Top freezer fridge conversion

Has anyone convertered their fridge for fermentation + working top freezer?

I saw this blog but cannot find any other examples.
http://www.eckraus.com/blog/convert-refrigerator-to-fermentation-chamber

Haven't seen anyone successful at that, and I don't think there's much chance of having a "working top freezer" that actually freezes food or whatever when the food section is running at fermentation temperatures.

I've been running a pair of 17cf top-freezer fermentation fridges for years, they're not tall enough to cut the freezer floors out to stack more fermenters, so I just resigned myself to having a few cubic feet of dead space...

Cheers!

day_trippr said:

Haven't seen anyone successful at that, and I don't think there's much chance of having a "working top freezer" that actually freezes food or whatever when the food section is running at fermentation temperatures.

I've been running a pair of 17cf top-freezer fermentation fridges for years, they're not tall enough to cut the freezer floors out to stack more fermenters, so I just resigned myself to having a few cubic feet of dead space...

Cheers!

Click to expand...

Alright, maybe I just convert it to a kegerator instead.

Thanks for the info.

I think I have just successfully converted a top freezer Fisher and Paykel activesmart to control the fridge part but keep the freezer working.
I'm currently doing some tests on it but if I'm happy I will do a write up.

Subscribed. I have a F&P fridge freezer though my freezer is on the bottom. Will be modding it on the weekend hopefully. Mine has a fan which blows air from the freezer into the fridge. I plan to control this fan using a stc1000. Freezer I think could run normally but I need it at 0c for bottle lagering. Hoping this should be straightforward.

I used my STC1000 to modify the NTC (Temperature sensor) input to the fridges controller. just needed two resistors and some wire. I'm just encoding a video to put on youtube now.
Just tell the fridge it is either -4C or +25C and let the fridge do the rest, freezer stays nice and cool. mines an early model activesmart although probably all similar. When the videos up I will add a link

Mine uses a fan the same as yours Sadu so probably very similar. Really easy to get to the wires for the mod too

Here is a link to a video I threw together about my hacking of a F&P activesmart to keep the freezer but end up with a fermentation chamber in the fridge part controlled by an STC1000

I've been enjoying a few homebrews in celebration and I'm still getting to know the video editor software Im using..
I know I say increase when I meant decrease at one point but the key information is there.
Maybe I will edit it better later or write it up but in the interests of shariung the information the video is up at:
https://youtu.be/c2pzDDjFR9U

I'm real glad I found this thread. I was just going to connect external 12v to the fan and use the STC1000 to control it, then another STC1000 on the unit's power cord to control the freezer temps. This method looks way cleaner. Hopefully I can apply the same logic to the freezer thermistor as well. How did you know which wires to cut? Was there a wiring diagram sticker on the fridge or is there a standard F&P master plan available somewhere?

Sparkncode said:

Here is a link to a video I threw together about my hacking of a F&P activesmart to keep the freezer but end up with a fermentation chamber in the fridge part controlled by an STC1000

I've been enjoying a few homebrews in celebration and I'm still getting to know the video editor software Im using..
I know I say increase when I meant decrease at one point but the key information is there.
Maybe I will edit it better later or write it up but in the interests of shariung the information the video is up at:
https://youtu.be/c2pzDDjFR9U

Click to expand...

Nice job! I'm glad it worked out.

Sadu said:

Hopefully I can apply the same logic to the freezer thermistor as well. How did you know which wires to cut? Was there a wiring diagram sticker on the fridge or is there a standard F&P master plan available somewhere?

Click to expand...

I found the service manual for a similar manual googling for "activesmart service manual"

I have attached a couple of images.
On the connector they use PC and FC PC = produce compartment AKA fridge (the one I cut) and FC is the freezer compartment FC ( two wires on the opposite end of the connector to the ones I cut).

You might need to change the resistor values as per the table I put in my video to fake the freezer as it will want a lot lower than -4C to cut off but just choose two resistors to get suitable temperatures sent to the fridge and it should work.

When testing be aware that it doesn't come on exactly when the STC1000 relay switched, there is a maybe 10 second delay, I think the fridge controller has a slow filter on the temperature inputs.

I think the fridge can possible detect open or short circuits on those wires so if it starts beeping turn it off for a bit, fix the problem and re power.

While I wait for my mash to complete a bit of an update:
I'm confident my modification is working well now on my fisher and Paykel fridge/freezer.
I would think this method would work with any fridge freezer that uses thermisters rather than traditional thermostats.
My fridge uses NTC thermisters, i.e. the higher the temperature the lower the resistance.

You would need to measure the thermister resistance at a couple of temperatures though to work out the resistors needed but that isn't hard.

My bread etc in the freezer has been fine all week while the carboy has stayed at various temperatures I have set it at. The comprtessor is not running excessively Also adjusting the freezer temperature using the fridges settings still works. The fridge microcontroller seems to have its own protection for the compressor but I chose to set the STC1000 for quite a long time just in case.

Soooooo, I modded my fridge tonight. Took about 2-3 hours including wiring up the STC-1000. Gotta give credit where due, Sparkncode, your instructions were super helpful and the wiring layout for your fridge looks the same or very similar to mine. Thanks so much for your posts and video, also the OP for that initial link.

I cut the brown wires and connected those to the STC-1000 with the same resistors as yours - seems to work. I went a step further and put a plug/socket on the brown wires in the fridge controller so if I want to turn it into a normal fridge again I can reconnect the fridge thermistor without having to solder anything.

I got a lager planned for Sunday so I'm going to see how this goes at 10c/50f. Feeling like this is a big step up from the swamp cooler. If all goes to plan I'll do the same hack on the freezer compartment (white wires I believe). As you say, will need to use different resistors.

Great, pleased the info was helpful.

I was a bit rough and just tucked the cut off wires out the way but your plug/socket sounds like a good solution, I guess if anyone wanted a switch is pretty easy to add too.

It will be interesting to see how well your fridge handles both the fridge and freezer being manipulated.

I think your fridge should work well at 10C for your larger as I did a few tests with a 11.5L PET carboy full of water at 10C and it worked well as long as I had the temperature sensor taped to the carboy and not hanging in the air.

Good luck with your larger, I haven't done one yet but I guess now I have a fermentation chamber I should have a go some time.

Glad to see this is working! Are you guys doing an ohm test on the theromresister to determine which resister to use?

I measured the resistance across my fridge thermistor and it came out at 4 ohms / 7 degrees or something like that. Pretty much where it should be if you look at that resistance table in sparkncode's video. So I figure I'm lucky enough to be using the same or similar F&P Activesmart so I saved myself the math and used the same resistor values. Seems to work so far.

Not sure when I'll do the freezer - I just swapped a batch of homebrew for a big bag of goose / duck / chamois / venison / wallaby delicacies so I'm thinking it might be safer to not cock things up with a DIY project when the freezer is full of treats.