Author Topic: Fridge running too much  (Read 12220 times)

Odysseus

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Fridge running too much
« on: December 29 2011, 10:13 »
I spent a lot of time looking into this and have spoken to a number of engineers including the Bavaria agents in Hamble, none came up with a simple fix, most wanted to change the unit for a "new up to date one"

When talking to the "Penguin" engineer after I had fixed it he told me he always does that.

First
The heat from the exchanger goes up through holes under the fridge and heats up the bottom of the fridge.

The fan cooling the heatexchanger uses the air that is hot

The heatexchanger gets clogged with fluf

The fix

Cover the holes under the fridge and block off the back.

Clean out the heatexchanger

And the most important, reverse the fan on the heatexchanger so it pulls air off the cabin floor.

I also put another fan in to pull out hot air.

Now runs for 12m and off for up to 55m. remember I am in France and it get hot.

Odysseus
Odysseus

Nigel

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Re: Fridge running too much
« Reply #1 on: December 30 2011, 16:56 »
I spent a lot of time looking into this and have spoken to a number of engineers including the Bavaria agents in Hamble, none came up with a simple fix, most wanted to change the unit for a "new up to date one"

I've had good results by adding loads of insulation in the bottom cabinet, keeping that warm air away from the cool part.

Another tip is that if your Danfoss compressor is running your batteries down too low, you can fix it with a single resistor. Download the instructions for the Electronic Unit for BD35/50F Compressors, and fit the resistor shown between C and P [item (9) in the diagram], following the table below for the cut-out voltage you want. I've got the maximum 82k ohms, giving the highest cut-out of 11.3V.
Nigel Mercier: Forum Administrator

CRYSTAL

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Re: Fridge running too much
« Reply #2 on: January 05 2012, 20:59 »
1) Has anyone encountered issues with leaks and if so, was it at the couplings or the somewhere else. Any leak detectors out there? I'm thinking of getting rid of the quick connect couplings. Don't think these couplings work great from all the vibration that's produced in the marine environment....

2) Anyone tried increasing the Compressor speed by adding the a resistor as pointed in item 8 between the thermostat and C  - 
http://www.ra.danfoss.com/TechnicalInfo/Literature/Manuals/06/BD35-50F_101N0210-20-40_0300-20_08-2011_dehcei100b602.pdf

R,
Hratch
Hratch
CRYSTAL I

Sweet As

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Re: Fridge running too much
« Reply #3 on: January 08 2012, 03:57 »
Thanks for the ideas regarding improving the fridge efficiency. A couple of follow up queries;

The fan on my heat exchanger is drawing air through the fins. The fridge compressor and heat exchanger unit is mounted aft in the locker under the port settee. I intend to purchase another fan and mount it near the fwd top of the locker drawing air out into the cabin. Does the whole unit become significantly noisier with this addition?

What is a good insulation material to pack around the bottom of the fridge vessel? The is not much room to feed material through into this cavity.

Thanks
Sweet As
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Odysseus

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Re: Fridge running too much
« Reply #4 on: January 08 2012, 10:35 »
The fan on the compressor originally draws the air through the heat exchanger but the air it is drawing is hot from the compressor that is in the immediate vicinity, so turning the fan around and putting an extra computer fan in to draw out hot air turns the flow into a circular motion. There is a marginal increase in noise as you would expect but the improvement far exceeds the noise issue. I have put a baffle plate on to tide the exit up.

The insulation needs to be flexible as you say getting into the area and around the pipes is not easy so I used a hot water cylinder jacket cut in half and the other half was put around the calorifier hot water tank.

I have also thought about putting spray foam under and around the fridge compartment but have not done as yet as the efficiency is acceptable.

Hope this helps
Odysseus
Odysseus

Monique

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Re: Fridge running too much
« Reply #5 on: January 26 2012, 06:27 »
Now curing the problem permanently. 

New Frigoboat + keel cooler. Beer shall be cold  :D

Odysseus

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Re: Fridge running too much
« Reply #6 on: January 26 2012, 09:42 »
Tried running your Frigoboat + keel cooler with the boat lifted out!!! Mine still works.

Odysseus
Odysseus