Supply ducts in an unconditioned attic must have insulation equal to or greater than r 6.
Return air ducts in attic.
A return air temp b outside air temp c airflow across evaporator coil d return air leaks from attic if you measure supply and return temperatures at the grille and at the air handler you can get an good idea of where your biggest losses are occurring.
Total rater measured duct leakage must be equal to or less than 8 cfm25 per 100 square feet of conditioned area.
At 21c i d guess you have a lot of leaks on the return side.
Visual inspection for prior attempts to improve return air such as holes cut into an existing return air duct or worse openings cut to admit more makeup air into the air handler from an un conditioned space such as an attic or crawl area.
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.
I have a couple questions.
Put the crimped end in first then put the other end of the duct in.
Return ducts in my attic.
I ve replaced the supply ducts and have insulated and encapsulated my crawlspace according to the best methods presented on this site.
If the supply ducts are high or in the ceiling then the return air ducts or grills should be low on a wall.
This pulls the air across your body.
This is kind of like a transfer grille except that it involves ductwork.
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.
Ted also has inherited a powered attic ventilator.
Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal.
A mismatch in return air inlet grille or duct size will reduce the system s effectiveness.
Without the return duct the air in the home would not be able to properly circulate.
All other supply ducts and all return ducts in unconditioned spaces must have insulation equal to or greater than r 6.
The 1 800 square foot brick ranch in climate zone 4 dates from the 1960s but the previous owner installed both a furnace and ductwork in the attic just four years ago.
My 1948 ranch house has supply ducts in the crawlspace return ducts in the attic.
Typically we cut into your ceiling near the door install a duct above the room run it through your attic and install the other end in the hallway near the central return.
It s called a jumper duct because it allows return air to jump from your room to the hall.
The damper control indicator will show you whether the damper is open or closed.
The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room.
If the supply ducts are in the floor then the return air should be located up high.
That s right your heating and air system is nothing more than a big circulation unit.
