Condensating Ducts, and Humid House

Originally Posted By: Perry Savas
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I recently had my old HVAC system replaced. My Sub told me to keep the same tonage system (5 Ton). My old Air Handler was from 1989, and my condenser from 1996. I live in Daytona Beach, FL and right on the beach therefore most things don’t survive salt to well. That being said, I have a multitude of new problems that I never had while running my ol system.


1st Problem - My new Variable Speed Air Handler is creating exsessive condensation in my ductwork and on the unity itself. The interior of my ducts are filled with water and ruining drywall, insulation, etc....what can be the problem ???

2nd Problem - The previous homeowner put a 400 sqft addition onto the house. They took a 14" supply right off the main trunk into this room with no return. That's about 2 Tons of Air. It worked fine before but now the trouble begins. If I leave the 14"supply open my AC runs for 6 or more hours straight. If I close the supply My AC Runs great but creates tons of moisture, I'm thinking due to the excessive tonage it's creating, and I cannot find a happy medium, but i never had this problem while the old system was installed and my AC guys are stumped. Now If I add A return in this room of adequate size could this resolve the problem.

Also, I have a new second/separate unit. My AC guys want to put a return for the new unit in a room that is cooled by the old (main) unit. Does that sound right ?

Any Help would be greatly appreciated because i am totally dumbfunded of how this new system can create sooooo many more problems and destroy my house !!

Thanks


Originally Posted By: bkelly2
This post was automatically imported from our archived forum.



Get a second HVAC contractor to check out your system.



“I used to be disgusted, Now I try to Be amused”-Elvis Costello

Originally Posted By: bking
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Make sure the condensate line is producing water. If you have one of the systems that suck air from the condensate line and no P-trap or a dry p-trap, it will blow water all over the coil and put it back into the house.



www.BAKingHomeInspections.com

Originally Posted By: dandersen
This post was automatically imported from our archived forum.



Quote:
1st Problem - My new Variable Speed Air Handler is creating exsessive condensation in my ductwork and on the unity itself. The interior of my ducts are filled with water and ruining drywall, insulation, etc....what can be the problem ???

Low airflow generally causes moisture problems on the duct system. Seeing as it is a variable speed air handler, something is not set right.

Quote:
2nd Problem - The previous homeowner put a 400 sqft addition onto the house. They took a 14" supply right off the main trunk into this room with no return. That's about 2 Tons of Air. It worked fine before but now the trouble begins. If I leave the 14"supply open my AC runs for 6 or more hours straight. If I close the supply My AC Runs great but creates tons of moisture, I'm thinking due to the excessive tonage it's creating, and I cannot find a happy medium, but i never had this problem while the old system was installed and my AC guys are stumped. Now If I add A return in this room of adequate size could this resolve the problem.

Not likely. It will improve comfort levels in that room though. And it will load up the air conditioner to capacity.

With this takeoff closed, it is possible that your air conditioner is too large. This will produce colder than normal temperatures in the duct system (producing excessive condensation), causing the unit to shut down prematurely which will not remove moisture from the house adequately.

Quote:
Also, I have a new second/separate unit. My AC guys want to put a return for the new unit in a room that is cooled by the old (main) unit. Does that sound right ?

No.
Absolutely not.

HVAC system design and balancing is a totally different business than system installation or repair.
It sounds like you need a new HVAC installer.
There are so many possibilities, it is impossible to tell from here which direction you should go. However you have excessive moisture in the house which means the unit is likely too large. It does not run long enough to remove the moisture within the house. It produces air duct temperatures too cold which ends up below the dew point temperature causing condensation to form everywhere. The air-conditioning system works on two types of heat, latent and sensible. When the unit is too large, it works mostly on the sensible heat removal. If the unit is too small, it works primarily on the latent (or moisture) heat. Air supply and delivery must be properly balanced both supply and return. Improperly sized ducts causes excessive or reduced air flow depending on design. As stated, low airflow results in high moisture condensation. If you have too many registers for the system, the airflow will drop. That 14 inch takeoff may be causing this to occur.


Originally Posted By: Perry Savas
This post was automatically imported from our archived forum.



I would liketo thank all of you for your amazing help. I called my A/C contractors and told them the information you have provided me and it seems like something is really wrong because they have hung up on me numerous times and won’t even come back out to the job. GEEESEE… So now I’m stuck with a new system that’s not up and running yet and an old system that is destroying itself.


Now I'm waiting for another company to look at the screw up
Any further Info on this subject would be a great help


Originally Posted By: gbell
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This link will allow you to file a complaint with the DBPR.


Select Contractor Licensing Board.

https://www.myfloridalicense.com/entercomplaint.asp?SID=


--
Greg Bell
Bell Inspection Service