Air Conditioning - Not enough return???
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jsh1975
07-10-08, 08:31 PM
I upgraded from a 3ton to 3.5ton unit. What are some signs I do not have enough returns in the house?
Codyy
07-10-08, 10:18 PM
Is the cooling even in your house? Any noises from ductwork?
jsh1975
07-11-08, 05:06 AM
Upstairs stays a about 10-15 degrees warmer.
ecman51`
07-11-08, 07:20 AM
How does the air blow out of registers up there, compared with downstairs ones. If noticeably less force -
Have you checked for closed dampers? Not just registers ------dampers in the ducts, in the basement. If you in the part of the country where you need heat in the winter, often upstairs heat will go right through the first floor ceiling, so the upstairs registers do not have to be blowing out as much, and perhaps that coud be why some got closed down (IF they got closed down). [Note that at 5 feet up at the thermostat height on first floor, temp may be 72; but may be 77 or higher up at the ceiling, depending on height of ceiling, for example].
Have you actually put a thermometer in both a first floor register and a second floor register to compare temps coming out?
Does the second floor duct work come in from day some hot attic space and the registers are in the ceilings? Or, are the registers in the floors or baseboards?
Have you checked for closed dampers? Not just registers ------dampers in the ducts, in the basement. If you in the part of the country where you need heat in the winter, often upstairs heat will go right through the first floor ceiling, so the upstairs registers do not have to be blowing out as much, and perhaps that coud be why some got closed down (IF they got closed down). [Note that at 5 feet up at the thermostat height on first floor, temp may be 72; but may be 77 or higher up at the ceiling, depending on height of ceiling, for example].
Have you actually put a thermometer in both a first floor register and a second floor register to compare temps coming out?
Does the second floor duct work come in from day some hot attic space and the registers are in the ceilings? Or, are the registers in the floors or baseboards?
jim-connor
07-11-08, 08:33 AM
Contact your installer. They should have looked over the ducts before installation.
Codyy
07-11-08, 10:06 AM
Contact your installer. They should have looked over the ducts before installation.
Very much true. Duct system is supposed to be inspected and modified if necessary upon an upgrade or other installation.
Very much true. Duct system is supposed to be inspected and modified if necessary upon an upgrade or other installation.
HVAC RETIRED
07-11-08, 12:42 PM
I upgraded from a 3ton to 3.5ton unit. What are some signs I do not have enough returns in the house?
For cooling the SA & Returns work better near to, or on the ceiling.
Increase the amount &/or size of the upper level Returns.
You can put a fan blowing into the upstairs return(s).
As others stated, have every aspect of your duct system checked.
The ducts to each room should have their air velocity & CFM checked. The total CFM for a 3.5-ton system should not normally be below 1225-CFM, 1400-CFM is nominal airflow.
HVAC RETIRED - udarrell
For cooling the SA & Returns work better near to, or on the ceiling.
Increase the amount &/or size of the upper level Returns.
You can put a fan blowing into the upstairs return(s).
As others stated, have every aspect of your duct system checked.
The ducts to each room should have their air velocity & CFM checked. The total CFM for a 3.5-ton system should not normally be below 1225-CFM, 1400-CFM is nominal airflow.
HVAC RETIRED - udarrell
jsh1975
07-20-08, 05:43 PM
It was an issue with the tstat. I have an infinity tstat and you have to program the size of your a/c into it. The installer overlooked this step so when I looked at it it was setup for a 1.5 ton unit and not a 3.5 ton unit. As far as the return goes we took the front of the furnace off to increase the return it was getting and we moved up from 1137 CFM to 1400 CFM. Any suggestions besides cutting more holes in the house for an additional return?