EN 81-20 establishes a rather wide range for the temperature of the shaft and machine room, which must be properly ventilated
VENTILATION AND AIR CONDITIONING ARE KEY
elements to ensure a safe and comfortable environment for users of lifts installed both indoors and outdoors. Let us look at some of the solutions available.
VENTILATION (SHAFT AND MACHINE ROOM)
Standard EN 81-20 assigns responsibility for the design of shaft ventilation to the building designer, while the lift in staller must provide the necessary information including heat dissipation from lift components. Although the standard has no specific requirements in this regard, it is important to ensure adequate ventilation in both the shaft and the machine room, even if the lift is stopped for an extended period of time due to a fault. EN 81-20 stipulates that the temperature of the shaft and machine room may vary be tween +5° and a maximum of +40°.
VENTILATION (CAR AND MACHINERY ROOM)
In areas with warmer climates, it is common to require ventilation systems to ensure air circulation even inside the car. Some companies install air extractors on the roofs of the structures. These can be either fixed, with a fan that rotates in response to the movement of hot or cold air, or motorised, which is more effective but requires adequate maintenance. Regarding the ventilation of electrical parts (suchas switchboards and inverters), it is important to place them in protected areas. In some cases, the machinery room is airconditioned to maintain temperatures within a well-defined range.
VENTILATION LOUVERS (SHAFT) Many shafts start
in an unheated basement, pass through heated floors and end in an unheated attic. Cold outside air can enter the crawl space through open or uninsulated basement windows and rise into the shaft. In addition, the suction generated by the movement of the car can draw warm air from the heated rooms through the lift’s imperfectly sealed doors. Finally, heated air escapes from the ventilation openings at the upper end of the shaft. In this case, it is advisable to install ventilation louvres at the upper end of the shaft. If the compartment adjoins an unheated room or the outside environment, it should also be thermally insulated. It is advisable to combine maintenance of the lift with maintenance of the air vents.
Ventilation inlets must be installed in accordance with current fire regulations.
INSULATED OR SANDWICH PANELS (CAR)
Insulated panels, also known as sandwich panels, can be used to clad the lift shaft. Sandwich panels offer numerous advantages such as light weight, resistance to water and moisture, and excellent sound insulation without compromising mechanical strength. They are durable and provide high reaction and fire resistance performance. They also provide optimal thermal insulation and reduced heat transmission. They consist of two thin, strong outer layers of cladding enclosing an insulating core, usually polyurethane or rock wool.
PLASTERBOARD FOR OUTDOOR USE (SHAFT)
Plasterboard for outdoor use has excellent thermal insulation characteristics, especially with regard to high temperatures. It is therefore particularly suitable for structures that are exposed to the sun for many hours a day, where glass, on the other hand, could encourage heat build-up. Outdoor plasterboard sheets are applied to the structure until it is completely covered. The sheet consists of a central part made of high-density, water-resistant calcium sulphate dihydratewith glass fibre and biocide additives (to prevent mould growth). The outer surface consists of a water-repellent coating made from a mixture of binders and additives, which provides excellent protection from the weather. The sheets can be manufactured using up to 84% recycled material, and at the end of their life cycle they can be 100% recycled. The lift shaft infill with exterior plasterboard can be plastered and painted with the same finish as the building, thus providing visual continuity between the building and the lift shaft.
THERMAL BREAK DOORS, GUIDES AND HEATED THRESHOLDS (CAR) In the case of external lifts in exist
ing buildings, it must be considered that common lift doors are not airtight. This problem can be solved by fitting thermal break doors. In thermal break doors, the door leaf is thermally insulated by the use of an insulating material positioned internally or thermal laminated glass with a chamber, which also contains insulating material that guarantees a lower thermal transmittance than a normal swing door. Thermal transmittance is an index measuring heat loss. The lower the thermal transmittance value, the better the door insulation. Special magnetic gaskets are attached to the contact surfaces between the jambs and the door leaf, while the baffle seal on the threshold is achieved by an automatic moving gasket that is activated when the door opens or closes. Heated thresholds and guides on the car door operator are also available on the market for particularly cold climates.
INSULATING GLAZING (CAR AND SHAFT)
Insulating glazing or double-glazing makes it possible to deal with the problem of heat transmission that occurs by conduction and radiation, maintaining the right balance between the internal and external temperatures. They are a combination of two or more panes of glass with the same or different characteristics, separated by a cavity (into which dry air or argon gas is introduced), with spacer channels in composite material to reduce thermal conductivity, all hermetically sealed with special glues.
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Source: www.anacam.it/anacam_magazine
