Automotive Air Conditioning Information Forum

Hi everybody, my apologies if this is a really stupid question, but I've done some googling and haven't found an answer. I am new to working on AC of any type and I am trying to install an old under dash evaporator unit in a rather tight space. The unit has an expansion valve and bulb sticking out of the top with both the inlet and outlet pipe. After much flipping and checking it seems the most convenient orientation for my application would be to have the whole unit upside down. This would make both the inlet and outlet pipe pointed to the floor. I typically see these units with both pipes pointed horizontally, I've never seen one with them pointed down.

Would this cause issues? I know condensers have a right side up, but I haven't read the same for evaporators.

Thanks.

If you're referring to the evaporator core and case as an assembly, it must be installed in the car with the drain tube(s) facing down so that the condensate will drain out.

As for the refrigerant lines facing down, I'm not sure, never having done that myself. An issue that I can imagine is that refrigerant oil might pool in the evaporator, subsequently starving the compressor of lubricant and causing it to fail at some point.

I would make an effort to install it in the correct orientation, though, because that's the way it was originally designed.

Partly correct. Drain tubes need to be down angled to allow water to flow out. Having the evap straight down with blower under the evap. Will allow water to flow back in the motor and blower wheels.

That's if I'm reading the question correctly.

The blowers are located on the back, and I would drill new drain tubes on the bottom of the evaporator housing and run the lines out of the car accordingly. This is more about the refrigerant lines,

JohnHere wrote:As for the refrigerant lines facing down, I'm not sure, never having done that myself. An issue that I can imagine is that refrigerant oil might pool in the evaporator, subsequently starving the compressor of lubricant and causing it to fail at some point.

I would make an effort to install it in the correct orientation, though, because that's the way it was originally designed.

Seems like wise advice, sounds like its not worth messing with.
Thanks guys

Placing a 90 on the suction so it points down is not an issue. Exp and liquid and be rotated to achieve the same. Only is condensation from the coil dripping back on the blower ti you tilt it too much.