Noncondensing

Noncondensing refers to heating equipment, particularly boilers, that do not condense water vapor in the exhaust gas to recover latent heat. In these systems, combustion heat is transferred to the heating medium, and the exhaust is vented at a higher temperature since no condensation heat is captured. Condensation does not occur within the heat exchanger.

Efficiency and terminology are commonly described using AFUE, the annual fuel utilization efficiency. Because latent heat is not recovered, noncondensing boilers generally have lower energy efficiency than condensing models. In many markets, typical AFUE values for noncondensing boilers are in the mid-70s to mid-80s percent range, while modern condensing boilers commonly exceed 90 percent.

Advantages of noncondensing boilers include lower upfront cost, simpler components, and compatibility with older venting systems. Disadvantages include higher operating costs over the life of the unit, greater heat loss through the chimney, and greater potential for not meeting contemporary energy codes or incentives that favor high-efficiency equipment.

Noncondensing boilers remain common in older buildings, retrofit scenarios, or regions where cost considerations outweigh efficiency gains. In new construction or upgrading programs, many codes encourage or require condensing equipment or other high-efficiency solutions.

In broader usage, noncondensing can describe processes or devices in which condensation of vapor does not occur, but in technical and everyday energy contexts it is most closely associated with boilers and heating systems. See also condensing boiler, AFUE, and energy efficiency standards.