Water vapor is produced during the combustion of natural gas. When flue gases cool down enough, water vapor begins to condense.
What is the dew point?
It is the temperature below which water vapor in the flue gas begins to condense.
Condensing boilers
They are designed to utilize this condensation and recover additional heat.
Non-condensing systems
In these systems, unwanted condensation can cause corrosion in the boiler or the flue pipe.
Relationship with efficiency
Low return temperatures in a condensing boiler help increase the rate of condensation and overall efficiency.
