Conditioned Attic Vs Vented

The thermal boundary can be at the ceiling plane leaving the attic space above uninsulated and vented or the thermal boundary can be located at the roof line creating a sealed insulated conditioned or semi conditioned attic space.

Conditioned attic vs vented.

In colder climates the main purpose of a vented roof is to keep the roof cold and reduce the formation of ice dams. Furthermore leaky ducts can lose as much as 20 of conditioned air flow to the attic bsc 2009. The loss of energy efficiency means some designers choose to move the ductwork into the conditioned areas of the home and leave the attics unvented. Vented attic it is exposed to extremes of hot and cold.

A secondary goal is to vent moisture that infiltrates the attic from the conditioned home. Oversized heating and cooling units are often installed to. The energy needed for air conditioning and heating typically goes up 10 when ducts are in the attic ueno 2003. Choosing a conditioned attic vs unconditioned attic space comes down to what you want to do with the area and what works best with the design of your home.

Energy codes building scientists and lots of bad experiences are collectively pushing us all towards sealed aka conditioned and unvented attics. In warmer climates unvented attics can prevent the condensation that occurs on ductwork in some vented attic spaces. Which is best for your home. Vented roofs serve a number of different purposes and their roles vary from climate to climate.

This means bringing the attic into the house more like a very short second floor so it is kept warm and therefore dry and therefore clean. If you want the extra storage and don t want to take the risk of moisture buildup the unvented system is the best fit for your home. If you convert your vented unconditioned attic to an unvented conditioned attic by installing open cell spray foam on the underside of your roof sheathing you may be surprised to discover that your attic is now the most humid room in your house. Unvented attics are also said to perform better in areas where high wind events.

Although building scientists haven t achieved a consensus on the answer we. Furnaces ducts and air conditioning ac equipment run throughout the attic spaces on all levels except the dormers and the space over the outside deck.