Overflow Fridge/Freezer set-up

[geoffr]

I'm wondering how common our Fridge/ Freezer set-up is.

What we have is two compartments which are interconnected by two holes at the top of the compartments with a fan in one of them. The freezer side has a Evaporating Unit in it. The "Fridge" size relies on the fan to blow in cool air from the freezer side.

It's somewhat effective, but I'm currently working on a way to improve the "Quality" of the temperature on the fridge side.

How common is this?

[toddedger]

My spillover does not have a fan and it works well. I think the distance the spillover hole is from the bottom determines the fridge temp. you may need to lower your hole a bit to bring up the temp in the fridge side. mine is about 2.5"x3.5" and it's about 12" up from the bottom of the freezer.

[sailorboy1]

Originally Posted by geoffr

I'm wondering how common our Fridge/ Freezer set-up is.

What we have is two compartments which are interconnected by two holes at the top of the compartments with a fan in one of them. The freezer side has a Evaporating Unit in it. The "Fridge" size relies on the fan to blow in cool air from the freezer side.

It's somewhat effective, but I'm currently working on a way to improve the "Quality" of the temperature on the fridge side.

How common is this?

You have a spillover system. I have one in my boat and it works well.

The best thing I have done and that I feel improves the system is a fan inside the fridge side to circulate the air around. Other the side wall gets real cold and the temperature within the box is not even. I got a battery powered fan that is designed for this use, but plan to install a system powdered fan when I get around to it.

The other important thing is not to allow ice to build up on the evaporator walls in the freezer. This is all about having tight lids to keep moisture out and not to put open ice/liquid in the freezer (put some ice in there and watch it shirk as it moves to the evaporator).

The only other way to improve is to put in a separate compressor system for the fridge side.

[geoffr]

Thanks for the replies.

Our Fridge and Freezer are quite well insulated and seal well (in humid weather it's many months before I feel we need to defrost the evaporator).

Our two holes are quite high up and the Fan runs when the compressor runs. I'm thinking of adding a controller to have the Fan run all the time until a preset temperature in the Fridge is met. (This air movement should also help equalize the temperature in the Freezer which is currently rather uneven).

Image below (ignore the ice - this was when the compressor was broken years ago).

[sailorboy1]

My spill over fan has its' own thermostat.

[geoffr]

sailorboy1 - do you know where you got your battery powered one?

Have you found a 12V powered on with thermostat - I've done a quick look and only found them for over ~100... I can build one from scratch much cheaper with more "features"

[sailorboy1]

Originally Posted by geoffr

sailorboy1 - do you know where you got your battery powered one?

Have you found a 12V powered on with thermostat - I've done a quick look and only found them for over ~100... I can build one from scratch much cheaper with more "features"

I don't remember where I got the battery fan.

My boat came with the 12V/thermostat combo. I do have an electronic thermostat to replace the mechanical one I currently have. It was only like $20 and I got to allow better setting control, but I haven't installed it yet.

[wooden head]

My home fridge works this way but it has a door that opens and closes in ductwork between freezer and fridge to regulate temperature. Fan either pushes cold air around freezer or into the fridge when compressor runs.

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[Lucky]

Interesting discussion!
Our Belize is equipped with a freezer/fridge combo and a single 45mm hole between them and a thermostat controlled fan. This sounds like the same as some of you have onboard. The problem I face is that there is no return hole so that when the fan operates when the freezer is in use it inevitably sucks in warm moist air and the evaporator freezes over quite quickly.

In your folks opinion should the return hole be same dia as the supply air hole? And should it be at the same hight? The supply hole sits 30mm below the top insulation inside the freezer.

All good advise is received in gratitude.

Happy lead free sailing from Lucky

[a64pilot]

Assuming you have a solid wall between the two sides and you had a hole in the top and bottom, that should set up a convection that will circulate air without any fan. Have a way to gradually block the hole on the bottom to block that convection and you have a way to vary temp in the fridge side with no electricity or moving parts to break.
Due to not having any kind of fan, you may need more or bigger holes though.

Beauty of the fan and thermostat is it's set it and forget it, plus if you add a bunch of warm food in the fridge, the thermostat will cause the fan to run until set point is reached, so it will cool back down quicker. Depends I think on if you like elegant, complicated systems, or simple systems, accepting the simple system works, but not as well as the elegant complicated one. If I had the fan and thermostat and it was working correctly, I wouldn't mess with it, but know how to set up a convection in case you get somewhere and it quits and parts aren't available.

[a64pilot]

To keep from forming a slight vacuum on one side of your box, I'd add a return hole of the same size as the one you have. I'd put it at the same height in order to not set up a convection.
If yours is an icebox conversion, there is probably a drain, if there is a drain, that is a source that warm, moist air could be coming from to frost your evaporator, you could plug it, or set up a P trap in the drain line

[Richard Kollmann]

Originally Posted by geoffr

I'm wondering how common our Fridge/ Freezer set-up is.

What we have is two compartments which are interconnected by two holes at the top of the compartments with a fan in one of them. The freezer side has a Evaporating Unit in it. The "Fridge" size relies on the fan to blow in cool air from the freezer side.

It's somewhat effective, but I'm currently working on a way to improve the "Quality" of the temperature on the fridge side.

How common is this?

I use my forum and web site to add revisions to my books. There are 11 ways to improve your refrigerator's performance with fans on my web site and at least 3 on spillover boxes. Kollmann Marine

[a64pilot]

RV stores carry battery powered fridge fans, I've never tried one but have seen them.

[sailorboy1]

Originally Posted by a64pilot

RV stores carry battery powered fridge fans, I've never tried one but have seen them.

I have one, works great! The temp is staying more even and crossover fan barely even runs anymore.

[geoffr]

This page has some good information I found which you might find useful:

Kollmann Marine