Cooling fan installation for Thetford fridge

[wildebus]

Thing is that if the doors aren't opened the fridge doesn't switch on and thus heat isn't generated so fans make no difference. ...

I think you are being ever so slightly over-literal there. On your basis, you could remove the power to a fridge for a week if you are not taking anything out of it and it would still be cold?

I don't think so!

 

[r4dent]

I did the test whilst the van was layed up so the results weren't skewed by opening the fridge door,

Thing is that if the doors aren't opened the fridge doesn't switch on and the heat isn't generated so fans make no difference.

Next time do it on a really hot day in Spain and have a can of beer every 30 minutes.

View attachment 151530

 

[wildebus]

is there an echo in here?

 

[Pudsey Bear]

What?

 

[r4dent]

I think you are being ever so slightly over-literal there. On your basis, you could remove the power to a fridge for a week if you are not taking anything out of it and it would still be cold?

I don't think so!

Quiet correct after a week the beer would be too warm.
Although I have often used the 2 night (33 hour) crossing to Spain with no power to the fridge with no problem.

Only to pleased to amend my comment.

"Thing is that if the doors aren't opened the fridge doesn't switch on for long and thus very little heat is generated so fans make no difference. "
Fans help most when the fridge is cooling for long periods and a lot of heat needs dispersing.

 

[Canalsman]

I fitted a fan kit to my compressor fridge!

No massive reason to, but if the fridge side of the motorhome is on the sunny side, the area around the compressor CAN get very warm indeed and outside the official operating window.
TBH, my main reason was to just to install a kit and try it out (I like to test these things on my own stuff before I do it to other peoples vans )


What you could add if you had a mind to is a simple temp controller that will turn the fans on and off at certain temperatures (that you chose). These are literally just a few pounds in price, would use the existing wiring you have in place and if you replaced your switch with a 3-way switch, you could select the fans to be ON, OFF or Temp Controlled.
I can give you more info and a link if this is of interest?

Yes please David.

 

[Canalsman]

I have three fans fitted in the vent on my fridge, unlike other comments on here I found that the fridge is significantly cooler in hot weather. In the South of France/Spain in July and September my fridge was useless before I fitted the fans, with the fans I could make ice cubes and keep frozen food safely.
If there are any gaps around the fans they don't work efficiently, so the ones pictured in the OP should give an improvement but I am sure Chris will give us an update

This shows there are no gaps...

 

[MERL]

Thing is that if the doors aren't opened the fridge doesn't switch on and thus heat isn't generated so fans make no difference.

Next time do it on a really hot day in Spain and have a can of beer every 30 minutes. (or leave the door open)View attachment 151527

If I had a can of beer every 30mins I wouldn't give a toss about the fridge after a few hours anyway .
Seriously though, there's still losses through the insulation and you could clearly see the stat kicking in every so often on a regular pattern as it kept up with those losses. You could see the temp falling when the stat clicked in and then you could see the temp rising while it clicked off. The fall and rise graph seen on the temp curve was exactly the same with or without the fan running as was the length of each on and off time period. I could see no greater efficiency of cooling power with the fan running so I can't figure out why opening the door every now and then would change how 'good' the unit was at actually cooling?
I know other folks have said that fans have improved things for them but we all know that we can be subconsciously biased when it comes to this sort of thing, it takes time to fit a fan and the weather will have changed by then, also the packing of the fridge makes a massive difference to how well they operate as well as how many 'warm' items are put in and how often you open the door. "My fridge works better now I've fitted a fan" is hardly conclusive scientific evidence because soooo much other stuff may also have changed too, even the country or time of year could have changed! Surely an actual proper experiment with reasonably monitored and controlled conditions would be a far more reliable indicator? Wouldn't a greater cooling power provided by using a fan have shown up as a steeper drop in temperature on the chart and hence a shorter run time?

I wasn't in Spain but I did try it on what was two consecutive days that were a very warm for the UK, sorry but I didn't make a note of the ambient but Id say around the 30 Deg mark. Maybe the ambient simply wasn't high enough to affect my particular fridge?

So everyone, post your experiences with fridge fan effectiveness be that good, useless or indifferent but please be objective if possible.
If your fan struggled in Spain so you fitted a fan and then went away in Wales and it worked great then ......

 

[Canalsman]

The only criticism I would make is that the fans are quite noisy. They are moving a lot of air.

This makes @wildebus suggesion of a temperature controlled switch a good one.

Or fitting a speed controller to reduce noise when the full capacity of the fans. Though this appears to raise concerns about using a PWM type speed controller with brushless motor fans.

These controllers are available with remote control which appeals.

 

[r4dent]

In summary, some people think fans help, some think they don't and some have no opinion/

So, like almost everything else we discuss on this forum, you must make your own mind up.

 

[wildebus]

The descriptions on fans can be very misleading ref noise. I fitted this "KIMISS Side Air Vent Fan" and the 2nd bullet point says:

Quiet for a Peaceful Space ---- With its noiseless performance, this side air vent fan provides you with a quiet and tranquil space. You can enjoy a peaceful atmosphere without any disturbances or distractions, making it perfect for bedrooms, living rooms, and offices.​

​

But it is only noiseless if you are deaf or can turn off your hearing aids! Didn't matter to me as I fitted it to run when the Microwave Combo oven is on, and that makes enough noise to drown out the fan anyway (and given the power of the fan, no way could it be noiseless anyway).


FWIW, the fridge fan kit I fitted in my motorhome was the Titan kit which comes with a controller that you can put into manual mode and chose between 5 different speeds, or put into auto mode where the speed of the fan is determined by the temperature detected by the positionable sensor.
But this Titan kit (link here for info) was not cheap - paid £57 for it 5 years ago - and I really decided to get it rather than going the DIY route of PC fans + temp controller and on/off switch as I was keen to see if the advanced features were worth the extra cost (spoiler alert. IMO ... )

 

[Canalsman]

What you could add if you had a mind to is a simple temp controller that will turn the fans on and off at certain temperatures (that you chose). These are literally just a few pounds in price, would use the existing wiring you have in place and if you replaced your switch with a 3-way switch, you could select the fans to be ON, OFF or Temp Controlled.
I can give you more info and a link if this is of interest?

Yes please...

 

[MERL]

In summary, some people think fans help, some think they don't and some have no opinion/

So, like almost everything else we discuss on this forum, you must make your own mind up.

Well, I'm not a 'my mind is made up' sort of person.

 

[Pudsey Bear]

First, you'd need one anyway.

 

[Geek]

Originally, I fixed three computer cooling fans to the top vent, and they worked well for several years, but they were getting noisy as they got old. They simply prevented the fridge from struggling in hot weather.
I replaced them with Arctic Silent fans about five years ago. These are not silent, but they are way quieter. I think I fitted them in some vibration-absorbing way, but I forget the details. At five years old, they are still lovely and quiet.
They are wired through a speed control and temperature switch, which only runs the vent fans when the temperature inside the top vent is a bit high.
However, there is fourth fan: inside the fridge, stirring the air up. This runs through the speed control but not the temperature switch. It makes a really big difference to how well the fridge works when it is full.
Being a geek, I have the graphs.
I am a big fan of internal fridge fans. Some domestic fridges have them. Almost all fridges would benefit from them