Humid basement causing mold problems

Reply

  #41  
Old 08-01-18, 07:14 PM
Member
Thread Starter
Join Date: Dec 2006
Posts: 81
The basement has a drop ceiling in all but 1 room. I can check the area you mention for leaks, I had read that long ago. But it is very hard to get to in most areas on the inside and covered by siding on the outside.

I checked with the basement door closed and there is air blowing under it into the basement. All supplies in the basement are open. Do I need to reduce the return?
 
Sponsored Links
  #42  
Old 08-07-18, 02:05 PM
Member
Thread Starter
Join Date: Dec 2006
Posts: 81
As I continue to monitor humidity levels in the basement, they have seemed to remain near 54% which is a huge improvement. The difference seemed to be switching the fan from "On" to Auto. I thank everyone for their input especially Bud.
 
  #43  
Old 08-07-18, 02:19 PM
Member
Join Date: Oct 2008
Location: New England
Posts: 10,308
Likes Received: 11
You are welcome. We covered a lot of ground which is good as many improvements can be added to your list to be done when they are convenient. But you definitely moved in the right direction

Best
Bud
 
  #44  
Old 08-08-18, 07:22 AM
Member
Thread Starter
Join Date: Dec 2006
Posts: 81
The downside is that it is still warmer on the 2nd floor than it has been in the past. Most of the vents are closed on the 1st floor, some vents are open in the basement.

Regarding the spare bedroom on the 2nd floor.... What if I were to close that supply vent and cover the return vent in that room? Wouldn't that make it a non issue? Perhaps doing that would force more cold air into the other 2nd floor rooms.
 
  #45  
Old 08-08-18, 07:34 AM
Member
Join Date: Oct 2008
Location: New England
Posts: 10,308
Likes Received: 11
My retention is definitely poor so I may need to be reminded, but so far we have been addressing humidity and this room has a heat/cooling issue.
I did a quick scam through the thread and didn't see the attic mentioned in terms of insulation, recessed lights, or ducts. Also, does that room have a lot of windows? Fill me in.

Bud
 
  #46  
Old 08-08-18, 08:18 AM
Member
Thread Starter
Join Date: Dec 2006
Posts: 81
Yes, the main issue had been humidity in the basement. I had this spare bedroom isolated since we rarely use it. I had kept the supply vent closed and the door closed. When we were troubleshooting, you suggested I open all vents in all rooms to prevent a pressurization problem of pulling outside air into the home. So this spare bedroom has been all open for a few weeks. I was hoping that I could isolate it once again to try and divert some of the cool air going into that room into other 2nd floor rooms. If I simply close the supply vent, would the cold air return in that room suck air from the outsize some how?

We have not addressed attic insulation. It has what the builder put in. I'm sure more could be added. There are no recessed lights in our house at all. There is no ductwork in the attic. That room does have 2 fairly large windows that get morning sun, but no afternoon sun. We keep the blinds on those windows closed.
 
  #47  
Old 08-08-18, 08:56 AM
Member
Join Date: Oct 2008
Location: New England
Posts: 10,308
Likes Received: 11
So, you aren't concerned about the temp in this room but hoping to divert some of the cooling capacity to the other room. One of the reason I suggested opening up that room was to increase the total load on the ac unit. Being on the large size can result in shorter run times and less humidity removed. Closing off that room would be a small step in the wrong direction, but we really don't know the effect.

One test I did not see was to time the on and off cycles when it is hot out. Proper design will size an ac unit to run almost continuous at peak temperatures. There is actually two pieces of data with those on and off times. On time tells us how fast the ac unit can cool the house while off times tell us how fast the house is gaining heat.

No problem testing with that room isolated now that you can monitor temp and humidity to know what is changing.

One thought (out of my comfort zone) would be to check to see if your blower has a higher speed option. That might move more air to compensate for closing off that room.

Bud
 
  #48  
Old 08-09-18, 11:01 AM
Member
Thread Starter
Join Date: Dec 2006
Posts: 81
Humidity levels in the basement are staying pretty consistent around 54%. I am making some small changes and continuing monitoring.

I timed the AC run time this morning when the outside temp was 77, and it ran for 12.5 minutes.
 
  #49  
Old 08-09-18, 01:29 PM
Member
Join Date: Oct 2008
Location: New England
Posts: 10,308
Likes Received: 11
Unfortunately 77 is probably way below your high temp which is close to the design temp. I won't wish any super hot temps on you. but when mother nature sends some your way repeat the measurements. Also time the off cycle.

Did you look at your fan controls to see if it offers a low-med-high option?

Bud
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes