Top Freezer Question

[Airborneguy]

I wasn't sure where to put this one... here goes.

My newest wacky idea:

I want to open a port between the top freezer portion of my fermentation refrigerator to take advantage of the much colder air coming from that area to achieve a lower temperature in the fridge portion where my fermentations and lagering happens.

Is there typically coolant lines in this area? Has anyone done this? Creating a hole is simple enough, I just don't want to hit anything.

 

[day_trippr]

All but exotic top-freezer fridges generate all of the "cold" required in the freezer and then duct (passively or with a fan) that cold air evaporator output into the fridge (food) compartment as needed, firing up the compressor as required.

So, pretty much already doing what you're thinking.

You'll often find an adjustment mechanism in the freezer to set how much cold air gets sent into the food compartment...

Cheers!

 

[Airborneguy]

This wouldn’t bring more cold air down? I already have the temp set as low as possible. It touches 33 but loses it quick. Probably averaging at best 35. I want lower.

 

[mac_1103]

Point is that there should be a duct already. Maybe if you can find it you could make it bigger? Or add a fan if there isn't one? Or replace the fan with a bigger/better one?

 

[day_trippr]

I already have the temp set as low as possible. It touches 33 but loses it quick. Probably averaging at best 35. I want lower.

If the fridge thermostat has bottomed out it won't make a lot of difference how large/active the ducting from freezer to fridge is: when the thermostat reaches its limit, the unit will shut down the compressor and wait for the next cooling cycle.

There is a thread that illustrates how to adjust a mechanical (bulb and capillary) fridge thermostat to change its range. Typically done to raise the thermostat's control range, you could go the other way a few degrees. But I wouldn't push it more than that.

Found it here: https://www.homebrewtalk.com/thread...tat-to-32f-eliminate-external-control.249612/

Alternatively, one can jump around the oem thermostat allowing control of the unit via its line cord with an external device (eg: Inkbird ITC), with which one could then drive the compressor at will...

Cheers!

 

[Airborneguy]

If the fridge thermostat has bottomed out it won't make a lot of difference how large/active the ducting from freezer to fridge is: when the thermostat reaches its limit, the unit will shut down the compressor and wait for the next cooling cycle.

There is a thread that illustrates how to adjust a mechanical (bulb and capillary) fridge thermostat to change its range. Typically done to raise the thermostat's control range, you could go the other way a few degrees. But I wouldn't push it more than that.

Found it here: https://www.homebrewtalk.com/thread...tat-to-32f-eliminate-external-control.249612/

Alternatively, one can jump around the oem thermostat allowing control of the unit via its line cord with an external device (eg: Inkbird ITC), with which one could then drive the compressor at will...

Cheers!

Hmm. Is the thermostat typically in line with the power source similar to a resister in REX door systems? I’m familiar with that set up and could easily bypass the thermostat to wire in my inkbird if it is similar.

I’m new to electric but learning fast.

 

[day_trippr]

Definitely a mechanical (pressure) switch placed in-line between the line cord "hot" and the compressor "hot" input. Typically you remove the cover off the thermostat in the food compartment and find three wires: a green/yellow safety ground attached to the metal body, a black wire from the line cord plugged on one lead, and a red wire heading to the compressor plugged on the other, switched, lead. You can pull the black and red wires off and connect them together, then plug the line cord into an external controller and place its temperature sensor inside the food compartment.

Or do the adjustment thing. User choice

Cheers!

 

[vmaxept]

Yes , this is what I did. I set the internal thermostat to lowest cold. Use the inkbird . Cut 2 holes in floor of top freezer to fit 2 computer fans one blowing down one blowing up. Power with a 6vdc power block. Added 2 fans on the bottom of fridge floor. Inkbird does hot/cold. Installed a 250watt table heater on floor of fridge. No mods to fridge thermostat. Added 2 probe temp gauges. Did not drill holes in side to route fan wires, just close door. Freezer fans, route wires thru the ice maker holes. Inkbird probe passes thru top freezer to fridge just let it hang. There are no cooling lines in the walls or freezer just wires Works great

 

[Airborneguy]

This is what i need to do! How much colder does the main compartment get?

 

[vmaxept]

With all the mini fans the temp in the upper and lower chambers is the same. Except when the fridge runs then the upper is a few degrees colder but balances out to the same. I mostly brew ales in this fridge set temp to 66 to 68 . If fermenter surface temp goes to 69-70 I drop the internal temp to 66 to keep the active fermenting temp under 70. Then set up to 70 for balance of time I had 2 of these, worked great, one for ale one for lager. one unit -old- compressor froze .

 

[day_trippr]

I think what @Airborneguy was looking for is what your lowest chamber temperature can now be with your fridge mods.
I'm guessing as the oem thermostat is still active the lowest temperature is essentially the same as before...

Cheers!

 

[Airborneguy]

So I started this project today… i’ll try to detail my progress later.

 

[marc1]

I wasn't sure where to put this one... here goes.

My newest wacky idea:

I want to open a port between the top freezer portion of my fermentation refrigerator to take advantage of the much colder air coming from that area to achieve a lower temperature in the fridge portion where my fermentations and lagering happens.

Is there typically coolant lines in this area? Has anyone done this? Creating a hole is simple enough, I just don't want to hit anything.

I did this. Works great. I have an inkbird set up to the fridge plug. I could freeze the fermenter if I wanted to. Also have more headroom.

 

[Airborneguy]

I did this. Works great. I have an inkbird set up to the fridge plug. I could freeze the fermenter if I wanted to. Also have more headroom.

Cut the floor of the freezer completely? Wow nice.

 

[marc1]

Cut the floor of the freezer completely? Wow nice.

An angle grinder works wonders.

 

[Airborneguy]

My progress so far. I have CPU fans and a power source arriving today. I just need to figure out a splitter that fits on the inkbird to plug them inline with the fridge power on the cooling side.

My heater is a shop light. It’s worked great so far. I will likely upgrade that at some point as well and route the cord through the side once I do.

 

[Airborneguy]

Project completed. It is holding steady at 33 now easily. Here’s what I did:

1. Hung the inkbird from a hook on the side of the fridge.

2. Routed the temp probe through the side wall.

3. Routed the shop light (heater) power cord through the sidewall. I cut it and spliced to avoid a large hole.

4. Cut two 2” squares in the floor of the freezer.

5. Routed power cord for fans through sidewall. Used adapter to plug in series with fridge power on Cooling side of inkbird.

6. Mounted two CPU fans over 2” holes. One blowing into fridge compartment, one pulling air up into freezer compartment.