leaking ducts allowing air into system.
the middle vents only supply air from the ac unit using a separate in dash fan. the floor and defrost vents come only from the heater
Air conditioning unit has iced up. Don't use it for a while and it should come right
Yes, gnats can come out of dirty air vents. Gnats can actually come from anywhere. They are very pesky creatures.
heater fan broken.
The heater may not be on - but the fan still blows air through the vents when they're open !
something has to be blocking the vents.
So it has something to heat and blow back out, thus, heating your home. The stuff coming out of your vents has to come from somewhere..
3
Compressor not operating.
Steam may be coming out the air conditioning unit if the engine is overheating. The best thing to do would be to shut the vents before any hazardous fumes begin to come out.
There should be at least a 12 degree split between the incomming air and the air comming out of the vents.
To improve airflow in your home using floor vents with fans, place the fans near the floor vents to help circulate air more effectively throughout the room. This can help distribute cool or warm air more evenly and improve overall air circulation in your home.