[Dogbones]

I have a room at a walk in cooler and I have a room at 34 degrees, I always see recommended superheat for pretty much everything at 8-10 but the sporlan pro app suggests 13* superheat.


No real problems with the temps in this room but there is a giant block of hard/clear ice on every evap after the EEV and on the distributors.

The temperature/ lsv for each unit is controlled by a plc and by terrible design if it is .1 above setpoint it turns on and .1 below and it turns off. Which means these units pretty much click on and off every few minutes. I'm thinking ill drop the SH to 10 or lower and that way the evap will drop further below setpoint than it currently does and have a little bigger of an off cycle. If that doesn't work i'll probably have the programmer put in a deadband


I've been curious, when it comes to the superheat which I should go with the 8-10 or 13 and if it even matters and why.

Thanks yall, i really appreciate all the help and information you guys give. :grin2:

 

[pecmsg]

The SH at the compressor is more important, Maintain 20 - 40° 6" from the pump.

 

[TechmanTery]

There are 2 SH's that we use for the loside.
One is the 'evap' SH and the other is 'compressor' SH or Total SH.

Sometimes the OEM specifies the evap SH.
ALL THE TIME the Comp OEM specifies the Comp SH. Do as pecmsg said, by adjusting the SH for the longevity of the comp. The evap SH comes in a distant 2nd place.

 

[pecmsg]

.2 dead band will kill that equipment

 

[Dogbones]

I have 26-30* SH at my compressors, was just wondering if it made more sense to have the evaps at 8-10 vs 13. I always see 8-10 everywhere I look but I never see why or the benefits of 8-10 vs other numbers. A lot of numbers will work but I just wasn't sure if there was more to it than that.

.2 dead band will kill that equipment

Why is that, what should I be worried about?

Each unit is controlled by a vfd and never turn off unless the unit is defrosting, but the frequency lowers when the evap is at temp.
Compressors don't turn off or short-cycle, this is only one room part of a bigger system

I changed the SH to 10 for now and it's getting ~1* below setpoint, much better than the .1 - .3 before so it isn't getting liquid all the time.

 

[pecmsg]

Exactly what type of system is this set up on?

 

[Dogbones]

decent sized cooler / cold storage plant that I inherited

6 rooms 2 docks and a couple hallways
34 evaps between 4-12ton controlled by a PLC

things like this kinda just sit in the back of my mind and bug me, but outside of this website the information seems pretty hard to come by

 

[pecmsg]

Are these 12-Ton systems piped together?

 

[pecmsg]

We deal with HP in refrigeration not tons

 

[VTP99]

The lower the superheat the more capacity from the coil.

 

[Dogbones]

The lower the superheat the more capacity from the coil.

I get that. I was just wondering if I'm already getting to temp with 13* superheat, would there be any reason to change it to 8-10 or any reason to leave it at 13. Either way it's going to hit temp, but I was just curious if one would have benefits over the other.

 

[pecmsg]

I get that. I was just wondering if I'm already getting to temp with 13* superheat, would there be any reason to change it to 8-10 or any reason to leave it at 13. Either way it's going to hit temp, but I was just curious if one would have benefits over the other.

Yes

The compressor SH!

 

[VTP99]

I get that. I was just wondering if I'm already getting to temp with 13* superheat, would there be any reason to change it to 8-10 or any reason to leave it at 13. Either way it's going to hit temp, but I was just curious if one would have benefits over the other.

If you can run at 8° superheat and still be safe at the compressor it will be more efficient.

 

[Dogbones]

Yes

The compressor SH!

Sh at compressors didnt drop below 25* even with low load, but i will make sure to keep boths eyes on it.

If you can run at 8° superheat and still be safe at the compressor it will be more efficient.

Sweet! Thanks

 

[pecmsg]

Sh at compressors didnt drop below 25* even with low load, but i will make sure to keep boths eyes on it.



Sweet! Thanks

25* at the pump is fine.
Don’t let it go below 20*

 

[Dogbones]

25* at the pump is fine.
Don’t let it go below 20*

Yes sir! Thank you guys.

 

[VTP99]

Now while you're here go ahead and apply for Pro Membership