Learn About Idling Reduction Technologies (IRTs) for Trucks and School Buses

On this page:

Benefits and methods for reducing idling
Behavioral strategies for reducing idling
Idling Reduction Technologies (IRTs)
Types of SmartWay verified IRTs for trucks

Benefits and Methods for Reducing Idling

Driver comfort is essential to the job of long-haul trucking, and sometimes truck drivers must run their engines to stay warm or cool in their trucks while resting.
But long-duration idling is also costly to the driver, to the fleet owner, and to the environment.

Each year, long-duration truck idling results in the following estimated or approximated figures:

1 billion gallons of fuel consumption
11 million tons of carbon dioxide (CO₂)
180,000 tons of nitrogen oxides (NO_x)
5,000 tons of particulate matter (PM)

Benefits from reducing long-duration idling include:

Decreasing fuel costs,
Decreasing engine maintenance costs;
Extending engine life;
Improving operator well-being by decreasing noise levels; and
Decreasing emissions that are harmful to the environment.

There are two ways of reducing idling:

Behavioral strategies; and
Idling Reduction Technologies, which are assessed and verified by EPA.

Behavioral Strategies for Reducing Idling

Both driver training and financial incentives are effective strategies to reduce idling.

Driver/Operator Training: Educating drivers and operators about the impacts and adverse effects of long-duration idling can help change their behavior.
Financial Incentives: Fleet owners can offer financial incentives to drivers to reduce idling. Many large trucking companies already offer these incentives and have reported success in reducing idling times below national averages.

Idling Reduction Technologies (IRTs)

In extreme weather conditions, truck drivers must idle, but there are IRT devices that allow operators to shut down the main propulsion engine by using a device.

IRT devices allow engine operators to reduce long-duration idling of the main propulsion engine by using an alternative technology.

An IRT device generally has the following three main characteristics:

Is installed on a vehicle (e.g., bus, truck, locomotive, automobile, marine vessel, equipment, etc.) or at a location;
Reduces unnecessary main engine idling of the vehicle or equipment; and/or
Provides services (e.g., heat, air conditioning, and/or electricity) to the vehicle or equipment that would otherwise require the operation of the main drive engine while the vehicle or equipment is temporarily parked or remains stationary.

Types of SmartWay Verified IRTs for Trucks and School buses

There are five types of verified IRTs that EPA has found to reduce emissions on long-haul, Class 8 trucks when compared to the truck’s baseline emissions.

1. Auxiliary Power Units and Generator Sets (APU/GS)

An APU/GS device contains an EPA emission-certified engine (certified under 40 CFR Part 89). APU/GS devices supply cooling, heating, and electrical power.

2. Fuel Operated Heaters (FOH) aka Direct Fired Heaters (DFH)

FOHs are small, lightweight heaters that burn fuel from the main engine fuel supply or a separate fuel reserve. They provide heat only and can be used in conjunction with cooling systems depending upon the cab comfort needs. FOHs provide similar benefits for school buses.

3. Battery Air Conditioning Systems (BAC) (Battery operated heating and/or cooling system)

A BAC system uses batteries to power an independent electric cooling system. Typically, these systems integrate a FOH to supply heating.

4. Thermal Storage Systems (TSS)

A TSS collects heat energy as a truck is driven, and uses it to provide air conditioning.

5. Electrified Parking Spaces (EPS) / Truck Stop Electrification (TSE)

Electrification refers to a technology that uses electricity-powered components to provide the operator with climate control and auxiliary power without having to idle the main engine. This can be on-board equipment (e.g., power inverters, plugs), off-board equipment (e.g., electrified parking spaces or systems that directly provide heating, cooling or other needs), or a combination of the two.

An EPS system (also known as Truck Stop Electrification) operates independently of the truck’s engine and allows the truck engine to be turned off as the EPS system supplies heating, cooling, and electrical power.

The EPS system provides off-board electrical power to operate the following:

Independent heating, cooling, and electrical power system;
Truck-integrated heating and cooling system; and/or
Plug-in refrigeration system that would otherwise be powered by an engine.