One more A/C Question?

Question

If the a/c is working properly what should be the temperature of the air coming out of the vents? And what factor play a role in duct temperature I've been having some problems with the a/c not blowing cool enough and am trying to narrow it down. Also does the temperature outside factor on the temperature the a/c can blow to or no? Thanks nick

Alright if the filter is dirty how do I go about changing that? Should I just go up to the auto parts and they will tell me how to do it.

Answer 1

Systems vary in design but most systems will give about a 45 to 50 degree temperature drop and will have a maximum cold temperature of 35 to 40 degrees.

This means an outside temp of 100 will result in vent temps of 50 to 55,

90 outside will give vent temps of 40 to 45

80 degrees and below outside will give vent temps of 35 to 40

an important thing to consider is a closed car in the sun can have temps as high as 130+ degrees so using inside air (recirc) could give vent temps as high as 80 to 85 degrees.

Always put the windows down for a few blocks and use outside air under these conditions until the interior is at the same temp as the exterior.

Answer 2

The duct temperature is affected by the temperature outside. If it is 90 outside, and you have R134a, look for 45 out the ducts, with the AC on high, set to the panel vents. The outside temperature is used to guage the high side pressure, which should be about 100 psi more than the ambient temperature. For example, on an 85 degree day the high side should be 180 psi to 190 psi, at idle.

Answer 3

I have seen a gauge on my car and it read 45 degrees at the vents on high. Problems come from low refrigerant in the system. Belt slippage, blend doors not opening up or the heater doors are leaking heat into the system when the A/C is switched on. Many other things, leaking system, poor compressor, slipping clutch, blocked filter with dirt in the system or bad pressure switch.

Answer 4

outside air temperature will effect the outcome of the temperature coming out from the vent. if the engine temperature or a/c condenser get hotter than normal,the a/c temperature will change. if the evaporator is frozen( clogged drain plug) or blocked( fins fill with debris or hair), temperature will change. if the temperature blend door is not seal,you will get different temperature.

Answer 5

You need someone with a "manifold gauge set" to hook it up and read the low side of your a/c system. That is the side that does the cooling and can tell you if you need to add refrigerant. I don't know what it would cost to have a shop do it. Pretty simple 15 min. job. It's the only way to really know.