Due to internal or external heat sources (passengers, lights, electrical equipment, sunshine through the windows) temperature inside coaches may rise beyond 20° C even for much lower outside temperatures. In this case the coach may be cooled by outside air through an excessive operation of ventilation. This saves energy for air-conditioning.
Technology field:Optimisation of comfort functions
General information
Description
General criteria
Status of development: in use
Excessive ventilation is currently being used in some trains at German DB AG and at Swiss SBB (double-decked IC2000).
There may be some improvement potential in the control algorithms of excessive ventilation.
Motivation:
Energy saving
Benefits (other than environmental): none
(no details available)
Barriers: medium
Technological
A control algorithm for excessive ventilation is required. Ventilation equipment must allow for variable and excessive operation.
Passenger comfort
According to Swiss SBB there were initial problems with the system due to excessive air flow within the coach. This problem has been resolved in the meantime.
Success factors:
Combining this measure with other improvements of climatisation requiring an intelligent tool, e.g. a smoothened operation of coach climatisation (cf. IC 2000).
Applicability for railway segments: high
Type of traction: electric - DC, electric - AC, diesel
Type of transportation: passenger - main lines, passenger - high speed, passenger - regional lines, passenger - suburban lines
In principle, all passenger coaches may be equipped provided that technological conditions such as variable and excess operation of ventilation equipment are given.
Grade of diffusion into railway markets:
Diffusion into relevant segment of fleet: < 5%
Share of newly purchased stock: < 20%
German DB AG: Excessive ventilation is a standard in all newly purchased
passenger stock.
Swiss SBB: IC 2000.
Market potential (railways): high
Excessive ventilation is expected to become a standard in new stock in mid-term perspective.
Example:
Swiss IC 2000.
Environmental criteria
Impacts on energy efficiency:
Energy efficiency potential for single vehicle: < 2%
Energy efficiency potential throughout fleet: < 1%
Other environmental impacts: neutral
Economic criteria
Application outside railway sector (this technology is railway specific)