Condenser air re-circulation

[not2sure]

I’m having problems with condenser discharge air re-circulation back through the condenser on three air-cooled 400-ton chillers. The chillers are placed on the west side of the building, spaced 6 feet from the building (30 ft tall) and 10 feet between the chillers. We also have a prevailing wind from the South West. On a 90 deg day temperatures between the chillers can reach 125 deg. I’m looking for suggestions.

[The Viking]

Depends on what condensor fans you got.

If they are powerful enough, then you might be able to put duct above each fan, creating a chimney. That should reduce your problem.

[Frostycold]

More information is required here. By my calculation you have 1,200 TR cooling or in metric that is roughly 4,200 KW. That is some cooling capacity. Re-circulation of air off the condenser will seriously affect this cooling capacity. Is all the cooling required or can one chiller be switched off or otherwise rotated. To offer a practical solution much more information is required.

Regards Frostycold

[US Iceman]

On a 90 deg day temperatures between the chillers can reach 125 deg.


Call the architect and ask him to move them at his cost. He is probably the one who specified the units be placed there.

They always try to hide these behind walls or some other remote place and the result is almost always the same.

Try this link for some additional information:
http://www.evapco.com/media/pdf/311H-Equipment-Layout.pdf

See page 3 & 4 for general concepts. Once the equipment is installed it's difficult to fix.:(

[Lowrider]

We had an install a few months ago where the architect specified that the condensors would not stick out above the walls.

The condensors were only 20cm from the roof and inclosed at either side by the wall 50cm away and a duct at the other side, some 60 cm away!

We had the pipes and brazing done by someone else who thought he knew better and installed 16bar pressure relief valves in the dischargeline since he did the instal and told us the copper lines and our machine wasn't able to cope with more than that!

After all the brazing he pressuretested the system, vacumed it and filled all 4 circuits (2 machines) with R134a.
The oil, which comes with the unit in a can, was still in the can. We had to pump it in afterwards on commissioning.

On inspection of the system I found 2 leaks.

After much debate we moved the condensors up and fitted the right relieve valves. (Gave the architect the choise, either we move it up or the unit goes offline!!)

[US Iceman]

Who paid for the all of the changes you made?

[Lowrider]

the owner, getronics pink roccade, now KPN!

[US Iceman]

This is something that happens all of the time. The owner paid for this once, why should he have to pay the second time since the architect usually locates the units?

[Samarjit Sen]

This happens all the time. The architect without knowing the pros and cons of the location of the Air Conditioning or Refrigeration System will try to locate these units in an obscure place. It is always the owners have to pay extra. The architects should consult the refrigeration firm and design his building accordingly. I always make it point to tell my client that before any designing is done by the architect, I would like to meet him and discuss the locations.

That way everybody is happy.