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7. Evaluating the impact cab heaters have on reducing overall fuel use and emissions

Evaluating the impact cab heaters have on reducing overall fuel use and emissions

Project Objective: Assess the effectiveness of heavy duty class 8 truck cab heaters to reduce fuel consumption and greenhouse gas (GHG) emissions.

Organization: Siemens Transportation Group Inc. (Siemens)

Project Timeline: June 1, 2009, to October 31, 2010

Project Results: On a per unit annual average, the use of cab heaters reduced fuel consumption by 4,331L and GHG emissions by 11,650kg.

 Performance Results (per unit)

Heat Source	Fuel consumption rate	Fuel consumed (based on 1235 hours of operation1)	GHG Emissions
Main Engine Idling	3.8 L/h	4,694 L	12,627 kg
Cab Heater	0.3 L/h	363 L	977 kg
Savings	3.5L/h	4,331 L	11,650 kg

1 Hours of operation obtained from monitoring period and prorated to an annual average.

 

       Financial Results

Annual Fuel Cost Savings per Truck1	Investment per unit	Payback
$ 4,001	$ 1,500	4.5 months

1 at a fuel price of $0.9239/L

Project Description

With financial assistance from Transport Canada’s Freight Technology Demonstration Fund, Siemens purchased and installed 150 Espar D2 Air Tronic cab heaters to their trucks to provide in-cab heat during the colder winter months. Drivers were instructed to use the heaters instead of idling the main engine while in the sleeper berth, during pick-up and deliveries, while waiting for dispatch, when taking breaks or when waiting at switch points.

Methodology

Siemens collected engine data for 56 of the 150 trucks equipped with a cab heater during a 17 month monitoring period via an on-board ECM while cab heater data had to be downloaded manually. Siemens calculated the variance between existing data in pre-installation fuel consumption and the new data collected. It was assumed that the cab heater and main engine would not be running simultaneously.

The price of fuel at the time of the project and the most recent Environment Canada conversion factors at the time of this writing were used to calculate monetary savings and emissions reduction.

Detailed Project Results

A) Performance Results

Installation of in-cab heaters allowed Siemens’ drivers to turn off engines during driver rest periods in cold weather. The use of cab heaters reduced main engine idling from 27% of total truck operation time to 17%, this represents the elimination of 1,235 hours of idling annually per truck. This decreased idling time saved considerable amounts of fuel and significantly reduced GHG emissions as demonstrated in Table 1. The total project impact (for the 150 units) can be found in Table 2.

       Table 1 – Annual Performance (per unit)

Efficiency Gain1	Main Engine Idling Time Avoided 2	Fuel Consumption Reduction	GHG Emissions Reduction3
3.5L/h	1,235 hours	4,331 L	11,650 kg

1 Efficiency gain represents the difference in fuel consumption of the main engine versus that of the cab heater, established at 3.8L/h and 0.3L/h respectively.
2 Obtained from Siemens as part of the data collected during the monitoring period.
3 The Environment Canada factor of 2.69 kg/L was used.

       Table 2 – Total Annual Project Impact

Description	Total Idle Time	Total Fuel Consumption	Total GHG Emissions
Main Engine Idle at 3.8L/h	185,288 hours	704,096L	1,894 tonnes
Cab Heater at 0.3L/h	185,288 hours	54,475L	147 tonnes
Savings	n/a	649,621L	1,747 tonnes

B) Financial Results

With an annual fuel saving of 4,331L per unit, Siemens stands to save $ 4,001 per year for each cab heater deployed in its fleet. With a cost of $1,500 per unit (purchased and installed) the payback for the cab heaters is 4.5 months. Therefore, 150 units yield an additional $388,080 in net savings in the first year and an additional $600,150 for every year after that in which the cab heaters are operating.

Conclusion

Siemens demonstrated the effectiveness of cab heaters in conjunction with driver education. Per vehicle fuel savings and GHG emission reductions were, on average, 4,331 L and 11,650 kg per year respectively. For the 150 units, the annual results total 649,650L of fuel saved or $600,150 and 1,747 tonnes of GHG emissions avoided.

With a payback of 4.5 months, Siemens sees this as a cost-effective way of reducing idle-time, fuel costs and harmful emissions. In addition to economic and environmental benefits, Siemens has found that the cab heater is also a good safety feature in the event of a main engine breakdown or failure in cold weather, providing heat to the driver. Also a cab heater increases the comfort level in the sleeper berth by controlling temperature more adequately.

Siemens has learned that in severe weather conditions, drivers should not shut down the main engine to avoid potential restart issues and as such a cab heater is more effective when temperatures are above -15°C.

They noted specific challenges including resistance to installation in drivers’ living quarters as well as the man power and time required in order to manually retrieve data from the cab heater units.

Siemens recommended that a company looking to implement this technology install a simple hour meter to the unit to report hours of operation should they wish to monitor use as well as coordinate the installation with trucking operations so as to not impact the company’s ability to provide service to customers.

Date modified:

2012-02-16

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