View Full Version : Lake condensor

14-05-2004, 07:12 PM
We began this afternoon with the prepartion of two AC units from which the condensors has to be cooled from a pond near the compressors which surrounds the building.

We will lay 2 circuits of 1/2 copper on the bottom of the pond.

Our client insisted that he didn't wanted to see a condensing unit outside his new offices. We need to install it in the whole of a concrete joist.
That was our proposal for his rather strange question that won it form 3 other competitors.

When we install the unit, I will make some pictures of the location.

Indoor units will be 2 floor standing Mitsu's.

The unit is not finished yet: we need to clean it up a little bit and wire it.

14-05-2004, 08:12 PM
hi peter,

nice work!

if you add agitator to the pond you will increase heat transfer :D


14-05-2004, 08:19 PM
We were thinking more on crocodiles, preventing someone will pinch our tubes.

In the cooling water of the cooling towers (the water that surrounds it) of an electricty plant in Belgium, they cultivate salmon.

I don't have an idea of the amount of water but it's +/- 30 x 5 m and 0.7 m deep.

14-05-2004, 08:28 PM
in a month work, you might have there cooked salmons ;)


16-05-2004, 09:12 PM
Hi Peter

How are you controlling head pressure? Are you taking out the electronic control of the Mitsi? what about the EEV?

16-05-2004, 09:30 PM
We will and can’t use the standard outdoor Mitsubishi units. Owner has some peculiar demands, has the money to pay it, so why not offer a not common solution.

We will only use the indoor units. Because the expansion is in the outdoor unit, the indoor units are just simple evaporators.
We will connect a TEV on it. You can see on the pictures the liquid receiver.

Head pressure is maintained to a constant pressure via the Danfoss CPR and the NRD. Purpose is to fill up the condenser coil with liquid so that effective condensing is adapted to the temperature of the water.
If I don’t do it this way, I think we will have troubles during winter when the water becomes very cold. Because the plant is new, client has no experience if the pond freezes during the winter.

Compressors are French Unithé Hemétique’s, AC range (= no service valves on the compressors)

I will make some pictures the moment we bend the condensers and install in the lake. I will also make some pictures why we have to make a condensing unit this way. The space we have to fit it in is very narrow.

I like this kind of jobs. They asked 4 companies for an offer and we were the only who made an offer. The other 3 wanted to install only a standard outdoor unit.


17-05-2004, 08:04 PM
Sounds interesting and I look forward to the pictures :)


18-05-2004, 06:04 AM
I like this kind of jobs. They asked 4 comapnies for an offer and we were the only who made an offer. The other 3 wanted to install only a standard outdoor unit.


Sounds like fun. I just hope they don't mind the steam rising from the lake every morning!

In this country, people who have the guts to go out into unexplored territory are called pioneers. You know what they say about pioneers, don't you? They're easy to recognize because they're the people with the arrows sticking out of them!

Good luck!


25-05-2004, 07:32 PM
Installed last week the unit, Friday bended the condenser.
We bended it on the floor besides the pond and layed the stainless steel spacers on a piece of PU so that it could float.

Pond is 80 m or +/- 250 ft long and 20 m width or 60 ft and a depth of the water of +/- 70 cm or 3 ft.

You can see that the water is filled quit high. So we then pushed the PU carefully in the lake on this floats toward the final place. There we removed one PU board then the second so that it gradually sunk to the bottom.

Started up today and we were able to condens at less the 10 bar for a water temperature of +/- 15°C (so a DT of +/- 10 K)
We then raised the condensing pressure to 13 bar.
Evaporating was a little bit lower then predicted: -5°C where we had expected +3°C.

Everything is working fine.

1 + 2 coil bended on the floor laying on PU strips.
Picture 3: view of the stud welded bolts
4: view of the underground garage.

25-05-2004, 07:33 PM
Some more pictures
1. Stud welded bolt with the SS spacers, the same we use for the plate cooling of counters. The shape is exactly made for a 1/2 Cu pipe.
2 + 3 view of the narrow space we fitted it in.

25-05-2004, 07:40 PM
These are the others
Picture one taken from above. You can see the tubes going in the water. We taped the tubes.
n°2 is Pascal who's adjusting the CPC
n°3 View of the pond and the offices of the factory

25-05-2004, 08:14 PM
an adventurous man.

I like it.

chemi ;)