Does Return Duct Need To Be Insulated

Cool air passing through warm areas in your home can cause condensation in the ductwork.

Does return duct need to be insulated.

Have to get the air back to the furnace. Typically in residential basement applications they are not insulated. Then close off that supply and insulate the ducts. Exhaust air ducts normally do not need insulation.

Un insulated cold air ducts very often have surface temperatures below the local dew point. Most technicians are skeptical about these numbers especially on the return air side of the system. Department of energy codes ashrae 90 1 2007 and 2010 indicates that returns should in fact be insulated though not usually with the same insulation thickness as the supply. As you consider adding insulation first be sure the duct system is delivering proper airflow.

Supply air ducts may be left un insulated if they run exposed through the space being conditioned. Answered october 21 2019. If its not sealed. In turn the moisture can lead to all sorts of problems such as mold and mildew growth.

Hvac ductwork sizing is critical for proper heating and cooling in every room. The most applicable repair for duct temperature loss is adding insulation. The school of thought used to be that return ducts only need to be insulated if they pass through an area where the ambient temperature will negatively affect the temperature of the returned air. Return air ducting is necessary in almost every room.

Return air ducts only need to be insulated if they pass through environments that adversely affect the return air temperature. If the return duct is subjected to unconditioned air condensation may form and it will need to be insulated. However in recent years u s. Insulation prevents condensation and dripping from ducts.

For instance a 2 5 ton system approximately 400 cfm per ton would require 2 14 flexible return ducts or 1 very short flexible 18 duct to move the 1000 cfm required by the 2 5 ton system. If the basement crawlspace is sealed add a return. Ductwork insulation prevents condensation. Be careful as you choose from the various insulation options.

This condensation leads to moisture buildup inside the enclosed space of the duct system. This arrangement also reduces system first cost.