miss match cooler

[rcac101]

Hi everyone well im back in the field full time and on my first refrigeration disaster.
So a walk-in cooler im working on with a Bohn, m#ADT052AJ R22 txv I looked up the M# seems to me its a 5200btu, evap coil. Well someone installed a used Heatcraft condensing unit M#MOH005D72C a 134a 5970-7790 BTU cant match m# due to age of equipment. OEM compressor m#ART82C1-CAV-02 which i cant find data for anywhere yet. So im thinking swap out txv and i should be ok. any help would be great.

[markettech]

Hi everyone well im back in the field full time and on my first refrigeration disaster.
So a walk-in cooler im working on with a Bohn, m#ADT052AJ R22 txv I looked up the M# seems to me its a 5200btu, evap coil. Well someone installed a used Heatcraft condensing unit M#MOH005D72C a 134a 5970-7790 BTU cant match m# due to age of equipment. OEM compressor m#ART82C1-CAV-02 which i cant find data for anywhere yet. So im thinking swap out txv and i should be ok. any help would be great.

This is a tricky one.

Your ART82C1-CAV is a 5,000 Btuh compressor at 25F/110F designed for R22. You are correct in stating the coil is a 5,200 Btuh evap at 25F SST.

At first glance it appears your coil is fairly closely matched with the compressor, although I like to see the compressor having slightly more capacity than the coil's load.

Here's the tricky part. If you truly have an R134A condensing unit with an R22 compressor installed on it......I would be very concerned about the condenser being sized properly.

Honestly, I'm not sharp enough on the engineering side of things to offer much assistance with even attempting to calculate whether or not the condensing unit itself will work with your desired application. Maybe someone like icemeister or Powell can help you there.

Whatever you do, I would NOT put a 134A TXV on it.

[ammoniadog]

I didn't try to run any of the numbers you had, but I would double check the part about the R134a. That is a really uncommon refrigerant for a walk in cooler. Usually 134a is only used on the small stuff. If the condensing unit/compressor is really designed for R12, I would find a different replacement refrigerant to run in it. R134a is a pretty crappy refrigerant. I wouldn't use it unless the system was actually designed for it.

As for your TXV, as long as you size it to the condensing unit capacity (and of course match it to your refrigerant) you should be ok.

Was this thing trying to run when you found it?

[icemeister]

That the Bohn condensing unit model number indicates R134A is irrelevant now because the compressor is rated for R22. The evaporator is rated at 5200 Btuh at a 10°F TD, so for a 35°F box, it would match up fine with a compressor with a capacity of 5000 Btuh at 25°F SST. (TD = Box Temp - Evap Temp)

So far, all looks OK... so what sort of problems are you having with this system?

(I'm assuming there's R22 in this system. )

[ryan1088]

Franken-cooler has the wrong txv? I love how most of the numbers on txvs are never legible when you need it.

[markettech]

That the Bohn condensing unit model number indicates R134A is irrelevant now because the compressor is rated for R22. The evaporator is rated at 5200 Btuh at a 10°F TD, so for a 35°F box, it would match up fine with a compressor with a capacity of 5000 Btuh at 25°F SST. (TD = Box Temp - Evap Temp)

So far, all looks OK... so what sort of problems are you having with this system?

(I'm assuming there's R22 in this system. )

So Btu's are Btu's and as long as the condensing unit (condenser) is sized for 5,000 Btuh, then it's all good.....is that what you're saying?

[icemeister]

So Btu's are Btu's and as long as the condensing unit (condenser) is sized for 5,000 Btuh, then it's all good.....is that what you're saying?

Essentially, yes. The evaporator doesn't care what refrigerant you use. It only depends on the temperature difference or TD. Same goes for the condenser. It'll do the same job with R22 as it did with R134A.

The truly important factors here are the compressor and the TXV.

[markettech]

Essentially, yes. The evaporator doesn't care what refrigerant you use. It only depends on the temperature difference or TD. Same goes for the condenser. It'll do the same job with R22 as it did with R134A.

The truly important factors here are the compressor and the TXV.

Makes perfect sense now that you've explained it. Thanks.

[rcac101]

Thanks for all your help some how this had a 134a sticker on it well I was able to cross -ref the comp and its a match. Oh the system was a block of ice as i thawed it i noticed the green txv and recalled the 134a sticker. Im the 3rd guy on this and i bet its got the wrong gas in it

[ryan1088]

Thanks for all your help some how this had a 134a sticker on it well I was able to cross -ref the comp and its a match. Oh the system was a block of ice as i thawed it i noticed the green txv and recalled the 134a sticker. Im the 3rd guy on this and i bet its got the wrong gas in it

I don't know that I would fault anyone for putting 134 in something that was marked as such. If it is indeed 22, whoever changed it should bear the shame. I paint the heads of my compressors and have our sign shop make me labels just for that reason.

[markettech]

I don't know that I would fault anyone for putting 134 in something that was marked as such. If it is indeed 22, whoever changed it should bear the shame. I paint the heads of my compressors and have our sign shop make me labels just for that reason.

Yep, nothing more frustrating than having to basically re-engineer a system before being able to service it.

[rcac101]

So the local crackhead used to to b a refer man ....bar owner wanted cheep labor i guess he got it... im done with Cooler... beer is at35 deg f...will not be defeated!!