DIY Home Improvement Forum banner

Splitting HVAC flex duct

16K views 16 replies 6 participants last post by  psilliman001 
#1 ·
Hello all,

I am new on this forum and need help with a HVAC issue.

I am converting my garage into a workshop and want to run AC into it. Fortunately, my home was a model home so the garage is already finished. The only thing I need to do is reconnect the duct work for that space. The duct work is still in the attic space, it's just been disconnected and tied off.

So, I need to know what components I need to split the current duct. I don't have a clue about the correct terminology, but I hope my explanation is clear enough.

Thanks for any help!

Dave
 
#4 ·
Holly crap what an install.


But to your question. You have 12" flex duct. So if you take a 2" piece of 12" single wall pipe and insert it into each end 12" and use the zip tie straps that should take care of reconnecting. Where the two end met on the pipe wrap with duct tape.
 
#5 ·
Actually I need to connect both pieces of flex into the other flex that you see attached to the wall. The two pieces of disconnected flex you see in the pics are the return and feed duct (if that's what they're called. They disconnected the return and feed lines from the unit before the house went up for sale. I suspect they had some type of T split if that's possible.

That make sense?

Reread my original post and I don't think I did a good job of explaining the situation.
 
#6 ·
Perfect sence.

However, I don't know any code that allow return air to a garage. Think about it. CO, Ordors and combustables into the house.

How many vents do you have in the garage?

What make you think the two ends just don't go together?
 
#8 ·
Your garage is 1 hour rated for fire from the rest of the house. That is why when the house was sold the runs had to be disconnected. Code states that you can have no heat runs or returns connected to the house system. Carbon monoxide problems could cause big problems. Also if a fire starts in your garage/shop you want some kind of barrier from the house.

Use a seperate system in the garage.

I'm with plumber, wow what a install. This was a modelhome??????:whistling2:
 
#9 ·
Actually, if you have garage doors large enough for a car to enter the garage. Its a code violation. To connect those ducts. Weather you use it for parking a car or not.
 
#10 ·
Take the ties off the to ends in the pic and turn on the blower fan. See if you get air blowing out one of the two. If so connect the two end.

If you have 3 vents in your garage they may be "T" or "Y" somewhere.

For get the term return you only want supply air to a garage
 
#16 ·
Dude, didn't you read what the man said about the monoxide issue and the fire break? You can't penetrate the garage wall even for supply

And I guarantee that ac won't carry the load on the garage anyway.

Builder's who use the garage for an office will close down all the dampers to divert air to garage. The garage is never calculated in the sizing of the ac.


And damn! -who did the install Stevey wonder or Ray Charles?
Around here the builders have been using all window units .
 
#11 ·
OK, thanks everyone. If it's a code violation, I'll look into something else. I did have an HVAC tech come out and quote me two options.

1. just hooking everything back up for $750
2. create a new zone for $1950

Was hoping to do option 1 myself and save a little.

I'll try what you recommend plumber and see what I get.

Thanks!
 
#14 ·
Its because a car in the garage can be left running. An fill the garage, and duct system with CO(caron monoxide), and kill the occupants that are still in the house.

A different system.

Can't have any duct communication with the system that conditions the occupied areas of the house.
 
#17 ·
garage ducts , NO NO

please pay attention to all who say no to ductwork in the garage... Perfect example is my wifes new remote starter operator was so sensitive just putting her keys in her pocket or purse would start the car & we would find it running , (outside) , but it could have been in our garage too. We had it de tuned somehow , please play safe!!!!!!!! our inspector for our new attached garage made the drywall guy come back and box in the roller shaft so the garage was gas tight as possible.. Jack:whistling2::thumbup:
 
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