Fridge fan installation ... DIY info please (3 Viewers)

[Two on Tour]

The one thing I have found is although I can get the fridge and freeze section in the van down to normal home fridge/freezer temperatures I do find that in the fridge compartment I have quite a temperature difference between the top and the bottom of the fridge (7 degrees at the top and 4 degrees at the bottom) so my next bit of bodgery is to fit a fan in the food compartment of the fridge to circulate the air to hopefully maintain a uniform temperature from top to bottom.

 

[bjandlin]

Hello, a couple of photos of my installation,if they loaded.
Hope it gives you an idea.
Barrie.

 

[Minxy]

The one thing I have found is although I can get the fridge and freeze section in the van down to normal home fridge/freezer temperatures I do find that in the fridge compartment I have quite a temperature difference between the top and the bottom of the fridge (7 degrees at the top and 4 degrees at the bottom) so my next bit of bodgery is to fit a fan in the food compartment of the fridge to circulate the air to hopefully maintain a uniform temperature from top to bottom.

You might want to re-think that ... fridges should have different temperatures top and bottom as some food in it is 'happiest' slightly colder than other bits.

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[Two on Tour]

Food in the fridge at different levels for different temperatures, wow that not going to happen with us, we just bung it in were it fits and squeeze the rest in as best we can.

 

[Alistair33]

This is what I did with mine, links further down the thread to suppliers.
I would throw your 50p fan in the bin and buy a couple of decent fans, you need quiet ones that will shift a fair bit of air. You also need two.

How do you remove the white exterior grill, does it just pull off ?

Got it, the black clips slide to release the grill

 

[Diabalo]

On mine there is a white locking button each end that turns through 180 then pull the grill off.

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[The Wino]

If it's not too much trouble that would be good.

I'm gonna try it with the single fan I've bought already and see how it goes from there ... the fridge works fine but I want to keep it that way so am looking at a 'preventative' measure rather than a 'problem solving' one ... hopefully a single fan will be sufficient, if not I'll just get another to go alongside ... at least the bits would already be there so it would be an easy job to put on a second fan if needs be.

If it works fine I would leave it alone ours was fine last year in 35 degrees on gas! the fan when not switched on will impede airflow. I its not broken don't mend it!!!

 

[Lenny HB]

If it works fine I would leave it alone ours was fine last year in 35 degrees on gas! the fan when not switched on will impede airflow. I its not broken don't mend it!!!

Did you actually check the inside of the fridge temperatures? If you did I doubt you would be making that statement.

 

[Lenny HB]

The one thing I have found is although I can get the fridge and freeze section in the van down to normal home fridge/freezer temperatures I do find that in the fridge compartment I have quite a temperature difference between the top and the bottom of the fridge (7 degrees at the top and 4 degrees at the bottom) so my next bit of bodgery is to fit a fan in the food compartment of the fridge to circulate the air to hopefully maintain a uniform temperature from top to bottom.

Mine is the other way found far colder at the top. With the fridge empty it gets quite cold down below zero. Once you load it up temperature goes to pot without external fans running 11-12 deg at bottom 6-7 at top. With fans running 4 at top 9 at bottom in ambient of 25-31.
Once we get home I will be doing the @Robert Clark mod of internal fan.

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[jockaneezer]

Those Arctic F12 TC fans have a built in thermocouple but be aware that unless you bypass that and use a separate temperature controller, the fans run all the time they are energised, they 'tick over' at about 500 rpm, then 'ramp up' to full speed as the temperature increases.
I'm in the middle of fitting them to my Dometic fridge, unfortunately I dropped the fridge vent cover as I was trying to remove it (it was stuck to the oozed out non setting mastic on the surround) and broke two corners off it. Looks like a replacement is about £60

 

[Lenny HB]

Those Arctic F12 TC fans have a built in thermocouple but be aware that unless you bypass that and use a separate temperature controller, the fans run all the time they are energised, they 'tick over' at about 500 rpm, then 'ramp up' to full speed as the temperature increases.
I'm in the middle of fitting them to my Dometic fridge, unfortunately I dropped the fridge vent cover as I was trying to remove it (it was stuck to the oozed out non setting mastic on the surround) and broke two corners off it. Looks like a replacement is about £60

Have a look on German ebay, seen the vent complete with winter cover cheaper than just the cover in the UK.

 

[EuroTrotters]

those who dont want to do their own

www.city-cooling.co.uk

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[The Wino]

Did you actually check the inside of the fridge temperatures? If you did I doubt you would be making that statement.

Even the French cheese was fine and white wine cool enough to drink perhaps its down to the installation/direction of the sun/whatever. I didn't check the temperatures but have never done at home either and still breathing!!

 

[Two on Tour]

Here are a few photos of our setup.

We bought the van last year which is a home brew and the fridge position within the van is not ideal so I had to work around what we have.

The fans are mounted on a perspex sheet (just because I had it to hand) and that in turn is screwed to the back of the vent mounting frame.
I went for these fans as they individually push through 60 cubic foot of air a minute and draw only 0.075 of an amp each and are quite at 18dB.
Another factor for me was that the blade design offered less blocking of air flow when their not turning. I opted for 2 fans at the top to give me control options if needed.
I got a bit carried away and fitted another fan near the bottom vent as I thought that the volume of air coming into the bottom vent might want some help supplying the top fans. The bottom fan is independently switched from the tops fans but is in the thermostat circuit.

I would have used one of the little Chinese electronic thermostats but there was no sensible place to mount it or get cabling to it so I went for a capillary type manually adjustable thermostat.
I wired the fans via a 3 way switch so they are either on constantly, via the thermostat or off. I also wired in switches to the top fans so I can run either one or both.

The thermostat bulb (sensor) is mounted above the fridge cooling fins about an inch away. I then used a cheap laser type thermometer that I have to set the thermostat to fire up the fans at 30 degrees. The amount of fans and switching I installed may appear to be a bit over the top but I was worried that the greater airflow past the burner flame may have blown it out so I wanted to cover as many options to control the fridge so it operated at the optimal temperature.

 

[Lenny HB]

Even the French cheese was fine and white wine cool enough to drink perhaps its down to the installation/direction of the sun/whatever. I didn't check the temperatures but have never done at home either and still breathing!!

French cheese is supposed to be served at room temp and crawling of the plate.

My fridge is working better today, fridge side of van facing sun outside temp 25, centre of fridge maintaing around 4 deg with fans running, but its quite cool outside when it gets into the 30's inside temp will rise, have turned it up to max and it is less than half full.
Having been monerting it over the last couple of weeks performance goes to pot when it's full.
What's the point in having a nice big fridge if you can't put much in it.
Would be interesting to get some measurements of Thetford fridges to see if they are as bad as Dometic.

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[berni109]

Think u have got the gist of it from the previous posts.
On the mounting side i found that the fans i got were a nice snug fit into white electrical trunking corners and straight connectors. Just 2 corners if u want 1 fan and fixed these to the bottom of the back of the vent housing with self tappers and some super glue and a straight connector at the top without the glue.
hth

 

[Sandancers]

Does everyone mount the sensor just above the cooling fins ?

 

[Two on Tour]

Although I said my sensor was mounted above the cooling fins it is in fact not directly above but higher then the fins and slightly towards the vent.
It made sense to me to mount it there as I wanted the sensor to measure air temperature near the cooling fins rather than the temperature of the fins directly. Hopefully other will report on the position of their sensors.

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[Jenben]

Would be interesting to get some measurements of Thetford fridges to see if they are as bad as Dometic

We have a Thetford fridge and originally had lots of problems, especially when it was hot outside. After a lot of trial and error we found that rather than outside temperature the biggest impact was caused by how level the fridge was. If it's perfectly level then performance was ok even in temps up to 30°c, but if even 1-2° off level then it rapidly heated up. Apparently Dometic fridges are more tolerant, but I was surprised just how much impact it made.

 

[Two on Tour]

I can back up observations on the Thetford fridge needing to be level.
We moved house 3 years ago and our drive is now on quite a slope. Our previous motorhome was fitted with an Electrolux fridge and worked ok on the drive as we would start the fridge up and load it a few hours before we would set off. Our new to us van is fitted with a Thetford N90 fridge and worked fine when demonstrated to us when we bought it, but when I started it up and loaded it before our first adventure out in it I noticed the temperature in the fridge rising. We were at the point of no return so I thought bugger it and slung some ice packs in the fridge and hoped for the best. When we pitched up I switched back over to gas and the fridge looked to be working again and it was because we were on level ground. I ran the van up on levelling ramp when we got home and the fridge worked fine.

 

[Lenny HB]

Although I said my sensor was mounted above the cooling fins it is in fact not directly above but higher then the fins and slightly towards the vent.
It made sense to me to mount it there as I wanted the sensor to measure air temperature near the cooling fins rather than the temperature of the fins directly. Hopefully other will report on the position of their sensors.

You can see mine in the first pic here, mounted on a strip of aluminium between the fans should give a more stable reading like that. It's about 15-18 inches above the fins.

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[Lenny HB]

We have a Thetford fridge and originally had lots of problems, especially when it was hot outside. After a lot of trial and error we found that rather than outside temperature the biggest impact was caused by how level the fridge was. If it's perfectly level then performance was ok even in temps up to 30°c, but if even 1-2° off level then it rapidly heated up. Apparently Dometic fridges are more tolerant, but I was surprised just how much impact it made.

Been parked on quit big slopes and Dometic fridges have always carried on working well out side their spec. In the case of Dometic I use the word working in the loosest possible sence.

 

[Two on Tour]

You can see mine in the first pic here, mounted on a strip of aluminium between the fans should give a more stable reading like that. It's about 15-18 inches above the fins.

Yup, had seen your photos. It's alright for you guys with big tall fridges boasting about your 15 to 18 inches above but for us blokes with only little fridges we can only get a few inches above the fins.

I'm trying to measure the heat coming off the cooling fins. Because of the gap between the back of the fridge and the inner skin of the van not all the air flow from the lower vent will pass over the cooling fins, some cooler air will come in the lower vent and straight up the gap and out the top vent and I felt that this was likely to give a miss reading of the actual temperature at the cooling fins if the sensor is mounted at the vent it's self. I appreciate that you can compensate for that by adjusting the thermostat to gain the desired temperature within the fridge, so I feel that both position work because I know mine does and I'm sure yours does as well.

 

[peterc10]

When I last looked at this a couple of years ago you could buy a kit complete with everything including fans, controller etc. A couple of companies seemed to make them, one was Brunner I think. Has anybody seen them on sale in the UK? Tried a google search but found nothing.

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[Newfie]

When I last looked at this a couple of years ago you could buy a kit complete with everything including fans, controller etc. A couple of companies seemed to make them, one was Brunner I think. Has anybody seen them on sale in the UK? Tried a google search but found nothing.

 

[Lenny HB]

When I last looked at this a couple of years ago you could buy a kit complete with everything including fans, controller etc. A couple of companies seemed to make them, one was Brunner I think. Has anybody seen them on sale in the UK? Tried a google search but found nothing.

Problem with the commercial ones is they have a fixed thermostat which is far from ideal. Different fridges different installations one for all just doesn't work.
Far better to have the flexibility of an adjustable themostat , also you can achieve a neater more professional installation doing it all yourself (well I can) and much cheaper.

 

[peterc10]

Problem with the commercial ones is they have a fixed thermostat which is far from ideal. Different fridges different installations one for all just doesn't work.
Far better to have the flexibility of an adjustable themostat , also you can achieve a neater more professional installation doing it all yourself (well I can) and much cheaper.

The Brunner one has an adjustable thermostat. I know nothing about this sort of thing and would rather have one where they have done it all for you. And if it don't work I can send it back.

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[Lenny HB]

The Brunner one has an adjustable thermostat. I know nothing about this sort of thing and would rather have one where they have done it all for you. And if it don't work I can send it back.

Not seen the Brunner one all the ones I've seen had fixed thermostats and a ugly control panel you need to mount somewhere.
I just like doing things the hard way, no fun in buying something and just bolting it in.

 

[Richard n Ann]

I did mine the hard way, this is the thermostat board I made on veroboard. I've got 2 fans wired in series so they are quiet. The temperature isn't adjustable without changing resistors so I move the thermistor about in the condenser fins, works great.
Circuit diagram available if anybody is interested.

 

[peterc10]

Not seen the Brunner one all the ones I've seen had fixed thermostats and a ugly control panel you need to mount somewhere.
I just like doing things the hard way, no fun in buying something and just bolting it in.

Your point about the ugly control panel is good - the Brunner is not the prettiest, and in white it does not go with the other switches etc I have. That is the reason why I did not buy it when I was first looking.

But I do want one with a visible control panel. I have now found a CBE one that has a much better looking panel and it is also adjustable temperature, but I can only find it sold by German suppliers and it is more expensive.

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