R410 air handler with R22 condensing unit

[Jupiter Trch]

I will be going back tomorrow for the 2nd time on a new install and would like some help from you pro's!
I sold a client a 2 ton R22 air handler to go with his 2 ton straight cool XL14i condenser and we mistakenly installed a 3 ton R410 air handler (Trane) and had a call back for not enough cooling the next day. We then replaced the air handler again with the correct size but still using the R410a expansion valve. When I questioned why not replace the expansion valve I was told by management that it will work fine and no need to replace valve. And now after a few days later I find out I am going back and I have a feeling that my problem is going to be that the valve should be replaced to use R22. As I don't really know why other than its wrong. What can I tell my management to explain why it's wrong? And if it is ok to do I will just drop my argument and move on.
Thank you in advance for your help.

[beenthere]

It will flood the evap. The pressure in the evap is not high enough to counter the charge in the bulb. The pressure in the external equalizer is what pushes back against the bulb charge. Opposite happens when you use an R22 TXV on an R410A system, it under feeds.

[BaldLoonie]

It is going to be the valve. That was made clear by everyone in your last thread on the job.

[Jupiter Trch]

It will flood the evap. The pressure in the evap is not high enough to counter the charge in the bulb. The pressure in the external equalizer is what pushes back against the bulb charge. Opposite happens when you use an R22 TXV on an R410A system, it under feeds.

Thank you for the answer, i appreciate it.

[Jupiter Trch]

It is going to be the valve. That was made clear by everyone in your last thread on the job.

I expected an answer like this as well. I realize it won't work correctly but I wanted to know why it won't work correctly. The reason for the new thread was to make it clear to me and drop all the other stuff about the job. So thank you for the useless and obvious info and for taking the time to dig and point out that there was another thread, that really helped!

[Brent Ridley]

Did you install a Trane Hyperion AHU? If so, check the EEV board. There is a dip switch to swap from R410A to R22. No need to change the whole valve or stepper motor.

Change the switch, cycle the power, and restart.

[Jupiter Trch]

Honestly I can't tell you that yet but I am going there in a couple of hours and find out but i believe it is going to be the GAM air handler. Thanks for the input I will check it out.

[toocoolforschool]

What we have here is as failure to communicate.

[ar_hvac_man]

What we have here is as failure to communicate.

lol. Some men, you just cant reach

[ar_hvac_man]

I bet the 3 ton ah would have worked by simply changing the txv to r22. The route taken seems backwards to me

[Mr Bill]

I bet the 3 ton ah would have worked by simply changing the txv to r22. The route taken seems backwards to me

+1.

[jdblack]

I bet the 3 ton ah would have worked by simply changing the txv to r22. The route taken seems backwards to me

+2



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[Jupiter Trch]

Seems the problem is the length of the line set. Measured the line set at 375 foot with 10-12 foot vertical rise. Found the liquid line at 67 degrees at the air handler. Spoke with Trane tech support and be said max 200 feet. He said without moving the condenser closer the only other thing I could try is lowering the fan speed which I did and it did help but not a lot. Explained that to the client and of course he gave me "we'll the original system worked fine" so now we are moving the condenser if the lowered fan speed does not work. And the Trane tech support said that having a smaller evap coil is actually helping me.