Funny you mention the trunk line—I've seen a lot of folks jump straight to duct leaks or blocked vents, but sometimes the issue is actually with the balance of the system itself. Ever checked if your supply and return are sized right for both sides of the duplex? I know it sounds nitpicky, but if one side's getting way more airflow, no amount of taping or vent-blocking really fixes the core problem.
Also, about furniture over vents—yeah, that's a classic, but I've run into cases where the return vents are the real culprit. People forget about those and stack boxes or couches right in front, and suddenly the whole pressure in the system gets thrown off. Did you ever try using those cheap airflow meters to see if the CFM was way off between rooms? Sometimes the numbers are wild, and it points to something less obvious, like a damper stuck half-closed or even a kinked flex duct.
Curious if you ever looked at the static pressure or just went by feel? It's wild how much difference a little imbalance can make...
Had a customer last month who swore up and down their “fancy new thermostat” was busted because the living room was roasting and the bedrooms felt like a walk-in freezer. Turns out, they’d shoved an old recliner right up against the only return in the hallway—like, pressed so tight I had to wrestle it off. Static pressure? Through the roof. You could hear the blower motor wheezing like it just ran a marathon.
I’ve messed with those cheap airflow meters too, and sometimes the numbers are so far off you’d think someone was pranking you. One time, found a flex duct so kinked it looked like a boa constrictor after lunch. Folks always want to tape up a vent or close a damper, but if the trunk’s not balanced or the returns are blocked, you’re fighting a losing battle.
And yeah, feeling for airflow with the back of your hand is classic, but once you see what a little imbalance does to static pressure, you start carrying a manometer just to freak yourself out. It’s wild how much havoc a single couch or a stuck damper can cause…
You could hear the blower motor wheezing like it just ran a marathon.
That’s a perfect description—seen motors get so stressed from blocked returns they sound like they’re begging for mercy. Ever notice how people rarely think about furniture placement and airflow? It’s always “the system’s broken” before “maybe the couch is in the way.” I’m with you on the manometer, though. Once you start checking static pressure, you realize how quickly things spiral out of whack. Curious if you ever run into issues with oversized filters too—those can choke airflow just as bad as a recliner sometimes.
It’s always “the system’s broken” before “maybe the couch is in the way.”
Ain’t that the truth. I’ve lost count of how many times tenants swear the AC’s shot, but there’s a bookshelf parked right in front of the return. About the filters—ever notice folks buy those “allergen” ones thinking pricier means better? Half the time, they’re so thick the system can barely breathe. Ever tried convincing someone to use the cheap ones instead? That’s always a fun conversation...
About the filters—ever notice folks buy those “allergen” ones thinking pricier means better? Half the time, they’re so thick the system can barely breathe.
Isn’t it wild how marketing gets us? I used to swear by those “premium” filters, but after my system started wheezing like an asthmatic cat, I switched to the cheap ones. Honestly, I can’t tell the difference in air quality. Do those expensive filters actually help, or is it just peace of mind? Also, why is it always the biggest furniture that ends up blocking the vents?
