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.
Attic return air duct.
The remaining 2 tons of capacity is at least 1 5x oversized for the actual 1 load.
If the supply ducts are high or in the ceiling then the return air ducts or grills should be low on a wall.
When return air ducts are lying on the attic floor after confirming that they re efficient and tight we simply bury them beneath a cozy layer of applegate bora spray cellulose insulation as we upgrade the attic insulation.
In the summer the return duct removes warm air from inside and transports it to the outside to be conditioned.
Return air openings for heating ventilation and air conditioning systems shall comply with all of the following.
If the supply ducts are in the floor then the return air should be located up high.
Remember the lower i can keep the return air temperature the potentially lower we get the supply air temperature.
Openings shall not be located less than 10 feet 3048 mm measured in any direction from an open combustion chamber or draft hood of another appliance located in the same room or space.
Can accept any size collar up to 18 in.
My next my project is to deal with the return ducts in my attic.
Used as a central return vent box filter grill not included.
Air handler platforms used as return air plenums can draw air from vented attics and crawlspaces through other connected framing cavities.
Without the return duct the air in the home would not be able to properly circulate.
A return duct is the part of the system that carries the air back to the furnace or air handler where it will then be circulated back out through the supply vents.
After reading bsc s article duct dynasty bsi 074 covering the ducts with closed cell spray foam seems to be the second best method next to relocating them in the conditioned space which i don t have the time or money for.
Can be easily cut to size.
While none of these spaces makes an acceptable air pathway on its own some building cavities such as floor joists can make acceptable duct chases to contain an insulated air sealed metal or flex supply or return duct.
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.
The duct board return air box is an r6 the duct board return air box is an r6 insulated box that installs traditionally in a ceiling.
The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room.
The ducts through which the air travels are part of a sealed system that usually is located in the attic for structures with slabs or under the floors on structures that are raised off the ground.
This pulls the air across your body.
So i was looking for a cheaper alternative.
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.
A 600 board foot kit of closed cell spray foam is about 600 at the distributor here but that is also out of my budget.
