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Fridge

Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 350
Forum Description: 350 Hints and Tips
URL: https://www.myhanse.com/forum_posts.asp?TID=13421
Printed Date: 28 March 2024 at 16:37
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com


Topic: Fridge
Posted By: 350Bob
Subject: Fridge
Date Posted: 05 June 2022 at 12:44
Hi, we have what I believe is the original refrigeration equipment installed in our 350, an Isotherm BD35F compressor with a flat 250mm x 350mm evaporator plate mounted with the longer side vertically. We have recently been told that this evaporator plate is designed be mounted horizontally with the inlet and outlet at the top. This sounds like it could be true as the top half of our evaporator plate never gets really cold. So I have two a few questions please:
  • Is this the standard set up on the 350 as built by Hanse? If not what is?
  • Has anybody tried fitting the 250 x 350 x110 L shaped evaporator plate?
  • Are there any other configurations that people have found to work?
Although our fridge works it really struggles when the air temperature gets above 30°C and the plate ices up really quickly.

Many thanks

Bob


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H350 #205



Replies:
Posted By: JUTTER
Date Posted: 06 June 2022 at 19:09
Hi Bob,

I join a picture of the Isotherm label on my H350 (2010). Not sure it is exactly the same model of compressor you mentioned.
The evaporator plate (250x350) is mounted the same way as yours: the longer side set vertically. And it does get really cold at the top.

Claude



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JUTTER, Hanse 350#0256, 2010, deep keel, Zeeland


Posted By: 350Bob
Date Posted: 08 June 2022 at 19:05
Hi Claude,

Thanks for that information, it looks my installation is original so I maybe have something else wrong with it.

Best wishes

Bob


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H350 #205


Posted By: coriolis2
Date Posted: 21 March 2023 at 07:54
The fridge struggles because there is NO insulation around the fridge. I installed 2 sheets of Rockwool and spent 2 cans of PUR. makes a real difference in power usage over the day.



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"Coriolis" H350 #045 (ex Waarschip 570 #? 1987/1992, ex Waarschip 28LD #7 1994/2007)


Posted By: 350Bob
Date Posted: 21 March 2023 at 09:42
Thanks for your reply, can I ask where you used the insulation sheet and where you injected the polyurethane foam please? I am cautious about using the expanding foam as I have used too much on other projects and forced things apart.

Bob


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H350 #205


Posted By: martijnvdh
Date Posted: 21 March 2023 at 12:14
I will be doing a test soon with Instapak "sealed air" packaging bags for insulation of the fridge on our 371. I tried with self-adhesive 19mm armaflex sheets, but even after cutting an access hole in the backrest of the couch, I can't get enough access behind the fridge to get it glued in.

https://www.youtube.com/watch?v=PnKBIGv0CqU" rel="nofollow - Instapak Quick RT Expanding Foam Packaging - YouTube

Normal PU foam absorbs water over time unless sealed in some way. The test I intend to do is to join two sheets of 18mm multiplex together with a 5cm gap in between and see what happens with one of these instapak bags in between. Will share some info and pictures.


Posted By: Ian Coverdale
Date Posted: 21 March 2023 at 15:15
... also check there is good ventilation around the compressor unit. Hanse mounted ours in poorly ventilated box. They also installed a length of flexible hose but did not connect it. Compressor is a heat pump; extracts heat from the coolbox but must then be able to dump that heat somewhere.



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Ian & Andrea
SV Gabrielle (H445)
Liveaboards - currently Gosport UK for winter 2023/24.
www.facebook.com/sailinggabrielle


Posted By: Ian Coverdale
Date Posted: 21 March 2023 at 15:31
System is an Isotherm Compact Classic.  Only reference in installation manual referring to orientation is below. Cannot see anything to say pipe must be at top or bottom

2.11 Locating and Installing the Evaporator

The evaporator can be mounted horizontally or ver- tically on a sidewall near the top of the box, acces- sible from the box opening. In positioning the evaporator consider the routing of the refrigerant lines out of the box.

Mark the location of the mounting holes, drill and attach the evaporator with the screws and the plas- tic standoff spacers provided. Do not use screws longer than those provided, as they will penetrate the insulation (fig. 6).



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Ian & Andrea
SV Gabrielle (H445)
Liveaboards - currently Gosport UK for winter 2023/24.
www.facebook.com/sailinggabrielle


Posted By: perry
Date Posted: 22 March 2023 at 08:38
Anyone interested in improving fridge operation;
Last year I fitted a cheap electronic thermostat and internal small fan to circulate air over the evaporator plate. The improvement in efficiecy are remarkable, reduced battery drain and accurate temperature, and fast pull down to temp. The original mecanical thermostats really dont work well, the electronic unit is programmable so you can ease the load on compressor startup. And coupled with the simple cheap 12v fan from PC. Easy mod and well worth the effort.
You find my posts and picutures  at the end of this  "Fridge running strangely" thread.
Perry

https://www.myhanse.com/fridge-running-strangely_topic13565_page1.html?KW=fridge" rel="nofollow - https://www.myhanse.com/fridge-running-strangely_topic13565_page1.html?KW=fridge




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Current Yacht Hanse 315 2007
Last Yacht Hanse 301 Round GB in 2017


Posted By: Martin&Rene
Date Posted: 23 March 2023 at 15:52

Judging from some of the other positive comments whilst the fact is that not all the evaporator plate on you yacht is is cools. it is a possibility that the system needs re-gassing.

Looking at the broader picture of how to improve the performance of the fridge, there have been a number of articles on insulating fridges, so here are some links. 

This one describes the top-level job using expanding foam and has some other useful comments.

https://www.myhanse.com/reduce-compressor-running-time-with-up-to-50_topic5008_page4.html?KW=fridge" rel="nofollow - https://www.myhanse.com/reduce-compressor-running-time-with-up-to-50_topic5008_page4.html?KW=fridge


This one uses sleeping mat polystyrene foam

https://www.myhanse.com/topic12058_post99004.html#99004" rel="nofollow - https://www.myhanse.com/topic12058_post99004.html#99004

 

I just glued in pieces of 25mm closed cell foam that the building trade used.  Also remember to put pipe insulating on the pipe from the compressor to the fridge.

 

I also used the same PIR foam underneath the bed bases, as seen in an article I wrote.

https://www.myhanse.com/minimising-condensation_topic12658_post104059.html?KW=insulation#104059

 

This link shows how I improved the air flow over the compressor cooling coils with a PC fan

https://www.myhanse.com/fridge-comprressor-cooling&KW=isotherm_topic7850_post61459.html#61459" rel="nofollow - https://www.myhanse.com/fridge-comprressor-cooling&KW=isotherm_topic7850_post61459.html#61459

   

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Martin&Rene Hanse 341 Dipper Wheel steering, 3 cabin layout, normally based in Scotland


Posted By: perry
Date Posted: 23 March 2023 at 21:02
I agree with all you say.
On my 301 I installed new isotherm fridge converting from cool box. And spent lots of effort adding more insulation. On my H315 [2007] the insulation is just about OK but adding extra insulation looks like a bigg problem. However when the original thermostat failed [typical aneroid capsule type found in domestic fridge] I was confornted with a crazy price from Isotherm to replace like with like. I have replaced similar capsule thermostats on domestic fridges, and aware the same product was available at much cheaper price on domestic market.
However with fridge controls it is essensial to allow sufficient time between cycles to allow that the compressor only starts on gas [hysterisis in the crude mechanical thermostats] .
The cheap electronic thermostat shown in my photo controling my fridge is programable and you set start delay and gap max and min temps [hyterisis].  Adding to this the circulation of air over the evaporator plate [common in good domestic fridges] really makes it work well. The thermostat sensor is clamped to the evaporator plate.
I use a cheap [Lidle] internal/external digital thermometer to monitor the load in fridge, and cabin temp near fridge.
During last summer cruise in the heat of west country summer we where able to forget completely about battery discharge, with and fridge staying at 2-5 deg C. something that the setup on the 301 never achieved with similar battery capacity. It is worth saying that this setup is equally capable of running at lower temperatures if I set at -5 degc, it quicly moves on down to that set point. But 2-5 C keeps our food fresh and is as good as home fridge.
Perry
East Cowes


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Current Yacht Hanse 315 2007
Last Yacht Hanse 301 Round GB in 2017


Posted By: coriolis2
Date Posted: 25 March 2023 at 08:45
Hi Bob, will make some pictures.

Regards, Rob


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"Coriolis" H350 #045 (ex Waarschip 570 #? 1987/1992, ex Waarschip 28LD #7 1994/2007)


Posted By: Ian Coverdale
Date Posted: 26 March 2023 at 02:53
Forgive me if I've posted this somewhere here before.

Started on same path others here including the electronic thermostat module similar to that used by Perry ... and then became SLIGHTLY obsessive.

We liveaboard, travel in less populated areas, anchor often and like to keep a months supply of food aboard. Our 445's three fridges (standard galley Isotherm, optional Waeco DC30 'drinks' fridge and Dometic CFX65W fridge/freezer) gobble a very high amount of energy. Together they average ~2.1A with Dometic in 3-5C fridge mode and ~3.7A DC with Dometic in -18C freezer mode ... consumption that is there 24/7.

To monitor performance, be alerted to problems and help manage power sources, I embedded a small micro-controller in each fridge which measures temperature, power consumption and controls the compressors (not yet the Dometic). This data is sent over WiFI to our Victron Cerbo which collates the data. Eventually I'd like all code to run on Cerbo but in order to develop this and ensure the Cerbo is not overwhelmed with additional tasks, the majority of code runs on a RPI visible via laptop, iPad or mobile phone. Any 'out of norm' temperatures or power reading are highlighted in yellow and announced by a very softly spoken English female voice.

Next phase is to turn fridges into an energy store. When batteries are 100% and wind/solar is still generating, the setpoints can be reduced by 2C to absorb otherwise wasted energy and when batteries are low, set points can be raised to reduce energy consumption. 

All a bit obsessive and nerdy ... but when your domestic frdige/freezer at home has economy features and be monitored over the internet then why not the fridgr/freezers on your boat?

Cheers.





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Ian & Andrea
SV Gabrielle (H445)
Liveaboards - currently Gosport UK for winter 2023/24.
www.facebook.com/sailinggabrielle


Posted By: perry
Date Posted: 26 March 2023 at 09:24
Hey Paul nicely done,  doesnt matter if some think nerdy.
Have you  added a fan to accelerate air over the fridge cooling plate?
 I dont have your data monitoring, but my consumption and pull down times improved a lot.
I used a standard small [about 2.5"] PC fan with dropper resistor to run at about 6 volts,it was a bit noisy at 12 V, and probably moved too much air.
I think it pulled <75 milliamps total.
Perry


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Current Yacht Hanse 315 2007
Last Yacht Hanse 301 Round GB in 2017


Posted By: Ian Coverdale
Date Posted: 26 March 2023 at 10:46
Yes, the fridge volume is too large/obstructed to rely on natural convection. 

Used a 50 x 15mm blower type fan; ball bearings and brushless (£6). Experimented with location, initially close to cool plate, now mounted horizontal on the roof bit behind side door in back far left corner with short length of conduit to extend airflow into right-hand side of the fridge which creates more uniform flow/temperature. Drilled hole vertically to under the sink for wire. The whole lot is out-of-sight unless you kneel down to look for it. 

Running fan at 12V was noisy and unnecessary; now driven with WPM so speed ramps up/down to maintain 4C. Initially used STC-3008 dual electronic thermostat (£12) for compressor/fan which together transformed this fridge. Didn't stop cool-plate icing any less however!


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Ian & Andrea
SV Gabrielle (H445)
Liveaboards - currently Gosport UK for winter 2023/24.
www.facebook.com/sailinggabrielle


Posted By: spam
Date Posted: 27 March 2023 at 02:04
Nice work.  I have myself also become a bit obsessed with the power draw from my fridge.  What are you using to read the current?   I am using the Ruuvitag bluetooth wireless to read the temperature in the fridge.  That works really well.  Have been wondering about way to monitor the current for a while.  Curious how you went about it

Harold
S/V Ventus
H415/314


Posted By: Ratbasher
Date Posted: 28 March 2023 at 16:55
As a baseline for a relatively unmodified system, my power audits show that the compressor runs for 3 minutes in every 20 in summer temps of 20-28C.  My (calibrated) Victron battery monitor shows it draws between 4.5 - 5.5A in those minutes when running.  Assuming an average then of 5A, running for 3.6 hours in a 24 hour period this gives a total draw of 18A/day.  Its actually less than that as I turn the fridge off at night when not on shore power (~12A).

Lacking both the skill and the bravery to hack at the cabinets, the only modifications are holes in the exterior door of the adjacent cabinet and in the board separating it from the compressor in the hope of increasing ventilation.  Other than that we keep the fridge filled, stack it with ice when able and try to use just the top opening.

All the modifications in the posts above deserve respect and I'm in awe of those who can make changes with such professional results.  However, 350A of solar, a Balmar alternator and decent regulator produce more than enough power for our needs so I haven't yet felt the need to risk my safety in attacking an area that my wife makes very clear is her personal domain.

I do like Ian's idea of a separate beer-fridge though....


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H400 (2008) 'Wight Leopard', Gosport UK


Posted By: coriolis2
Date Posted: 28 April 2023 at 12:53
Hi Bob, as promissed but a little late the pictures:

I applied about 1.5m2 of rockwool trough the underside and the hole on the left side of the oven. Furthermore a can of PUR via holes as pictured below. It can keep up high ambient temps now without high Amps and without any condensation.

Overview:

Hole pattern on the cabin side:


Hole pattern on the inside (1/2):


Hole pattern on the inside (2/2):


Access left of oven with oscillating multi tool:


Best regards, Rob


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"Coriolis" H350 #045 (ex Waarschip 570 #? 1987/1992, ex Waarschip 28LD #7 1994/2007)


Posted By: 350Bob
Date Posted: 30 April 2023 at 17:17
Hi Rob,

That is really useful information, thanks very much for the detailed reply.

Best wishes

Bob


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H350 #205



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