“Idle reduction is a cost saving strategy and a driver comfort issue.”
A large U.S. fleet
Fuel-operated or diesel-fired heaters allow fleet owners to provide heat to truck cabs. They are inexpensive to purchase and maintain and some models eliminate engine cold start. However, they have limited functionality and don’t address cooling or AC power requirements.
Fuel-operated or diesel-fired heaters use diesel fuel to blow heated air (or circulate heated coolant) into the cabin (or engine) to improve the environment during cold weather conditions.
There are two kinds of fuel-operated heaters:
- 1. Also know as bunk heaters, fuel-operated air heaters act like small furnaces with a heating element and blower providing cab heat via direct ducting or via the truck’s factory-installed HVAC ducting. Heating capacities range from 6,800 to 13,600 Btu/hour. The units draw 0.7 to 11.2 amps of battery power when in use.
- 2. Fuel-operated coolant heaters provide engine pre-heat, and act like hot water furnaces. They use the truck’s supply of diesel fuel to produce the needed heat. Heat output ranges from 17,100 to 45,000 Btu/hour. Electrical consumption ranges from 1.9 to 7.5 amps.
- Inexpensive to purchase and maintain
- Burn as little as 0.02 to 0.13 gallons of fuel per hour
- Available as factory-installed options
- Integrate with other idle-reduction technologies
- Are inexpensive to purchase and maintain
- Eliminate engine cold start
- Offer higher heating capacity than engine block heaters without AC power connection
- Are available as factory-installed option
- Can be programmed for remote start
- Preheat cab and defrost windows without need for engine warm-up
- Limited functionality
- Do not meet idling needs of air conditioning or AC power
- Use engine batteries for their power so they can drain batteries
- Do not cool cab
- Do not provide bunk heat
- Do not provide AC power for hotel loads
- Consume fuel
Best Practices Study
As part of a CK Commercial Vehicle Research project, a small sample of directors and vice presidents of maintenance at heavy-duty fleets were asked about their idling practices. These fleets indicated they had best results with fuel-operated heaters and extra cab/sleeper insulation.
Executives from 11 for-hire truckload carriers were personally interviewed to find out about their idle-reduction practices. No single technology was used by all 11 of the fleets, but 10 are installing fuel-operated air heaters. The fuel-operated heater was found to be the single most beneficial option for idle-reduction.
Internet Fleet Survey
In conjunction with Michelin, the study team surveyed 200+ members of Michelin’s Fleet Forum. When asked what idle-reduction technology they would purchase 52.9% said fuel-operated air heaters. Survey respondents said diesel APUs and fuel-operated air heaters were the most beneficial idle-reduction technology. Here are comments from some of the survey respondents:
- The heaters are light, inexpensive to operate and install, and they are reliable.
- They eliminate the need for drivers to idle their trucks to stay warm.
Internet Owner-Operator Survey
In conjunction with Kevin Rutherford’s “Let’s Talk” truckers’ satellite radio forum, the study team surveyed owner-operators and small fleets. Extra cab insulation, diesel APUs and fuel-operated air heaters are the most common idle-reduction technologies that would be used by this group if they were to buy new trucks. When asked why they chose fuel-fired cab heaters for idle reduction, here is what some of them said:
- I did not want another engine to service
- Not much extra weight and it is simple to maintain
- It allows comfortable operation between +25C to -20C with minimal fuel cost, lower initial cost and low maintenance costs
- I start the heater and go to sleep; no fuss, no muss
There are already a wide variety of payback calculators for any given type of idle-reduction system. In an effort to meet the industry’s need for more information, we have also developed a high-level payback equation to aid fleets in choosing the right combination of technologies.
Every truck manufacturer offers optional fuel-operated heaters. Here is a breakdown of who offers what:
Fuel-operated heaters are relatively inexpensive both to purchase and maintain. They are offered as factory-installed options and integrate with other idle-reduction technologies.
Coolant heaters are often required in trucks operating in colder climates and are sold in conjunction with other idle-reduction technologies.