Fully premixed low nitrogen condensing boiler refers to a boiler using fully premixed combustion technology. Fully premixed combustion refers to a combustion mode in which natural gas is fully mixed with air according to a certain proportion before combustion and air is no longer needed to be supplied during combustion.
The difference between ordinary gas-fired boiler and fully premixed low-nitrogen condensing boiler lies in whether air and natural gas are mixed before or after entering the burner.
A condensing boiler can condense the water vapour in the flue gases and withstand the corrosive and acidic qualities of the flue gas condensate. Although most boilers can condense the flue gasses, only boilers that have heat exchangers constructed from materials able to withstand the corrosion should be used in condensing application. Condensing boilers with primary and secondary heat exchanger do not work well as they are not able to fully condense and defeat the purpose of using a condensing boiler. Also, boilers with this arrangement are prone to condensation in the primary heat exchanger at lower firing rate which can cause damage to the heat exchanger.
The condensing boiler burns carbon-based fuel with oxygen in order to produce steam and carbon dioxide. The gases that escape this process (through a chimney) as exhaust are called flue gases. The major advantage is that they offer up to a 90% improvement in terms of efficiency when compared to standard gas boilers. Overall, condensing boilers are considered much more efficient in contrast to non-condensing gas boilers, a major consideration for any business running on a budget.
