View Full Version : Low air flow from register
sgoodman73
Aug 15, 2007, 04:46 PM
Got a big problem I had a A/C guy come out twice now I have very little air flow coming out of my registers. He checked the whole system and said everything was working fine that I probably had a hole in the duct work, went under the house for 4 hours that was fun but no hole there was some condensation on the main branch coming under the house don't know if that helps or not. I also went up in the attic to check the intake tubes they where clean and hooked up with no holes in them. He checked the blower and said it was set on high there was nothing he could do. He suggested I just get a bigger unit I have a 1500 square foot house and I think it's a 2 1/2 ton unit is that big enough I have the same problem in the winter not allot of heat either checked it the other day it was 102 outside and the vent the farthest away from the unit was blowing out 65 degrees if you stick your face in front of it, but if you put a piece of paper in front of the register it won't ever move. Please help its hot in here.
acetc
Aug 15, 2007, 04:55 PM
It may have a dirty evaporator coil dirty filter , or low on refrigerant . If the coil ices up then it will get very little air flow and if dirty it will need to be washed. If you remove the blower in the furnace you can normally see through the furnace to the coil with a flash light to see if it is dirty. Good luck, Mike
esquire1
Aug 15, 2007, 04:58 PM
Just went a call yesterday with same problem as yours. It was the intake side of the coil (The side coming from the return) It was 95% clogged. Lucky I could get to that side without removing the coil (evaporator) Finally he had air flow and a cool house again. Probable cause of problem was the folkes have 2 very furry cats inside and not changing filters on a regular basis.
sgoodman73
Aug 15, 2007, 05:01 PM
[QUOTE=acetc]It may have a dirty evaporator coil dirty filter , or low on refrigerant . If the coil ices up then it will get very little air flow and if dirty it will need to be washed. If you remove the blower in the furnace you can normally see through the furnace to the coil with a flash light to see if it is dirty. Good luck, Mike[/QUOTE
I checked coils under the furnace the weren't frozen and seemed clean got band new filters in it and the A/C gut said there where no leaks and I was good on freon. THe low air flow problem is with heat and ac what would cause that.
sgoodman73
Aug 15, 2007, 05:04 PM
Thanks ill check that what would be the best way there is a panel on the side of the coils would that be the best way to check it
acetc
Aug 15, 2007, 05:17 PM
Some insulation may have come loose in the plenum (sheet metal box under coil) this is a down flow installation. If the insulation comes loose it will block air flow.
esquire1
Aug 15, 2007, 05:21 PM
Thanks ill check that what would be the best way there is a panel on the side of the coils would that be the best way to check it
Yes
sgoodman73
Aug 15, 2007, 06:22 PM
Hey cleaned the coils used a vacum with the brush attachment guess that's the way you do it it was a little dirty not to bad also looked down into the exhaust part the best I could see didn't see anything blocking it still no air flow in the whole house. Had the cover off looking around with the blower on how hard should it be right there wasn't as hard as I expected it to be could it be stopped up on the furnace side
acetc
Aug 15, 2007, 06:30 PM
Can you run the blower with the blower panel off to check air flow, and is there any thing in the blower wheel?
sgoodman73
Aug 15, 2007, 06:32 PM
I can hold down the safety switch but the way its made you can't even see the blower I don't know how you would even get it out looks like the vent pipe runs in front of it
acetc
Aug 15, 2007, 06:35 PM
Sounds like a Carrier, can you take a mirror and flash light to inspect the blower wheel?
Can you run the blower and leave the cover panel off the coil and see if you get the same amount of air .
sgoodman73
Aug 15, 2007, 06:39 PM
It's a tempstar what should I look for I can see it running with a mirror cleaned it out already forgive my ignorance
acetc
Aug 15, 2007, 06:46 PM
If you have duct that is insulated on the inside under the house , you could have loose insulation, depends on how your system was installed, some contractors run a sheet metal trunk line insulated on the inside down the center of the house with take offs that may be insulated on the outside, We're grasping at straws but you have to go through the process of elimination. Hang in there, Mike
Look for any thing in the blower that should not be there.
sgoodman73
Aug 15, 2007, 06:54 PM
Best I can tell its just sheet metal ductwork with no insulation when I was under the house I did notice condensation on the main branch could this be anything I would call somebody but like I said already had 2 guys out said everything was fine just no airflow into the house . I even grasped at straws and sealed the coil box just to make sure I didn't have a leak there keep giving me straws ill try anything. One thing might help might not some rooms have better flow than others one bedrooms seems pretty good but the one right next to it has hardly anything and its on the same branch and closer to the unit
acetc
Aug 15, 2007, 06:59 PM
Did you get a lot of air out the coil when you run it with the coil cover off? And the blower door in place , if so then this would indicate that the problem is in the duct (restriction)
sgoodman73
Aug 15, 2007, 07:01 PM
Seems like it blew pretty good don't know if it was right or not on the blower you can look it to she squirel cage should the be something covering that I can see the blades turing
acetc
Aug 15, 2007, 07:07 PM
I am thinking that the condensate that you saw on the duct work might be a clue to this problem, if the main duct is insulated on the inside and came loose it would cause the duct to sweat where it came loose, they normally glue insulation to the inside of the rectangular duct work if it is under the house or in the attic, if there is a branch duct near this area you might pop it loose and look inside the duct with a mirror and flash light. Still grasping at straws,
sgoodman73
Aug 16, 2007, 03:13 PM
Noticed on top of the coils when I cleaned the there is a metal bracket on top of the coils if you take it off you can see into the duct work if I take that off would it give me more air flow or would it be too much airflow and not cool down, also I used a vacuum with a brush attachment to clean the coils they where a little dirty not to bad but is there a better way to clean them somebody said wash them out but wouldn't the water go down into to duct work.