What is Aluminum Condensing Flue

Aluminum condensing flues are used in the manufacturing of commercial boilers and other heating equipment. They are made of aluminium and provide high efficiency and flexibility. The flue gas temperature is usually over 100 degrees Celcius for domestic boilers, and as high as 200 degrees for industrial appliances.

In a condensing boiler, the combustion products, including the flue gas, condensate water and heat, are used to raise the temperature of the heating water. This helps to improve the efficiency of gas-fired appliances. However, the high acidity of condensed flue gas can also cause damage to the fired heating surface. Hence, it is important to maintain good air and water quality in a boiler.

A flue pipe made of aluminum is made for gas boilers with flue gas temperatures up to 200 degrees Celsius. It is suitable for both positive and negative-pressure operation. The flue pipe is available in concentric or parallel configurations. The concentric ones have a diameter of 60/100mm. Single-wall flue pipes are also available.

A waste heat recovery unit can be used in a boiler to recover the heat from flue gases. A finned tube heat exchanger diverts the hot flue gas into a bottom receiver. Inside the finned tubes, water flows and cools the flue gas. A few condensers use heat exchangers while others are in direct contact with the flue gas.