Fermwrap or flexwatt for heating - Home Brew Forums
Home Brew Forums > Home Brewing Beer > DIY Projects > Fermenters > Fermwrap or flexwatt for heating

Reply
 
Thread Tools
Old 01-22-2013, 11:45 AM   #1
New_Climber
Recipes 
 
Oct 2011
Kalama, Washington
Posts: 70
Liked 2 Times on 2 Posts



I am in the process of building a fermentation chamber using a 4.3cuin fridge..

Question is about heating and what to use...

Seems like either the flexwatt on the door or wall....

or

A FermWrap around the carboy...

I am not sure which I should go with. I have a fan mounted in the fridge so I will have good air circulation...

One question about using the FermWrap...do I still tape my temp probe on the side of the carboy?? I would assume I don't want it under the FermWrap being that would give a false reading to my controller right?

So, which one would you go with?



 
Reply With Quote
Old 01-22-2013, 03:51 PM   #2
CapnBry
Recipes 
 
Oct 2012
Tampa, Florida
Posts: 38
Liked 6 Times on 4 Posts


Wow a 4.3 cubic inch fridge? It must be adorable!

FermWrap is Flexwatt so the choices are the same. The fermwrap is just some Flexwatt with all the connectors and plug pre-installed. If you wrap your carboy with either one, you don't want to tape your temperature probe under or over it unless you devise some sort of heat-resistant insulation.

Considering you can only fit one carboy in the fridge, I'd recommend just mounting it to the fridge itself, on account of not having to do the procedure of wrapping the carboy when you put it in and unwrapping it when you take it out. This assumes you're not putting your fridge somewhere where it gets insanely cold though.



oldstyle69 Likes This 
Reply With Quote
Old 01-22-2013, 05:19 PM   #3
alien
Recipes 
 
Apr 2012
Philadelphia, PA
Posts: 1,235
Liked 67 Times on 58 Posts


If you are mounting the heating element to the fridge itself, you could just use an aluminium clad resistor.

 
Reply With Quote
Old 01-22-2013, 06:14 PM   #4
doctorRobert
Recipes 
 
Apr 2010
Sharon, MA
Posts: 1,005
Liked 38 Times on 26 Posts


paint can with a light bulb in it
__________________
Yo, What's Wrong With The Beer We Got? I Mean the Beer we got drank pretty Good Don't It? I Ain't Never Heard nobody complain about the beer we have..... It Drank Pretty Good. Budweiser...What's the name of some of them other beers ?

Arrheinous Likes This 
Reply With Quote
Old 01-22-2013, 07:17 PM   #5
BadNewsBrewery
Recipes 
 
Oct 2012
Severn, MD
Posts: 1,248
Liked 129 Times on 103 Posts


I grabbed some heat tape from ReptileBasics and wrapped my two carboys. Use a thermowell to get accurate internal temps. Works great.
__________________
Building a Bad News Brewery - eHERMS

2014 - 70gal
2015 - 72gal

 
Reply With Quote
Old 01-23-2013, 03:10 AM   #6
New_Climber
Recipes 
 
Oct 2011
Kalama, Washington
Posts: 70
Liked 2 Times on 2 Posts


Quote:
I am in the process of building a fermentation chamber using a 4.3cuin fridge..
Sorry...yea, that was pretty funny...ment to say 4.3cuft

Quote:
If you are mounting the heating element to the fridge itself, you could just use an aluminium clad resistor.
I have not read how to do this...can you give me some details??

Yes, my chamber is in my garage where it does get pretty cold. I was thinking about mounting the fermenting wrap on the door and maybe on the walls. How do I know how much I need?? My garage is about 55deg right now..

 
Reply With Quote
Old 01-23-2013, 03:12 AM   #7
New_Climber
Recipes 
 
Oct 2011
Kalama, Washington
Posts: 70
Liked 2 Times on 2 Posts


Also wanted to ask if the thermowell will work with the STC1000 probe...

meaning is the thermowell big enough to slide the probe down...

 
Reply With Quote
Old 01-23-2013, 07:36 AM   #8
alien
Recipes 
 
Apr 2012
Philadelphia, PA
Posts: 1,235
Liked 67 Times on 58 Posts


Quote:
Originally Posted by alien View Post
If you are mounting the heating element to the fridge itself, you could just use an aluminium clad resistor.
Let's say you want 20 W of heat. Get an old laptop power supply. Let's say it provides up to 3 A at 12 VDC. The first thing you need to calculate is how much current you will need at 12 V to supply 20 W of heat:

P = I * V (Power = current * voltage)

So to provide 20 W of heat you will need 20/12 = 1.66 A at 12 V. That is less than 3 A so the power supply can provide it. Next you need to know what value of resistor to choose.

V = I * R (Voltage drop = current * resistance)

You want a resistor that will drop 12 V when passing 1.66 A of current through it, so it will need to be 12 / 1.66 = 7.2 Ohms. Buy an aluminium clad resistor rated as close as possible to 7.2 Ohms that can handle at least 20 W. In this case, the closest you value you can easily get is 6.8 Ohms at 25 W. That's OK, but 6.8 Ohms at 50 W would give you more of a margin.

Now to get your 20 W of heat (actually 21.2 W) just connect your 6.8 Ohm resistor across the terminals of the 12 V power supply.

Don't hook up a resistor to directly to the mains electricity. Use a low voltage power supply.

 
Reply With Quote
Old 01-23-2013, 08:53 AM   #9
worxman02
HBT_SUPPORTER.png
Recipes 
 
Jan 2007
Posts: 232
Liked 19 Times on 16 Posts


You can also just get a ceramic reptile heating bulb and wire up a power tool cord to a lightbulb base. That's what I did and it is nice and compact and portable. I bought a 150W bulb from Amazon and it kept my 5 cu.ft chest freezer at 65F while my garage was mid 30s.
__________________
Brewing Soon: Oatmeal Raisin Cookie Amber Ale
Primary: None
Secondary: None
Kegged: Scottish Pale Ale (Scottish 80/- with added Hop Tea.
Bottled:Pumpkin Ale & Mcquaker's Chocolate Oatmeal Stout
Drinking: Above & HUB IPA & Dechutes Black Butte Porter

 
Reply With Quote
Old 01-23-2013, 02:28 PM   #10
Huaco
HBT_SUPPORTER.png
 
Huaco's Avatar
Recipes 
 
Dec 2011
Just south of Cow Town, Tx
Posts: 1,375
Liked 141 Times on 88 Posts


Quote:
Originally Posted by New_Climber View Post
Also wanted to ask if the thermowell will work with the STC1000 probe...

meaning is the thermowell big enough to slide the probe down...
I am using the 1/2" OD thermowell from StainlessBrewing.com WORKS GREAT!

Also, I am using the reptile basics 12" heat tape wrapped around my large malt drum fermentor... I have multi-temp control in my ferm chamber and right now, I am lagering one a beer at 37 and have an ale (Dus Alt) fermenting away at 60*F. The tape give a NICE GENTLE heat to the carboy.

See my signature for other details but here is a shot of the heat tape wrapped as well as the thermowell to accommodate the STC-1000 probe. I have since adjusted the heat tape wrap to be wrapped more straight and not spiraled. I noticed it was actually spiraled up above the wort level at 11 gallons.



 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
DIY - Fermwrap help kevinb Fermenters 10 10-21-2013 10:03 PM
Fermwrap - 2 for 1? BoogieBrandBooze Fermenters 36 03-27-2013 07:39 PM
Trouble shooting "heat tape" (flexwatt/fermwrap) GhettoDickens Equipment/Sanitation 0 03-10-2012 07:20 PM
Using a Fermwrap all by itself!!! Taygel Fermentation & Yeast 5 04-01-2011 04:37 PM


Forum Jump