Beer walkin problems....

[coolerfixer]

Brand new beer cooler, roughly 30' long, 8' wide and 10' high. I was called in because the low bid out of area contractor was clueless I guess. Woulldn't pull down below 42 degrees after several days. Both evaps frozen with 2" thick frost on the bottom third of the coil. I defrosted the coils to find the txv sensing bulbs coiled up all nice and pretty, the way they come out of the box. So, I strapped them on. Easy fix right? Wrong. SH had obviously never been set. So I hook up my YJ DRSA to see 35 degrees of SH at the suction outlet on both evaps. Hmmm. I ended up backing the txv's all the way out, never could get better than 26 deg SH at the evaps. To make things even more fun, the cond unit is on top of the cooler, and is now unaccessable.They built a lovely backbar to block the access. Sheesh. Pumped the system down using the stat to close the LL solenoid. Put in a sightglass and an access port on the liquid line so I could at least see a little of what was going on.Stuck the vac on to pull out as much air as possible.

So here are the important numbers

Climate control cond unit m/n HWN020
Climate Control evaps (2) m/n LSC070AHK
sporlan SQE 1(3/4)- vc txv with # 1 cartridge
R-22 nozzle L-1/3
sightglass shows full column of liquid
suction 37.4 psig
liquid line at 184 psig
26 deg superheat

It's the end of a 20 hour day, I'm fried and the only thing that I can think of is wrong nozzle.
Planning to call Heatcraft in a couple of hours. Whadda you guys think?

[hvacmd2002]

Just did some real quick numbers. Gotta fly out the door in a sec. Your unit will do 14330 @ 20 degree evap. In URs catalog, an 8x30x8 box needs 14200-18000 btu. But I'm sure you have glass doors, which the chart doesn't take into account. Hmm...sure you have enough HP there?

Maybe someone with a little more time can run the load

[powell]

coolerfixer,

The equipment in this box is undersized. TXV's wide open, high superheat and high temperatures are the symptons.

A typical 8 x 30 x 10 beer cooler requires about 25,462 btuhs. If it's a display cooler with glass doors, lets say 11, the btuh requirements is about 37,208 btuh.

The equipment you have: HWN020 Climate unit, water cooled, pumps 16,760 btuhs at a +25 SST. This equates to a 11.7 TD matched with the 2 ea LSC070 evaps.

You should have the customer call his low bidder or be prepared to buy more equipment from you.

[coolerfixer]

No display doors. Pretty much a tap room. to store kegs and bottle backstock. Very limited entry to add heat. Imperial Mfg made the box and sized the equipment. Spoke with them and they stand by their sizing. Talked to engineering this am. Thinking that maybe Mr. Lowbid charged with 404a instead of 22. Will be heading over to recover charge, evacuate and charge with fresh 22. I'll report back.

[cretan]

What ambient temps at the condensor?

[coolerfixer]

What ambient temps at the condensor?

It's a closed loop cooling tower system feeding the water cooled condenser. Thus the 184 psig high side.

[markettech]

It's a closed loop cooling tower system feeding the water cooled condenser. Thus the 184 psig high side.

How would one deduct that it was a cooling tower based on that?

Do air cooled condensing units not also run at 184 psig?........Or am I missing something here?

Cretan, I think that was a good question....keep askin' and keep learnin'

[coolerfixer]

How would one deduct that it was a cooling tower based on that?

Do air cooled condensing units not also run at 184 psig?........Or am I missing something here?

Cretan, I think that was a good question....keep askin' and keep learnin'

Sorry, no malice intended, just a really tired brain. Anyway, pulled out the refrigerant (whatever it is) and in the process, I see flocking occuring in the sightglass in my manifold. Wonderful. So it probably is 404a reacting with the oil. So I stick the vacuum pump on for 2 hours knowing that I'm not gonna get all the gas out of the goo. Recharged with fresh R22, and BINGO, 12 degrees of SH on startup. It drops down to 10 deg SH when it nears the operating temp, BUT! The txv's are still backed all the way out. So I'm still not completely satisfied. I probably have a refrigerant cocktail now. I told the customer that I plan on pulling and replacing the charge again in a week in hopes of the flocking breaking down and releasing the remaining 404a. Box pulls down to 34 degrees no problem now, although I set it to 36 to be safe, no lite beer slushies please. Customer is happy. Oh, I measured the box too. 30' long x 6' wide x 8' high. Just a couple of feet off (chuckle).