Building fermentation fridges

[Professional beer tester]

Hi all,

Surely this has been discussed before, but I'd love to see how everyone has built their fermentation fridge in one place.

This video looks interesting – and looks like it would save a load of money.

 

[EvilTwin]

That is an awesome idea!

 

[Rocker1986]

I was lucky, we had an old unused fridge sitting around doing nothing which still works so I just got an STC-1000 and hooked it up to the fridge and Robert's your mother's brother.

 

[Spiesy]

• Bought a second hand fridge off eBay for around $80. It was a straight fridge, no freezer - in good working order.
• Purchased an STC1000, jiffy box and extension lead - made up a controller. Around $30.
• Purchased a ceramic heat lamp with clip-on attachment from eBay, similar to THIS. $50.
• Drilled a hole in the side of the fridge, ran STC and heat lamp leads through.
• Tested STC with fridge and heater outputs - using a lamp first (instead of actual appliances). They worked, so siliconed up the hole in the fridge.
• Built a compressor hump shelf for the fermenter to sit on, out of some left over bits and pieces, sealed the wood to prevent rot.

$160. Job done. Of course, if you already have a fridge, or access to a free one - it's an $80 excursion.

I like the idea of the ceramic heat lamp... no damaging UV rays, no dangerous portable heater in the fridge, with exposure to moisture - no direct heat that a heat belt or heat pad may offer, plus it clips on nicely to the shelves in the fridge door.

 

[Droopy]

Same, got a good cheap 2nd hand fridge, wired up the STC1000 controller and Fanny's your aunt.

 

[QldKev]

Not being negative on that original video but...

Being a modern fridge that does not have the rear external condenser, it is incorporated into the fridge cabinet. Housing the fridge cabinet into the wooden framing means it cannot exhaust the heat correctly and result in an inefficient fridge.

Then add in the design of the fridge is build to cool a given area, by increasing that area without increasing the cooling potential of the condenser means the fridge will need to work harder resulting in a hotter condenser area. The hotter the condenser becomes the less efficient the fridge becomes, resulting in the condenser being even hotter. So you result in a fridge becoming inefficient.

The two lots inefficient design means any initial saving are quickly offset by increased power consumption. Once the payback period has broken even you continue to pay higher energy usage for the life of the device.

edit:
As an idea here's my fermenting fridge using a 10 year old all fridge. The fridge is not housed in making it work harder, and is not cooling an area that exceeds it's design capacity. You can pick these up cheaper than what the bar fridge + timber + hinges + handles + insulation etc would cost. As a bonus it uses a lot smaller footprint than the chest style

 

[MastersBrewery]

Kev the PVC pipe is that moving air up or down?

 

[QldKev]

Kev the PVC pipe is that moving air up or down?

It blows upwards. My theory is it does not matter too much as long as you get the air moving.

That pic is old, I've mounted it to the door about half way up now, so the top is approx middle of the top fermenter, and the bottom is approx middle of the bottom fermenters. Then the fan is angled in the pipe so it blows towards the back of the fridge.

 

[Professional beer tester]

Some good advice Kev – just a few quick ones (as I've never had a controlled environment myself) – if the fridge is designed to run at 0-5º for its size and you're fermenting at ~11-23º, does that still affect the footprint?

Reason I ask is I have a (free) bar fridge that's around 900mm high but currently will only fit 1x15L fermentor with the carboy.

Also the fan – is that to recirculate the air to keep the temps more even? Is it on constantly or do you have it switched into your temp control?

I'm guessing being in QLD you don't have a heating element in your setup, any tips on that?

 

[QldKev]

Some good advice Kev – just a few quick ones (as I've never had a controlled environment myself) – if the fridge is designed to run at 0-5º for its size and you're fermenting at ~11-23º, does that still affect the footprint?

Reason I ask is I have a (free) bar fridge that's around 900mm high but currently will only fit 1x15L fermentor with the carboy.

Also the fan – is that to recirculate the air to keep the temps more even? Is it on constantly or do you have it switched into your temp control?

I'm guessing being in QLD you don't have a heating element in your setup, any tips on that?

A fridges efficiency is based on operational temperature difference. Say your average environment temperature is 25c, so 25-4=21 difference, but 25-12=13. So yes at fermenting temperatures there is no issue. If you are planning on using it only at fermenting temperatures you could increase the space to cool, allowing the same potential for insulation you could double the volume comfortably. A lot will come down to how efficient the insulation material is. But all my brews get cold chilled before kegging. So when you set the controller to <4c to chill the area/fermenters down is where you run into problems. Having cold chilled my beers for a few years I would never think about not doing it. My old fermenting fridge (soon the be salami fridge) is a 320L all fridge that would hold 2 fermenters comfortably. I picked it up from free cycle. Otherwise ebay has chest freezers and all fridges pretty cheap. A power usage meter would let you know how well the fridge is coping. I don't want to see anyone spending a lot of money on materials and after a year or so updating and wasting that money. Have a search on here there have been a few projects of the same nature, and also the 'son of a fermenter' projects that have limited usage lives.

The fan is just that to keep the air moving. A while back (in my old fermenting fridge) I measured the temperatures between the top and bottom fermenters. I found up to a 5c variation. With the fan running I find it stays within about 1c. I currently only have the fan running when the fridge is running. I just have a poweboard plugged into the Dixel (pre stc days).

Never needed heating here. It's currently 24.1c in the carport. Not too shabby for a winters day. If I did go heating I would use a reptile heat lamp
Holder
$8.88 http://www.ebay.com.au/itm/Light-Lamp-Holder-Stand-for-Reptile-Ceramic-Infrared-Heat-Emitter-EU-Plug-FV88-/141009880296?pt=AU_Pet_Supplies&hash=item20d4d804e8
plus 50w lamp
9.93 http://www.ebay.com.au/itm/50W-220V-CERAMIC-HEAT-EMITTER-BROODER-INFRARED-LAMP-BULB-REPTILE-GROW-mj-/130923595059?pt=AU_Lighting_Fans&hash=item1e7ba78533
I think the 50w would be heaps, but they come in 75w and 100w versions.
OR 100w version.
8.71 http://www.ebay.com.au/itm/High-Grade-Design-Black-100-Watt-Ceramic-Heat-Reptile-Bulb-Lamp-Lighting-D0X8-/231017053229?pt=AU_Pet_Supplies&hash=item35c9b07c2d

Have a search on here for the wattage. The lower the wattage you can get away with the smoother the heating will be to avoid peaks.


If you want a read, here is a thread where I measure some fridges etc in my house.

 

[TidalPete]

Kev,

I'm glad that I've found this thread whilst trawling for best ways to improve fermentations in my new (As in newly obtained 2nd-hand) Westinghouse all-fridge.

My really old Gorenji Pacific all-fridge finally karked it on Boxing Day, sadly taking my faithful Dixell with it on it's journey to Whitegoods Heaven & so I have decided to give all future brews the best possible fermentation I can provide in the Westinghouse all-fridge.

Am in the process of setting up a fan pretty much like you show in your pic in Post 8 (Have modified two shelves to hold the PVC pipe + added a 90 deg elbow to both top & bottom) but because my fan is 120mm I need to silicon on some sort of (120mm) square box to the end of the top elbow to hold it in place --- No worries there.
Am getting another TempMate to replace the Dixell & using a heat pad as the heating component as in my other fermentation fridge but the main reason for this post is to give you big up's :super: for your PVC pipe pic.
A truly great & inspiring idea! :beer:

 

[Thefatdoghead]

Indeed, Very efficient way of moving air Kev. Nice work.