Any HVAC guys here? (Calibrate used unit)

[Shadow_storm56]

So long story short I'm a bit of a tinkerer and also a farmer so have to know many skills anyways.... I needed a new cooling unit to keep my cranberry room around 40-50F for packing time and for cold storage of certain things that don't like the temp of the normal coolers. I found a great deal online for a used unit a guy had as a spare and just wanted to get rid of so it was cheap. Took the risk and gave it a try, it was charged up too so I just pumped it down, took it apart and reassembled it. The compressor works great but I can't get the cooling coil to really load it down. It had an r22 tx valve and the compressor/gas is r404a so although generally possible it's hard to tune that valve for 404a.

Sofar I can get it to load down a little bit but I find my capillary tubes turn into a ball of ice and I'm not sure if that matters but I'm curious.

Compressor side works great it's just the evaporator side that I can't get tuned right.

 

[Tughill Tom]

Just a WAG, does it have a Hot Gas By-pass set up on? Also some TX valve heads can be changed to match the system gas and operating temps.

 

[Shadow_storm56]

Just a WAG, does it have a Hot Gas By-pass set up on? Also some TX valve heads can be changed to match the system gas and operating temps.

Nope just the TX valve. I ordered one online for that gas.

 

[Shadow_storm56]

Seems the current one is either too far closed or too far open. Dosen't want to get in the right zone.

 

[thebicman]

I assume you have the tools and the knowledge to install the newer unit? You installed a new drier and evacuated the system?

 

[Shadow_storm56]

I assume you have the tools and the knowledge to install the newer unit? You installed a new drier and evacuated the system?

Didn't change the drier as the evap and the condenser were a pair and are still a pair.... guy had it hooked up, wired up and ready to go sitting on a pallet as a spare. Had It hooked up so he could occasionally test it to be sure it was ready to go.

Drier does not have a temp change across it and yes the system was vacuumed. It works good now it turns out although in alot of occasions an r22 tx valve will work in 404a... this was not one of thoes occasions.... or the valve went bad over time.

I borrowed a proper 404a valve from a unit that's idle for the next few months anyway and now we're good.

It was set to a superheat of 20 to help not pull out too much humidity but was no issue to change to the correct value for this unit.

Now I just gotta order a new one for the other unit.

So we're all good.

I enjoy learning new skills, was a cheap unit as it was in the guys way and all the tags except for gas type and motor specs had gotten rubbed off so no one wanted to buy somthing with no specs so it kept getting cheaper. Great unit to learn on and actually the compressor is in A1 condition.

Ironically one of my other units has the identical condensing unit which I was able to determine from what numbers did remain so I have all the specs now.