[Max MD]

Hi all, I am currently finishing my own basement (I am not a contractor or anything, just a DIYer). The ceiling of my basement is still exposed. I can see the metal pipes that carry air from the utility room to the first floor (See photo) . Now I need to make ductwork in my basement. My question is, can I just cut a hole in these pipes to branch an air duct into the basement? or will I have to start a whole new pipe from the furnace/AC to the basement?

If it's okay to cut the hole in the pipe and just install an air duct, what is the part name that I should buy to install this duct? saddle duct?

P.S: I checked and I know that my air compressor has sufficient capacity for my basement.

 

[supers05]

No. Not any of those pipes. There should already be some for the basement, near the windows. Adding any more will starve upstairs if air. (it's worse if you have a second floor.)

How did you check that your ac or furnace has the capacity for the basement.

Cheers!

 

[Max MD]

No. Not any of those pipes. There should already be some for the basement, near the windows. Adding any more will starve upstairs if air. (it's worse if you have a second floor.)

How did you check that your ac or furnace has the capacity for the basement

Cheers!

Thanks a lot for your answer. These metal pipes are out of the main trunk and are extended throughout the basement ceiling leading to the air registers in the first floor. There are about four different pipes, all leading to first-floor registers but nothing (around window lines) that are dedicated to the basement.

I checked the capacity of the air compressor and compared it to the square footage of the house and it was more than enough.

 

[Nealtw]

Each new run has to come from the main trunk like the ones for upstairs. And you will also will need return air to make them work.

 

[Max MD]

Each new run has to come from the main trunk like the ones for upstairs. And you will also will need return air to make them work.

Thanks a lot for your answer. This helps. What is the difficulty level of such a task? I mean is it something that people can diy?

 

[Nealtw]

Thanks a lot for your answer. This helps. What is the difficulty level of such a task? I mean is it something that people can diy?

Adding one, I might do it myself but figuring out what you need and where, I would have a pro. . The guys here might help with the design but they would need a lot of information and unit size, square footage and plans , size of trunks. Most times the new run is taken from the top of the main, making them more difficult.

Then have you considered the difficulty heating both up and down with one T stat. That does not always work well.

 

[SpentPenny]

You will not regret having is done correctly. There is a reason people spend many years learning HVAC. I too enjoy DIY and saving money, but a HVAC system that doesn't work right is a regret I can sure do without, not to mention how it might trash your resale value.

 

[supers05]

Thanks a lot for your answer. This helps. What is the difficulty level of such a task? I mean is it something that people can diy?

Where do you live. Code here requires some hvac in every occupied level. Are your absolutely sure that you have none for the basement? Even if you don't, most people close them off almost completely, as it's too cold in the summer, too hot in the winter.

Cheers!

 

[Max MD]

Where do you live. Code here requires some hvac in every occupied level. Are your absolutely sure that you have none for the basement? Even if you don't, most people close them off almost completely, as it's too cold in the summer, too hot in the winter.

Cheers!

I live in MD. You are right I saw that there is one damper right at the bottom of the main trunk (which is in the basement). so that might be it. But it is not near the windows. In all cases, I have to run three new lines (two for the living area ) and one for the bedroom.

Is there any benefits to using the Flexible Duct as opposed to the rigid metal pipes to run from the trunk to the rooms?

 

[supers05]

Is there any benefits to using the Flexible Duct as opposed to the rigid metal pipes to run from the trunk to the rooms?

No. They are worse in every way except ease of installation.

The 1 vent damper in the basement is probably all you needed. The installer got lazy and didn't run it to a window.

You are rerunning or installing new lines? Why? It's usual to need to do that on the first floor of a relatively new house. (<30 years old.)

Cheers!

 

[huesmann]

Is your basement completely unfinished?

 

[Max MD]

Is your basement completely unfinished?

yes

 

[roughneck]

I checked the capacity of the air compressor and compared it to the square footage of the house and it was more than enough.

Equipment isn’t sized via square footage. And basements have much different heat load characteristics then the main floors of the home. Meaning when your main floor needs air conditioning, the basement could need heat and a little dehumidification. But because the system is operating in air conditioning, the basement will be cold and humid.
Mini splits are best for this. As they can operate in whatever mode is needed for the basement and not be affected by other areas of the house.

 

[user_12345a]

Equipment isn’t sized via square footage. And basements have much different heat load characteristics then the main floors of the home. Meaning when your main floor needs air conditioning, the basement could need heat and a little dehumidification. But because the system is operating in air conditioning, the basement will be cold and humid.
Mini splits are best for this. As they can operate in whatever mode is needed for the basement and not be affected by other areas of the house.

Close the basement vents in summer, run a dehumidifier which also throws off some heat - problem solved.

Possibly dv gas fireplace or if electricity is very cheap, some baseboard heaters for the shoulder seasons.

Mini-split sounds like overkill.

 

[supers05]

Mini-split sounds like overkill.

Depends on the use case. For most houses, I'd agree with you though.

Cheers!