Does Return Duct Need To Be Insulated

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.

Does return duct need to be insulated. These ductwork tips will help balance your air conditioning and heating system. Ductwork insulation prevents condensation. 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. Hvac ductwork sizing is critical for proper heating and cooling in every room.

Most technicians are skeptical about these numbers especially on the return air side of the system. Answered october 21 2019. Insulation prevents condensation and dripping from ducts. However in recent years u s.

Exhaust air ducts normally do not need insulation. This arrangement also reduces system first cost. If the return duct is subjected to unconditioned air condensation may form and it will need to be insulated. Cool air passing through warm areas in your home can cause condensation in the ductwork.

Have to get the air back to the furnace. Un insulated cold air ducts very often have surface temperatures below the local dew point. This condensation leads to moisture buildup inside the enclosed space of the duct system. If the basement crawlspace is sealed add a return.

Then close off that supply and insulate the ducts. As you consider adding insulation first be sure the duct system is delivering proper airflow. Condensation will cause a multitude of issues that you definitely want to avoid. Return air ducting is necessary in almost every room.

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 its not sealed. In turn the moisture can lead to all sorts of problems such as mold and mildew growth. Return air ducts only need to be insulated if they pass through environments that adversely affect the return air temperature.

Typically in residential basement applications they are not insulated. Some insulation types offer high promises but fail to consistently perform in the field.