Walk in freezer R448A

[Bworth74]

Received a call on this walk in freezer another company installed. System is remoted 2 floors above box. R448 refrigerant with -10 setpoint for Freezer. Looks like this unit has an MOP txv valve at 35 psig. Has a headmaster valve for 225 psig. Unit is actually at temp but looks as if in the colder mornings and nights it may be low on charge causing this iceing issue. I will have more info tomorrow. Just wanted some initial thoughts.

[pecmsg]

R-448A is a replacement for R-404A

Treat it as the same.

Is it low on charge? Clear the glass. 225# headmaster is fine!
Are you aware how a headmaster works?

That ice tells me its coming out of defrost a little early possibly a bad heater.

[Bworth74]

Yes I’m familiar with headmasters, but looking at the ice formation around the txv and inlet of coil seems excessive like it was low on refrigerant enough to where the headmaster couldn’t keep pressure up. I will know more tomorrow when I have another guy so I don’t have to go back and forth 2 stories since the location is a pain.


Sent from my iPhone using Tapatalk

[pecmsg]

Yes I’m familiar with headmasters, but looking at the ice formation around the txv and inlet of coil seems excessive like it was low on refrigerant enough to where the headmaster couldn’t keep pressure up. I will know more tomorrow when I have another guy so I don’t have to go back and forth 2 stories since the location is a pain.


Sent from my iPhone using Tapatalk

Could be low
Valve out of adjustment
Garbage in the strainer (Hope not being hard soldered..Bring an extra valve just in case)
Not properly charged for the headmaster .......now its cool at night.

[Bworth74]

Could be low
Valve out of adjustment
Garbage in the strainer (Hope not being hard soldered..Bring an extra valve just in case)
Not properly charged for the headmaster .......now its cool at night.

Yes it was installed in August in Texas so this is its first winter. It’s been getting high 20’s low 30’s overnight for a week or so now.


Sent from my iPhone using Tapatalk

[pecmsg]

Now the question is.........(If its low)

Is there a leak or just not charged properly to begin with?

[Bworth74]

Now the question is.........(If its low)

Is there a leak or just not charged properly to begin with?

Lol, I was just thinking that. Guess a leak check is in place.


Sent from my iPhone using Tapatalk

[pecmsg]

I would get there early in the morning............
If it only takes maybe a lb with a micro channel your probably good.

If its actually short well have fun!

[pecmsg]

Post pics of the condensing unit

[Bworth74]

Post pics of the condensing unit

Ok I will do that tomorrow


Sent from my iPhone using Tapatalk

[dave sulz]

Correct me but I charged a big walking in summer with headmaster. Cleared the glass but didn't add an extra amount for winter. Giant box filled w/ bannanas. Added and working nice but no ice just not cooling.

[VTP99]

You have to add the additional charge for the head pressure control valve to be able to flood the condenser.
Oh, and you should start a new thread.

[2sac]

You don't think that's steam freezing?

[AngryReferGuy]

Received a call on this walk in freezer another company installed. System is remoted 2 floors above box. R448 refrigerant with -10 setpoint for Freezer. Looks like this unit has an MOP txv valve at 35 psig. Has a headmaster valve for 225 psig. Unit is actually at temp but looks as if in the colder mornings and nights it may be low on charge causing this iceing issue. I will have more info tomorrow. Just wanted some initial thoughts.

how is this defrosting ? hot gas or electric ?? how many times a day and what is the duration ?? is there any termination ? are the fans shutting off in defrost ?? more information is needed

[Bworth74]

Sorry still scheduling with customer to get in and make a good diagnosis. I will post as soon as I have the information.

[VTP99]

So did you calculate the winter charge per Sporlans bulletin ?

[Bworth74]

So did you calculate the winter charge per Sporlans bulletin ?

I did not. Still evacuating where can I find that info please.


Sent from my iPhone using Tapatalk

[VTP99]

R404a is a great refrigerant and probably half the price of R448a. A third the glide as well.

[Bworth74]

R404a is a great refrigerant and probably half the price of R448a.

Almost half price at United Refrigeration. R448A is definitely more expensive for sure!


Sent from my iPhone using Tapatalk

[WT70]

Something interesting to note that I see when people start working with a new refrigerant.

They seem to forget basic refrigeration diagnostic methods

Charge, Superheat, operating pressures, defrost lengths and proper termination, etc.

I have done a lot of work with R448a both Racks and Self contained/conventional. It runs almost the same as R22, but lower discharge temps.

Go through from start to finish and make sure it's all operating correctly, I bet you will find the problem along the way. It's just a freezer.




Sent from my iPhone using Tapatalk