The duct work probably runs through an area that is hot and humid, i.e. attic space, and it isn't insulated.
is your fan running in the correct direction? are any of your ducts blocked?
from the air in the vent to the air in the room
The air conditioner is low on refrigerant.
The A/C extracts water from the air.
the air coming from the vent is warm
It's somewhat cold. It's just very little cold air coming out. Can't hear the vent blow the air as well.
A rotten egg odor may indicate a dead rodent or animal in or near the ventilation system, whether in a house or car.
you cant so do not turn it on or else your house will catch on fire
The air from the vent should be 18 to 22 degrees F lower than the temperature of the air going into the return.
Install an automatic air vent on the line
As water drains, it displaces air in the pipes. If the vent or vents in your house are clogged up, the air must find another way out, which could be another drain in your house.
According to portable air conditioning suppliers, Mobile Air, all air conditioners have to be vented. But, there are different ways to "vent" the heat. The first way to vent is using water-cooled air conditioners. This type of unit uses water to cool the heat generated and requires a water source and drain. Mobile Air's website, , states that water cooled AC is required if the ambient temperature exceeds 115 degrees F. The second way to vent the heat produced is by using air. Air venting is done by using duct work to vent the hot air outside or by placing the unit outside to vent right into the air. This type is a bit more portable than water cooled.