A/C Temperature?

[trook]

For those of you with cabs, what is the temperature of the air coming out of your a/c vents? My new JD 5075e is only blowing 70 degrees. When I advised my dealer something was wrong with the a/c, they checked it and said it is "cooling". It is comfortable in the cab with the fan on 1 or 2, but the outside temp is only 75. They said nothing is wrong with it. The return line is cold and wet, but I can't help but think the temp should be MUCH cooler. What's going to happen with the outside temp reaches 95 degrees???

For comparison purposes, the air temperature in my truck and wife's car is around 42 degrees.

 

[tony Cecil]

I`m having the same problem, same explanation , so I think the truck is right and in my case the little valve looking thing is white with frozen vapor, so I think something is wrong there...Good Luck Tony

 

[trook]

What make and model tractor do you have?

 

[jd110]

RUle of thumb I was taught; temperature from vents should be AT LEAST 30 degrees cooler than outside air temperature. Are you sure the heater valve is closing completely? Try feeling the heater hoses where they enter the cab. If they are warm, try pinching one closed with a clamp and see if the temperature in the cab improves. Also be sure the radiator and condenser is clean. Even if it appears clean, dirt can be in the fins and not visible. Place your hand in front of the radiator with engine running half throttle or faster, you should feel a strong flow of air being drawn through the radiator.

 

[grsthegreat]

hmmm, im not sure if the problem isnt associated with the fact that the outside temp is so cool already. Ive never run mine in the winter except far a few times when the condensation in the cab was an issue. Ive since fixed that issue with opening the outside air vent in winter while running the heater.

I can tell you that in the summer, while its 97F outside the interior of my cab is darn right chilly. Ive never checked it with a thermometer, but i do have to turn fan to lowest setting or i get chilled. It SUCKS when i have to leave the cab.

If i think about it tomorrow, ill see what mine does , however its only supposed to get to 49F tomorrow, so it may be too cold to tell.

 

[jenkinsph]

I would expect to see about 45 degree air at the vents with 75 degree ambient temperature. If your tractor is putting out 70 degrees at the vents you have a problem. The first things I would check are the front condenser and the evaporator in the roof, make sure both are real clean.

I would also add that most AC systems will cool the evaporator coil down to a cut off temperature around 40 degrees, this is to prevent the coils from freezing up. In this set up the air blowing over the evaporator coil can't get much lower than 45 degrees. When the cab is hot after being parked in the sun it will have to cool down gradually so the air temperature at the outlets may be close to 60 degrees but should continue to fall as the air temperature lowers and the air is exchanged.

 

[trook]

Guys, I should have added that this is a brand new tractor. I have done about 2-3 hours worth of work. The radiator and condenser are spotless.

I had the dealer check the a/c last week because the air was cool but not cold when I received the tractor. He said it was "cooling" and normal. I don't dare open the roof as I have heard stories about tearing a seal. I checked the temp coming out of the vents this afternoon on a 75 degree day. The vent temp was no better than 70 degrees, sometimes a little warmer.

grsthegreat, I have heard something similar to what you are saying about the ac not working well until the outside temp rises a little. However, auto ac's seem to work very well with 70 degree temps. Are tractor ac's different?

 

[grsthegreat]

dont know. Ive never run an air cond till it gets into high 80 myself.

Im pretty sure my a/c wont work very well with 49F outdoor temps, but ill check it out tomorrow.

 

[grsthegreat]

i would think there no different than auto a/c units. i mean, how much different can they be. there both just basic automobile units.

 

[jenkinsph]

Guys, I should have added that this is a brand new tractor. I have done about 2-3 hours worth of work. The radiator and condenser are spotless.

I had the dealer check the a/c last week because the air was cool but not cold when I received the tractor. He said it was "cooling" and normal. I don't dare open the roof as I have heard stories about tearing a seal. I checked the temp coming out of the vents this afternoon on a 75 degree day. The vent temp was no better than 70 degrees, sometimes a little warmer.

grsthegreat, I have heard something similar to what you are saying about the ac not working well until the outside temp rises a little. However, auto ac's seem to work very well with 70 degree temps. Are tractor ac's different?

How long did you run the AC before checking the temperature at the outlets?