Fire Apparatus Exhaust Filtration Questions, Answered.

Direct-source filtration is a vehicle exhaust protection method connected directly to the vehicle exhaust train. Because it is physically part of the exhaust system, it helps address exhaust at the apparatus rather than relying only on a station-mounted system.

No. NO SMOKE 2 is installed after the vehicle’s emissions system and before the diffuser tip, so it does not interfere with the vehicle exhaust system. Ward Diesel has certified testing showing NO SMOKE 2 creates less back pressure than a 90-degree elbow.

NO SMOKE 2 is designed for 2007, 2010, and newer model engines using modern emissions systems. It features a high-performance substrate with a proprietary wash coat that helps remove gaseous matter and provide cleaner air inside the firehouse and other enclosed structures.

Ward Diesel NO SMOKE is fully automatic and does not require manual hose hook-ups in the station. Because the system is mounted on the vehicle, it can also support exhaust protection beyond the apparatus bay.

The advanced design of NO SMOKE 2 filters is intended to require no routine maintenance or cleaning.

For original NO SMOKE filters, filter-change frequency can vary based on the timer setting, engine age, sulfur content of the fuel, and number of cycles. In general, many fire departments go 2 to 3 years between filter changes.

NO SMOKE 2 systems are pass-through filters that are always on from cold start until the engine is turned off.

The original NO SMOKE system automatically activates upon startup and when the transmission is placed in reverse during re-entry to the station. This helps make system use more consistent and less dependent on manual action.

No. Ward Diesel NO SMOKE is an on-board system. It provides freedom of movement because there are no hose drops locking the vehicle into a specific bay and no hanging hoses swinging in the fire station.

NO SMOKE 2 systems are always on, so no override switch is needed because exhaust is filtered continuously while the vehicle is operating.

For older apparatus, the original NO SMOKE system can provide cleaner emissions on scene with the flip of a switch. The override feature activates the filter system when needed.

Yes. For ambulances staged near hospital doors, the system can be activated to reduce hazardous soot exposure around hospital personnel, emergency crews, patients, and visitors. This helps avoid the need to shut the vehicle off in situations where that may not be practical due to weather or operational needs.

NFPA 1500 9.1.6 states that fire departments shall prevent exposure to firefighters and contamination of living and sleeping areas by exhaust emissions.

OSHA measures permissible exposure limits over a time-weighted average 8-hour day. Common exposure concerns include carbon monoxide, sulfur dioxide, diesel particulate matter, nitrogen oxide, nitrogen dioxide, and other hazardous compounds found in exhaust.

Ward Diesel states that NO SMOKE meets and exceeds OSHA, NIOSH, and NFPA requirements for exhaust protection.

Diesel exhaust is a complex mixture of toxic compounds, including diesel particulate matter, commonly called soot. It can also include nitrogen oxides, polyaromatic hydrocarbons, sulfur dioxide, and carbon monoxide.

Some particles are visible as soot or smoke, while others are extremely small. The smallest particles are a health concern because they can penetrate deep into sensitive areas of the respiratory tract.