What is an example of convective distribution system heat loss?

In a convective distribution system, heat loss primarily occurs through the movement of air. Duct leakage into unconditioned spaces is a prime example of this type of heat loss. When ducts that are supposed to carry warm air are compromised by leaks, the heated air can escape into areas that are not climatically controlled, such as attics, crawlspaces, or garages. This loss compromises the efficiency of the heating system and can lead to increased energy consumption as the system works harder to maintain the desired temperature.

Unlike duct leakage, the other choices involve heat loss through different mechanisms. For instance, heat escaping through walls typically involves conductive heat loss, where heat transfers through solid materials. Similarly, heat radiating from boiler pipes is an example of thermal radiation loss rather than convective. Lastly, radiation loss from windows occurs through the transfer of infrared energy, which is distinct from the convection process. Thus, duct leakage into unconditioned space specifically represents convective heat loss in the context of a distribution system.