Refregeration art

Big Will

The artist made the first one in the seventies. It was destroyed years ago. This one was commissioned by the owner of an art gallery in Zurich. the intention is to frost the letters. I have a 134A condenser with cap tubing going to each line of letters. The tube size is JB ind. #2 @ 105". The problem is anything over 72 deg ambient it wont freeze. I think I have enough capacity but really how can you size something like this. This morning with a 66 deg. ambient temp I had an evaporator temperature of 20 deg and it worked great. this afternoon no ice just condensate. The condenser is a 1/3 hp. Any thoughts. I may just buy a larger condenser on Monday.  

Empire_2

Interesting...

Neat project to say the least.  As far as capacity, each line of letters will have a set load depending on how many letters and it's length.  Your cap tubes must be able to handle each line or it's load (cap must be proper size and length).  The suction line is actually not a true measure of the evap temp, but a sum of all lines together.  Unless you measure each line of letters after it ends and dumps into the common suction line.  Have you thought about serving your lines with 1 cap tube installed before it gets to the whole area?  This would insure that the entire load be treated as 1 coil (load).  At least now the suction line temps would represent the entire project.  You need to research the heat transfer of copper tubing and then you can total it up and determine the total capacity needed.  This is just my opinion and others input will help.



Mike T.

Techman

Art

Getting a set of readings would help narrow down if the cap tubes are sized properly or if the compressor is undersized.And what is the mfrg and MN# of the comp/cond unit.You might have a "medium temp " cond unit when a" freezer " cond unit might be better suited.And what TXV is in there? I can't see, is there a Moisture Indicator  and a Filter Drier in there somewhere? There are 4 -  105" of cap tube in parralel ?

Big Will

Thanks for the intrest

I did a bit of research though limited. IT is a high temp Tecumseh condenser. With my ideal 20 deg evaporator it has a capacity of 2,340 BTU. Its mothers day so I have been unable to  measure but I am guessing I have a total of 35 to 50 feet of 1/4 inch tube in four each row. I would love to maintain 20 deg evaporator tube temp @ 80 deg ambient. The gallery is in Zurich were the summer is not horribly hot. The gallery is in a concrete building that does not get warmer than 72 deg. However this is according to the owner and I would rather design for 80deg and be a bit over capacity. 

Techman

Big Will

WE still need a set of pressure/temp readings  ,room temp, superheat readings,and others in order to help figure this out.With these readings we can determine if the system is operating at or near that 20* evap temp you want. Is the TXV thermal bulb insulated? Sight glass/moisture indicator? Filter drier? What keeps the heat of rejection from the cond unit from re-entering the piece of art? How did you determine the BTU load? I maybe looking at the wrong JB cap tube chart ,because my chart shows #'s like TC-26,TC-31 ,TC-64. Possibly Bullet Restricto cap chart?

Big Will

Brand spacific

each brand has different names for their tube sizes. They do have conversion charts. I will have more info this afternoon. Look at the pic though. He placed the condenser directly below the art on its stand. The phrase is the evaporator and the base for the piece holds the phrase and the condenser.  Also if I have cap tube so no TXV.

Techman

Big Will

What is that device/thing to the left of the cond unit? Is that a reciever tank inbetween the cond coil and the comp? Can you direct the hot discharge air away from the cond unit so as to not put a false load on the  evap coil of therefrig system? And running press/temp ?