Hvac Ducts In Attic
Looking at the cooling side only the additional load would be.
Hvac ducts in attic. If you ve studied heat transfer at all you may recall that the rate at which heat moves from a warmer to a cooler body depends on the temperature difference which we abbreviate as δt. When hvac ducts are installed in a vented attic in any climate encapsulate the ducts in closed cell spray polyurethane foam ccspf to protect them from temperature extremes in the unconditioned attic space. All the ducts are in the attic. Make sure your condensate drain pan under your air conditioning unit is not collecting sitting water.
Ductwork running along an open ceiling in the basement of a one story home is also more affordable to replace. Your hvac system will require shorter ducts. Use metal flex or fiber board ducts that are insulated to code. Why installing ductwork in the attic above an in law suite is necessary ductwork is necessary for an in law suite because without it there s no way for the air that s warmed or cooled by your furnace or air conditioner to reach that space.
Sometimes the hvac system winds up in the attic because it s the last thing on the home designer s list. Leaks and overflows on a given floor will seep through the floors to affect everything below it including your hvac system. This flat pan catches the water underneath. An attic can get up to about 130 f in the summer and the conditioned air entering the ducts is about 55 f or so.
Keep your hvac air filter clean. Having it installed in the attic ensures that it is 100 percent protected from flooding caused by plumbing leaks and overflows. The costliest are sheet metal ducts running in enclosed walls and ceilings. Mold in air ducts.
But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t. The duct insulation should include a vapor barrier cover. After all most new homes have r 49 insulation on the attic floor holladay continues. According to rightsuite the software we use the supply ducts have about 560 square feet of surface area and the return ducts 101 square feet.
So logically the ducts deserve more not less insulation. Attic hvac systems also require shorter ducts. Where possible install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Type of ductwork system the least expensive duct system is a radial system of flexible ducts in an attic running to ceiling grates.
When your air filter is clogged with dust and dirt it can quickly migrate to the condensate. Attic hvac units are potentially inefficient. When hvac ducts are installed in a vented attic in a dry climate bury the ducts in attic insulation to protect them from temperature extremes in the unconditioned attic space. When the attic is 20 f that insulation is addressing a delta t of 50 f.
R 8 duct insulation 5 227 btu hour.