Heating supply
Air ducts are a very important part of the heating system of your house. They carry the air that needs to be conditioned and supplies conditioned air to the living space.
If they don’t have a very good insulation – especially the ones from unconditioned spaces- they will lose from 10% up to 30 % of energy used in heating your home.
Another effect of defectuos insulation is that the rooms connected to the problematic ducts experience „cold blow” – they have low temperatures of the heating supply.
Indoor ducts are more protected and may not require insulation. But, the advice is to offer them a protection. They can be affected by condense on the duct’s walls and you must be sure that the conditioned air will be sent at the needed temperature.
The material used for insulation is rigid fiberboard. Every climate requires a certain R-value for the project. Make an inquiry about the level that you need in the unconditioned spaces.