Fitting fan to Thetford fridge

[DavidCh]

Full of good intention I decided to fit a fan to my Thetford fridge. I originally looked at the Thetford unit but it was not practical to fit as the upper vent is higher than the top of the fridge so there is no easy access to the back of the fridge without removing it, which seemed like far to much hard work. I therefore purchased a CBE MCV-2 unit with the idea I could just fit that in the upper vent, bolt on the fan, pick up power from the fridge connections on the bottom of the fridge, drill a single small hole for the control panel and then seal that up with silicon, simples! I intended to put the control panel in the cabin right next to the fridge where I can drill through to the back of the fridge,

https://www.cbe.it/mcv-2/

So, I now have the unit and it is not as I imagined. There is a pre made connector that plugs into the control unit that would need about a 2cm hole to get through. The control panel is not flush fitting and needs about a 5cm hole to fit and the control panel itself is certainly not airtight. The control panel has no enclosure so its just electronics hanging off the back and going into the hole. DC power goes to the control panel first. Everything I read tells me that I must maintain airtight integrity between the cabin and the back of the fridge because of carbon monoxide and I cant see how to achieve that. because the control panel itself is not airtight. I am also not enthusiastic about drilling a 5cm hole to the back of the fridge in any case!

As I see it my only option is to fit the control panel behind the vent in the back of the fridge which means opening the vent to switch it on/off/auto and adjust the temperature.

Am I missing something very obvious?

 

[JustifiedAncient]

Hi David, how did you get on with this in the end?
I believe CBE do a surface mount box and/or a spacer that would allow the module to screw to a wall needing only an 18mm hole to pass the connector/cable through. But you are right, most people will be mounting this through the wall from the fridge enclosure so resealing the cable entry is important - something not mentioned in the CBE instructions.

 

[Howard B]

I took a ply panel out adjacent to the fridge which house a USB/ 240v socket and mounted the controller in the panel. I am sure my kit came with a spacer, but it wasnt needed.

 

[Reallyretired]

My thermostatic switch is just at the bottom of the fridge behind the lower grill.
There is no need to frequently access it, just turn it on before going away in the summer and turn it off when I get back, just leave it off in the winter.. The fans use no power when they're off, and come on when the temperature at the back of the fridge reaches 30C and off when it drops to 28C. (on all day in this weather) No need to ever adjust the settings once its set up to your requirements.
Mine just uses two 5" computer fans at around £5 and a thermostatic controller with remote probe from ebay, again about £5

 

[DavidCh]

At the moment I have ‘bottled out’ and it’s still in the box. I think the way I will go is to mount it in the fridge compartment and access it by removing the lower vent when I need it. It’s not a very good solution though. I do feel that CBE have not thought this through, which is a great shame

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[DavidCh]

This prompted me to read the manual again, I guess I could put the control panel behind the lower vent, but have an on/off switch in the van?

 

[Richard n Ann]

I'd drill the bigger hole out, you should see the size of the hole I had to cut for the BM1 monitor but it's flusher and looks nice now

 

[DavidCh]

I'd drill the bigger hole out, you should see the size of the hole I had to cut for the BM1 monitor but it's flusher and looks nice now

My concern is not cutting the hole, it’s the carbon monoxide from the back of the fridge getting into the living area

 

[Howard B]

How confident are you that the fit of of the fridge is airtight? Would a CO monitor not pick up any leak into the cabin.

 

[MichaelT]

My concern is not cutting the hole, it’s the carbon monoxide from the back of the fridge getting into the living area

Our dometic fridge has a gap at the top between the 2 pieces of aluminium where I ran the wires through, discovered it blows a gale thru there in winter so would not worry about carbon monoxide, however I have now taped it up with heat resistant tape to stop the draugh.

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[Lenny HB]

At the moment I have ‘bottled out’ and it’s still in the box. I think the way I will go is to mount it in the fridge compartment and access it by removing the lower vent when I need it. It’s not a very good solution though. I do feel that CBE have not thought this through, which is a great shame

Just remove the pins from the plug you are supposed to use a special tool but a jewellers screwdriver normally works just need to push the tab down & pull the pin out. Then you can put the cable through a small hole & reconnect.

Or cut the wires pass through the hole and solder back together.

If you mount it in the back of the fridge you will need to give the board a couple of coats of tropicalizing varnish or mount in a watertight enclosure or it will corrode and not last long.

 

[Richard n Ann]

Our fridge back was never air tight anyway. Even after I stuck armaflex tape round it there was a draught coming in above the fridge and cooker when it was windy. Just fit a Co detector and don't worry about it.

 

[DavidCh]

Just remove the pins from the plug you are supposed to use a special tool but a jewellers screwdriver normally works just need to push the tab down & pull the pin out. Then you can put the cable through a small hole & reconnect.

Or cut the wires pass through the hole and solder back together.

If you mount it in the back of the fridge you will need to give the board a couple of coats of tropicalizing varnish or mount in a watertight enclosure or it will corrode and not last long.

I love this forum. Of course I knew that, just it was deeply buried in my brain and never quite got the the top!

Of course, its obvious. Occum's Razor

D

 

[JohnH17]

All I can say is what I'd do - and I'd do exactly what you're suggesting! Lash it up, controller in the bottom behind the vent, and see if it works, and works how you want it to. If it does, and if it's irritating having to take the bottom panel off, then I'd go for stage 2 - I'd cut a hole big enough for the pcb so the controller front fits flush, then at the back, use the lid off a small die-cast box (like https://cpc.farnell.com/camdenboss/5100-124/diecast-box-natural-111x60x31mm or smaller), after filing a slot on one edge for the wires to pass through. Smooth off so no sharp edges. Seal the slot with non-setting heat-proof gunge and screw down the lid with the four holes provided. I'd use die-cast rather than plastic just in case it gets hot before the fans cut in. But the idea depends on your layout - maybe it's not practical in your van; and I wouldn't drill anything visible at all until I knew I wasn't going to change my mind! Good luck with it anyway!

 

[Stealaway]

This prompted me to read the manual again, I guess I could put the control panel behind the lower vent, but have an on/off switch in the van?


I bought two computer fans from eBay and and fixed them to those rails.
There is plenty of room to fit them behind the top grill. They are screwed up to the top of the void and are set to blow so they will pull air over the radiator from the bottom grill. I took the supply wires trough an existing sealed hole un the rear void and picked up a 12V feed from a USB socket in the bedroom
I have pushed the temperature sensor in to fins at about middle.
It was actually too powerful so I disconnected one fan. One fan is more than in enough

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[bertiebasset]

I fitted mine a good few years ago. 2 12v computer fans £5 or so. 1 temperature controller
( https://www.ebay.co.uk/itm/36392619...d=link&campid=5338547443&toolid=20001&mkevt=1) and a 12v switch. Fans in the top fridge vent.(tall fridge/freezer), controller at the side, power from below connections via a switch in the hab doorway. Switch is lit so I remember to turn it off. Temp set to come on at 35 and off at 30.c. and can be seen from ground through upper vent cover.
Works a treat and only a VERY small hole filled with switch.