CWNSJ gas-fired indirect hot water boiler

Fuel type: natural gas
Typical application: business, hotel, hospital, office building, district heating supply etc.
Thermal efficiency: ≥92%

Non-pressurised indirect hot water heater, also known as non-pressurised hot water boiler with built-in heat exchanger. The unit itself operates at normal atmospheric pressure thanks to the built-in heat exchanger which bears the pressure of the system. The boiler is not classed as a special equipment therefore not subject to extra restrictions and can be installed anywhere. Combining the advantages of both pressurised and non-pressurised boilers, the CWNSJ is ideal for supplying heating and hot water in high-rise buildings.

The CWNSJ automatic gas-fired hot water boiler is a full wet-back reverse flame shell boiler. It is fitted with a large furnace ensuring the air within is evenly distributed. The fuel is atomised by the burner and burns in the furnace at a positive pressure. The high-temperature flue gas makes a 180-degree turn along the furnace and the returned flue gas is redistributed as a result of the entrainment effect triggered by the flame, achieving an even temperature distribution within the furnace. This effectively inhibits the formation of NOX. The returned flue gas is then pushed to the front smoke box and turns 180 degrees into the tubes releasing heat. Eventually, it enters the rear smoke box and is discharged into the atmosphere through the chimney. The CWNSJ is fitted with the latest technologies such as automatic air-fuel control, automatic water supply control, programmable start-stop and automatic operation. It also comes with automatic safety features such as water temperature control, automatic thermal cut-off and automatic high-pressure cut-off. This type of boiler is safe and highly efficient. It generates less pollution and noise. Its compact design makes it easy to install and operate.