AVS Forum banner
1 - 5 of 5 Posts

·
Registered
Joined
·
77 Posts
Discussion Starter · #1 ·
Hello,

I've been searching but couldn't find anything. As the tiltle says, can I use the semi-rigid dryer duct for my AC supply (for the theater in the basement)?


What are the good and bad in doing so?

If not what would you suggest instead?

The run is short (less than 8 feet). The flexible duct hvac specific sold at Lowes is 8' (which is too long).

I'm on a budget.


I don't have much knowledge in Hvac. So forgive me if I'm asking.

Thanks very much.
 

·
Registered
Joined
·
77 Posts
Discussion Starter · #3 ·

Quote:
Originally Posted by bobdoggy /forum/post/20815622


You can cut the flex HVAC duct to what ever length you need.

Thanks. I thought about it. Does that flex has to be enclosed in something or can it stay in the open. I would have about 2 feet in the ceiling and about 3-4 feet hanging outside of the room to the main system.


Another question: is it okay to put insulation in the joist where the AC metal/aluminum ducts are?
 

·
Registered
Joined
·
17,939 Posts

Quote:
Originally Posted by seigneur_rayden /forum/post/20813567


Hello,

I've been searching but couldn't find anything. As the tiltle says, can I use the semi-rigid dryer duct for my AC supply (for the theater in the basement)?


What are the good and bad in doing so?

If not what would you suggest instead?

The run is short (less than 8 feet). The flexible duct hvac specific sold at Lowes is 8' (which is too long).

I'm on a budget.


I don't have much knowledge in Hvac. So forgive me if I'm asking.

Thanks very much.

These are really questions for an HVAC expert .. you might want to post on one of the HVAC forums .. the diameter of the duct, the size of the system you are running it off of, the other ducts in the same line .. etc .. all will play a part in what is required .. even local codes ..
 

·
Registered
Joined
·
5 Posts
Using galvanized metal will allow the air to flow smoother (smooth interior surface) allowing more air to get to your room, but you can compensate for this by getting a larger diameter flexible duct, or using 2 (3?) flexible ducts.


I assume you are extending an already existing metal duct. You should calculate the square footage of the existing duct and try to represent that with the extension... at less than 8 feet in length there shouldn't be that much loss in air flow due to the roughness of the interior surface, so I'd say you'll be okay. Just try to pull it taut to minimize the ridges on the interior. Be sure to secure it at both ends with mechanical fasteners and seal with duct tape.


Also, since hot air rises you should have a way to let hot air leave the room (either naturally or with a fan), making it easier to cool. For instance, if you try to pump cool air into a room that is sealed (door/windows closed), eventually no air will be able to enter the room no matter how large the duct is. By 'making a hole' near the top of the room, the cool air will basically fall to the floor and fill the room up naturally pushing the hot air out.


good luck.

Quote:
Another question: is it okay to put insulation in the joist where the AC metal/aluminum ducts are?

if you live in a humid area there might be a chance of condensation around the metal which might put moisture in the batt insulation making it useless as insulation, but there are other types of insulation you could use near the ducts... but basically you'll be okay to use what ever type you'd like. You might google to see if there are duct insulations sized to work with what you have. They tend to be about 1/2" with a reflective cover/tabs w/ sticky for easy installation.


Condensation is best addressed on the cold water pipes in your house... insulate those before you enclose them behind walls.
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top