclusion of livestock.
Advantages
- Effective convection of warm air through buildings
- Free passage of cooling cross-breezes
- Independent control of privacy and air circulation in buildings
- Simplicity and very low construction costs, about equal to standard door and wall above
- More seamless, open-plan like connection between rooms
Disadvantages
- Poor acoustic privacy with upper leaf open
- Not suitable for bathrooms, kitchens due to transfer of odours
- Operation of the upper panel by people of shorter reach requires additional hardware
History
Doors with vertically divided leaf have been in use for centuries, such as Dutch and Irish doors, transom doors and floor-to-ceiling doors (single panel), however those were typically external doors and served a different purpose.
Lev door first appeared as unique sustainability feature in buildings by Australian architect Jiri Lev.[1][2]
How Lev doors work
In buildings warmed air rises and progressively spreads from the heat source across the ceiling. As it reaches walls and cools down, it begins to descend and return to the heat source, to fill space created there by more heated air risen. Typical door openings do not reach above 0.5 to 1m below ceilings, thus allowing only limited amount of warm air to pass through into other rooms. Lev doors, like other floor-to-ceiling doors, span the full height of the room, enabling warm air to freely continue through.
Measurements indicate temperatures in secondary rooms with typical doors approximately 2 °C below those in primary rooms (rooms where heat source is located). Temperatures in secondary rooms with Lev doors are typically equal to those in primary rooms.
Where the lower panel of the door is often kept in the closed position, the full performance of the door can be maintained by a gap or screened opening in the panel close to the floor.
See also
- Dutch doors
- Transom
- Other types of doors