Air Ducts In Attic

I was wondering is there any figures on the expected energy temp lose.

Air ducts in attic.

The air ducts for a central hvac systems are typically located above a home in the attic or upper crawl space or underneath a home in the space between the foundation and the floor so you don t see them unless you have cause to replace them. According to nrel researchers david roberts and jon winkler moving the ducts from a vented attic to a new location inside the conditioned space will reduce electricity used for cooling by 15 to 20 and will reduce the size of the needed air conditioning equipment by 0 5 to 1 ton. If your home does not have an hvac system and you plan to add one you will need to have new ductwork. The really bad news is that with old metal duct systems the only option is replacement of the ducts to stop the rain in the attic.

In more cases than not a 3 ton ac with the ducts in the attic has a ton or so of load that s just from the location of the ducts in the attic and the associated duct gains leakage etc. We were contacted by the owner that wanted us to clean the air ducts in a rental property as the tenants were complaining about the quality of the air. Jump ducts which do not directly deliver conditioned air from the hvac unit may be located in attics if all joints including boot to drywall are fully air sealed with mastic or foam and the jump duct is fully buried under the attic insulation. Locate the source of the thermal leaks by inspecting the ductwork while the air conditioner is running.

The remaining 2 tons of capacity is at least 1 5x oversized for the actual 1 load. What i ve observed attic temp 50c vent temp 21c attic temp 37c vent temp 18c attic temp 25c vent temp 13c not sure what the r value off flexible duct or main metal duct is. I live in montreal and had a lennox air conditioner and ducts installed in the attic. Assuming your ductwork is located in the attic refer to the steps below for a quick and easy do it yourself solution to thermal leaks.

Steps to sealing attic air ducts. Use zip ties to secure any loose ducts to the attic floor. This air leaks into your attic space and never reaches your living area which may lead to you adjusting your temperature. Over time the insulation on the exterior of old metal ducts deteriorates letting the hot air come in contact with the very cold metal and this is worst when it comes to condensation.