Mini Fridge DIY Ferm Chamber Question

So i have read a few threads on here about making a ferm chamber with a mini fridge.
I have recently acquired me one...Got a smoken deal.

Question i had here is, With a mini fridge ferm chamber....
How far can you go before your need anouther fridge at the other end of the chamber.

If i have lost you...Think of this build here.
https://www.homebrewtalk.com/f51/yet-another-under-workbench-fermentation-chamber-build-133970/

Basicly...How long could you go before one end would not be cool enough to keep carboys/ hops cold?

Reason i am looking for longer than normal. Well, I am stepping up to 20 gal batch's soon. 2nd, I am getting tired of the water bath with frozen water bottles day and night.

*bump*

Nobody has any comments?

There are a lot of variables to consider here.

How big is the fridge?

How well does it work as-is?

What kind of insulation would you be using? R-value?

How cold do you need to get it? Lagering?

What is the ambient temp where you are going to put it?

There are other things to consider, but basically it boils down to how much heat can the compressor effectively remove without being overburdened. How long were you planning on making it (compared to the existing length). I wouldnt really want to go much more than double or triple the existing volume without adding one on the other end.

Oh and it seems like a PC fan or something to circulate air inside is a must.

I used a mini and I installed a small fan in the chamber to circulate air around inside the space. This adds some amount of heat to the chamber, but the evaporator and condenser seem to be doing a fine job at this time I am maintaining 53 degrees during primary fermentation. My thermostat on the unit can be lowered about 35% more, so I should also be able to do a decent job of lagering. If you plan to make you chamber as large as the one indicated in your post, I would suggest using a bigger condensing unit and evaporator.

I do not have any pictures to post of my unit at this time, but I will snap a few shots and post them later this evening.

Good luck with your build.

Salute!

Fridge Size, I have a magic chef fridge 33" tall 17" wide. Its currently my Hop A Rator...but thinking of either converting or finding another one.

For insulation, I was thinking of the foam stuff thats like 2 inch's think.

For capacity i was thinking 4 carboys. Hopefully room to exspand in the future.
I am fermenting in my basement, But when they are in full swing its not cold enough to keep the temps around 70.

6 1/2 gal carboy is roughly 12" wide so, That makes it 4 1/2-5 feet long. Unless i can make it 2 feet wide and have multiple fans in there and be able to go a shorter distance, with more holding power?

Lagering, No just want to keep a constant ferment temp. Current temp in basement is 74.
I am stepping up to 20 gal batch's so thats why 4 is how many i need to hold, More would be nice...