low temperature refrigeration piping layout

[coldseeker2012]

Good evening to everyone.
Most of the time I see in low temperature walk-in freezers both the suction and liquid lines connected to the evaporators and then going immediately up through the ceiling panel, and then towards the condensing unit. Is it possible to go with the same piping across the walk-in and then through the wall panels instead of the ceiling? I don`t know if the freezing temperatures (-20C) may have some effect on the pipe insulation and/or the liquid refrigerant going thru the liquid line. Thank you.

[Rob White]

Good evening to everyone.
Most of the time I see in low temperature walk-in freezers both the suction and liquid lines connected to the evaporators and then going immediately up through the ceiling panel, and then towards the condensing unit. Is it possible to go with the same piping across the walk-in and then through the wall panels instead of the ceiling? I don`t know if the freezing temperatures (-20C) may have some effect on the pipe insulation and/or the liquid refrigerant going thru the liquid line. Thank you.


The pipes need to be as direct as possible and as neat as possible.
Running the pipes inside the room may effect the temperatures of
the refrigerant which may have an effect on the efficiency of the system.

The cooler the liquid is, the higher the sub-cooling and this might actually
improve efficiency but it would need to be designed correctly before installed.

Regards

Rob

.

[coldseeker2012]

Thank you for your response. I also thought about a possible subcooling of the liquid refrigerant going through the piping in a freezing ambient. But I guessed it might be good for the system. My biggest concern is the possibility of condensation on the suction line insulation due to high levels of humidity/temperature in the attic above the walk-in freezer, in case the pipes must go through it. If I can run the pipes across the walk-in, I wont have to worry about this.

[al]

The insulation will break down over time, you may need to use preinsulated pipe with a plastic coating.

al

[Rob White]

.

I have seen pipes run on the inside of cold-rooms and as long
as basic precautions are taken then it can always be done successfully.

The pipes could be protected with a top hat metal covering and as for when
they come back out of the cold room just make sure normal good quality insulation
is used and all vapor barrier precautions are used then there will be no sweating or condensation.

Regards

Rob

.

[THE DUDE]

I usualy run the line up through the cieling. I do it because the customer usualy has shelving tight to the walls.

[coldseeker2012]

One more thought about installing the piping through the inside of the walk-in: piping supports and hangers most likely would have bolts going all the way through the walls or ceiling, which brings the possibility of condensation once these bolts get to the outside. Do you know of any design or type of support that would minimize this problem?

[al]

Sleeve the threaded rod with plastic tubing, foam the hole, use armaflex to insulate the threaded rod where it exits the room.

al

[Rob White]

.

Use plastic rod.

They are more than capeable of holding a pipe tray,
They hold evaps to the ceiling with them.

But The weight would not be that great and I imagine
you could use fasteners to bolt the pipes the the inside skin.


Rob

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[Coorsman777]

Use as little pipe in the freezer as possible. Less chance for customer to damage the piping and insulation.