Ducted Heating And Cooling

Air ducts and return plenums are notorious for air leakage. A significant reason is that the pressurised air will find any holes, tears in the duct or gaps in the seals where ducts are connected to each other. This causes dramatic variations in air quality, airflow, temperature and humidity. To compensate, your system has to work harder to maintain the temperature set on the thermostat. Increases in your power bill may give you an indication that something is affecting the performance of the ducts.

Other indicators that the system is leaking include temperature imbalances in different parts of the home. This is especially evident in multi-story dwellings where extreme variations can occur because of air escaping and not reaching its destination.

When the air finds its way out of the ducts into the internal cavities of the home, the hot air will rise, creating a higher pressure that forces its way through any gap it can find. The low pressure at the bottom of the home then draws in cold unfiltered air from outside

Air conditioning technicians often try to rectify the situation through the use of excessively high fan speeds. This not only consumes more energy to power the fan but also amplifies the effect of the leaking air barrier.