Hi all

We finally moved in to the house we have been sprucing up for the last month. Last couple of days have been really hot and humid. I kept hearing an occassional 'drip' sound in the dining room. My wife and I tracked the sound to the duct in the basement.

I'll try to get a picture tonight. Basically the drip is in the main supply duct, right where the main supply has its first offshoot to the dining room supply vent. The main duct then turns 90 degrees to head to the other side of the house

Previously, I noticed the dining room supply was really pushing air, and the second floor (its a split level home) was 5-10 degrees warmer than the first floor dining room/lr/kitchen. So, I did close the damper about halfway on this supply--could that be causing this? No idea if the problem was there before I changed the damper...

None of the ducts are insulated in the basement. I didnt see condensation on the outside, FWIW. These are also, per the HVAC guy who moved two registers for me, 'really old school but well made' ducts. Thick metal (aluminum?) and screwed together.

First home with forced hot air / central air--not sure where to start on this drip thing. I am guessing its a bad thing that could lead to mold/mildew?

Thanks in advance for any and all tips and help!
K

 

Is the basement air conditioned? Are the room duct openings in the floors? Is the furnace and a/c blower in the basement?

 

Blower and furnace are in the basement. I had HVAC guys move three vents prior to move in: two went from low on the wall to the floor, but not the one I mentioned in my original post

Basement has no registers, but it mights cold when the AC runs. Not finished, either.

 

While this may or may not help with your current problem, if the basement isn't being used as living space (I get the impression it isn't), you should consider insulating the ductwork. In the winter when you're heating the house, the basement will be very cold. If the duct work is uninsulated, you'll lose heat to the basement that otherwise would have gone into the living space.

 

If it's water dripping there's probably condensation happening....could be humid room air mixing with cold dry a/c air. Did you try reopening the damper to see what happens? If you cut down the flow it is possible that the dry a/c isn't pushing the room air out. The duct work is probably galvanized metal. Are all joints in the duct runs sealed....any air leaks?

 

thanks for the replies! Sorry-- was unpacking last couple of days (a challenge with young kids!)

I opened the damper all the way. I'll see if that makes a difference.

I am planning on putting mastic on the the joints and insulating (bubble wrap) the ducts--just a whole lotta fish to fry before I get to that item on the punch list (did I mention its a fixer-upper? )

I was concerned about insulating the ducts before resolving this drip--though its sounding like insulating might BE the fix...

 

The joints are not sealed. I did pick up mastic at the HVAC supply place my HVAC guy recommended. On my 'to-do' list...

I dont feel any air leaks, but I havent tried any 'scientific' tests...

 

Is the duct where the leak is pitched?

 

hi!

I posted this pic:


I was crouching on the floor, so the perspective looks a little odd...
Blue arrows indicate airflow. The little blue one on the left shows the first offshoot that I had partially closed the damper to force more cool air elsewhere in the house. The other blue arrow to the right of that shows the cold air flow to the rest of the house.

For this segment, its all flat.

the red arrow shows where 'drip' sound manifests...

 

Drip sound could be echoing. Can any of the ductwork be separated to look inside? What happened when you resumed full air flow? Did you say you hear it with the a/c running?

 

not sure I can separate. Screwed from top as well as sides/bottoms...

I'm no expert on these, but it really sounded like it was dripping right there (to the point I tried feeling the duct there to see if I could feel something hit the bottom of the duct.

Seems to be primarily while AC is running

 

When does the drip stop? Are there any register vents nearby? Where's the closet register?
What is that circle on the bottom of the big trunk at the bend?

 

drip stops couple minutes after ac shuts off

circle is a rubber plug for accessing a 1-2" hole that i am told is for duct cleaning

closet register? sorry-- whats a closet register? new to this

 

For $60 - $70 you can buy an inspection camera at Harbor Freight. With it you can go in through the cleanout hole and take a look around. There may be less expensive devices but they attach to a computer. The HF camera has its own display.
May seem like a lot of $ for what may be a 1 time use....that was my initial feeling but it has come in handy on several occasions.
If you aren't familiar with HF, they sell really inexpensive tools, etc. A lot is not worth having but some of their stuff works well.....not made for the long haul but not bad. Somebody put out a list of things not to buy at HF....#1 - Parachute, #2 - SCUBA equipment.

 

lol!

I recently bought a heat gun from HF. This camera sounds worth the money...

 

You're aware of HF discount coupons in magazines and newspapers....usually for 20% off ? I just received one via email from HF for 25% off. It's valid until 7/24. If you would like it send me your email via PM and I will forward the email to you and you can print it.

 

Email has a coupon for the camera.....sale price $59.99.

 

wow! I saw the 25% off--didnt notice the camera. I have that email. Thanks!

 

Scroll down the email...the camera coupon should be there. I just received another email from HF with the same 25% discount and camera coupon. You probably received the same one.....if you didn't let me know and I will forward it to you.

 

Naw dont spend you money on that crap LOL spend your dollars on a bucket of IronGrip 601 duct joint sealer and a couple of chip brushes. You may NOT be able to feel the air leak but it is there, those S and Drive duct joints are NOT airtight. Use the DUCT BUTTER and you will be good to go. If you are worried about looks just use some painters tape to get a crisp clean line.

 

thanks for the tip!

Thats the medium term plan. I actually started a thread on this earlier today. I just wasnt sure if I had to deal with this 'leak' before sealing/insulating