Modification of target temperature in passenger coaches

evaluated

The target values for temperature and ventilation inside passenger coaches have a great influence on the energy demand for coach climatisation. In many cases these target values can be slightly modified without reducing customer satisfaction while at the same time reducing energy consumption. Often such a change in the operation of air-conditioning can even improve passenger comfort.

Technology field: Optimisation of comfort functions



General information

	Description
		The energy demand for coach climatisation is esentially determined by the target specifications for coach temperature and ventilation. In many cases these target values can be slightly modified without reducing customer satisfaction. Such minor modifications can have a substantial energy saving effect. Extensive studies were carried out in the Netherlands showing that both the temperature and the ventilation flow rate can be lowered without adversely affecting passenger comfort. There could be a particular potential for such measures in regions or times of the year with extreme climatic conditions. For example, on cold winter days most people will perceive 20 degrees as too hot and unconvenient given their clothing. The opposite is true on hot summer days.

General criteria

	Status of development: test series
		Dutch NS conducted studies on the feasibility and saving potential of modifications made on target temperature and ventilation rate. A measure to implement the findings is on the way.

	Time horizon for broad application: in < 2 years
		Following a detailed assessment of the current situation and possible areas of improvement, a modification of air-conditioning "policies" could be implemented in one year's time.

	Expected technological development: not applicable
		(no details available)

	Motivation:
		Save energy Raise passenger comfort

	Benefits (other than environmental): small
		Passenger comfort In some cases (especially for extreme climatic conditions) passengers may even find less climatisation more comfortable.

	Barriers: medium
		Customer satisfaction Decision makers may fear negative effects on passenger comfort.

	Success factors:
		Detailed studies and surveys on felt passenger comfort at different temperatures for extreme outside climatic conditions.

	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
		(no details available)

	Grade of diffusion into railway markets:
	Diffusion into relevant segment of fleet: not applicable
	Share of newly purchased stock: not applicable
		The grade of diffusion into fleet is not an applicable criterion since the described measure is not vehicle-specific, but rather a fleet-wide policy. Besides NS Reizigers nothing is known about a systematic assessment of potential for reducing target values for temperature and ventilation rate.

	Market potential (railways): not applicable
		(no details available)

	Example:
		Modification of target values at NS Reizigers Within the framework of the energy convenant at Dutch NS, studies were conducted on the feasibility and saving potential of modifications made on target temperature and ventilation rate. The criterion applied is that a minimum of 90 % of the passengers have to be satisfied with train comfort. A measure to implement the findings is on the way in NS Reizigers. It is estimated that the total energy demand of NS Reizigers could be reduced by 1-3% by the following measures: Reduce coach temp. by 3-4 K for– 10°C outside temperature by 0.5 K for 5°C outside temperature Costs are estimated to be very small.

Environmental criteria

	Impacts on energy efficiency:
	Energy efficiency potential for single vehicle: < 2%
	Energy efficiency potential throughout fleet: 1 - 2%
		NS Reizigers estimates that the total energy demand could be reduced by 1-3% by the following measures: Reduction of coach temperature by 3-4 K for -10°C outside temperature by 0.5 K for 5°C outside temperature

	Other environmental impacts: neutral
		(no details available)

Economic criteria

	Vehicle - fix costs: none
		Costs are very small.

	Vehicle - running costs: minor reduction
		(no details available)

	Infrastructure - fix costs: none
		(no details available)

	Infrastructure - running costs: unchanged
		(no details available)

	Scale effects: not applicable
		(no details available)

	Amortisation: < 1 year


Application outside railway sector (this technology is railway specific)

Overall rating

	Overall potential: very promising
	Time horizon: short-term
		A modification of target temperature in passenger coaches can in many cases lead to a win-win-situation for energy efficiency and passenger comfort. The measure can be realised without technological investment and will have considerable fleet-wide saving effects. Detailed assessment of passenger satisfaction could remove acceptance barriers in railways.

References / Links: Dongen, Fiechter 2000

Attachments:

Related projects: Modifications in temperature and ventilation control

Contact persons:

date created: 2002-10-09