Ducts that are in a ceiling tend to be a little more effective in distributing cooled air throughout a room.
Forced air ductwork routed in attic.
In warm climates it is common practice to run heating and air conditioning ducting through attic spaces simply because it is easy to do.
Throw duct leakage into the mix and the problems are even worse.
Turbine vents usually depressurize the attic sufficiently to pull conditioned air up through the air leaky ceiling into the attic which increases the cooling energy use.
With hundreds of square feet of ductwork surface area in the attic and a δt of 75 f the air coming out of the vents in your home will be significantly higher than 55 f.
Heat pumps and ducts are part of it too.
Always stagger take off ducts by 12 to maintain pressure.
Forced air systems are usually the cheapest ones to install in homes today and a furnace qualifies as this type of system.
The first and possibly most important thing is to make a commitment to yourself to change your hvac filters regularly.
When you put the ducts in an unconditioned attic and have the minimum insulation allowed you want to move the air at a higher velocity pushing it up near the maximum recommended by acca manual d 900 feet per minute fpm for supply ducts and 700 fpm for return ducts.
This article describes heating and air conditioning ducts that have been placed in or beneath concrete floor slabs.
Use insulated duct or duct board in unheated spaces.
Hvac air ducts located inside concrete slab floors invite a surprisingly broad range of building problems that fall into two broad categories.
Hvac ductwork in floor slabs.
Flexible duct work must be stretched tightly for maximum air flow.
Having your hvac system in your attic isn t dire though you ll need to do some work to keep your air conditioner or furnace system running as efficiently as possible.
Functional troubles such as lack of air flow or collapsed ductwork and environmental problems such as.
Since most homes have their hvac system serve multiple functions at once it can be cheaper to install the unit in the attic because the roof access can make inspections maintenance and repairs at lot easier.
The passive vents probably reduced that negative effect by allowing more air to flow from the the outdoors but it s still almost always better from an energy use point of view to not use turbine vents or powered attic vents of any significant size.
Keep as much of the ductwork span as possible inside the conditioned envelope of the home.
Verify that ducts outside the conditioned zone are properly sealed.
Never locate ducts at the end of the trunk line run.
Unfortunately this practice is all too common in our northern cold climate putting air conditioning ducts in the hottest possible place in the house during the summer and putting heating ductwork through the coldest possible part of the house in the winter.
