First water dripping off of your ducts and onto your insulation can cause the insulation to compress which decreases it s r value or ability to insulate.
Condensation on ac ducts in attic.
Improper or no insulation of ducts.
The primary ways to stop ducts from sweating is to raise the surface temperature of the ducts or to lower the dew point of the air surrounding the duct by some form of dehumidification.
Persistent ductwork sweating may eventually lead to water damage.
This type of insulation should be standard but since you have a condensation problem it s obvious that the contractor.
There are two main ways to solve this problem.
Over time condensation dripping from your ductwork onto attic insulation can cause it to compress which lowers its r value.
The last usual cause for condensation on a duct system is if the ducts are not properly hung or they are touching each other.
What causes condensation on ac vents.
Condensation on air ducts can be a serious problem.
Ductwork located in an attic must be hung properly so that the insulation can do its job.
Excessive condensation can also create conditions favorable to mold or mildew forming in areas surrounding the duct itself.
When ductwork is touching it forms a very cold spot where they are touching thus condensation begins.
Ducts sweat because the outside surfaces of the ducts are below the dew point of the air in their immediate surroundings.
When water condenses and drips into your attic or home it can cause a some serious secondary problems.
It can also feed mold growth and cause ceiling joists to rot and sheetrock to disintegrate leading to unhealthy air quality in your home and the need for costly structural repairs.
When the hot humid attic air contacts the cold duct or the cold duct boot the moisture in the air condenses on the cold surface just like the condensation that happens on a cold can of beer.
Whenever there is a contact between the hot humid air and cold metal surface then there will be sweating or condensation on the metal surface so it is very important to have a proper insulation for the air handler ducts in case the portion of the duct is coming in contact with the unconditioned air outside.
The condensation forms when air of a different temperature meets the grill box and duct connecting the vent to the air conditioning unit.
Keeping the temperature of the metal connected to the grill.