# Inkbird Itc-308 alternative to Coolbot?



## we5inelgr

Hi forum,

I'm building a ~185 cu ft coldbox for winemaking / wine storage (aging) for my garage in N CA. Ambient temp in the summer, early fall is often high 80's to mid 90's. The box is insulated and will be cooled using a 6150 BTU window a/c unit (got a great deal on it, otherwise, would have gone with a 5k). 

It's nearly completed, I tested it the other day and got the box down to 62 F fairly quickly then the a/c cycled off.

I'd like the get the a/c to cool down to 55 - 60 F. I'm not an electrician, nor electrically inclined so building something from scratch isn't my cup o joe. I'd also like to stay away from dropping $350+ on a coolbot which I know would accomplish what I'm looking for.

With that in mind, would the Inkbird Itc-308 be a viable alternative to a Coolbot for getting the window a/c unit to cool lower than it's factory minimum (~62 F)?


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## Kraffty

If you haven't already done so you might check out Norcal's posts on then same subject. 
Mike


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## mainshipfred

There some refrigeration people out there that know more then me so they may jump in. I never researched the Coolbot but I believe they only work with certain AC units. I use the Inkbird in a different application and love it. To your question, the temperature control on an AC unit is basically a switch. To use the Inkbird to will have to make the AC unit so it never shuts off. This done by connecting the two wire going to the temperature control. Then plug the Inkbird to the wall and the AC to the cooling outlet on the Inkbird. FYI, the air from an AC unit normally comes out at 55* so that will be pushing the limit. As I said, someone else may jump in.


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## NorCal

Hey @we5inelgr, I'm in the Sierra Foothills and found myself in your same situation. How to store wine in heat of the summer months, which lead me to build my wine box. Here was my build thread. Sorry about all the pictures missing...darn PhotoBucket changed their policy and it is thousands of dollars a year now to link pictures.
PM your email and I'll send you a pdf of the winemaker magazine article.

In addition to being a controller, the coolbot has a heater element that tricks the AC unit into thinking it is warmer than it really is. The controllers simply turn the unit on/off based on the temperature. I made my own controller to turn my window AC unit on/off out of an $8 ebay controller.

I actually have a coolbot, that came with the equipment I bought, but have never used. I read a lot of UCD papers on wine storage and impact on aging due to temperature. I feel comfortable with the wine I make and the length of time that I plan on aging them, that if I never let the wine get above 69 degrees, that I am comfortable with that.

Welcome. Here is an early pic of my wine box.


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## we5inelgr

Thanks for all the reply's, much appreciated!

I've confirmed that, while my window a/c unit is digital, it does have the temperature sensor situated just behind the removable filter.

Sounds like all I need to do is relocate the a/c sensor to the outside of the cold box and then use the inkbird (& it's sensor) on the inside of the cold box and plug the a/c into it.


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## NorCal

A few questions.
- can you relocate the sensor?
- if you hard cycle the unit, does it remember your last setting?


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## Johny99

Not familiar with either, but check the current rating, Amperage, of the inkbird. A/c units can draw a lot of current, particularly when the compressor kicks in. You might want to put a relay in to protect the inkbird.


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## balatonwine

Just saying: temperature is only half of the issue. Humidity is also important. Especially if you are aging in oak. An "ideal" wine cellar will have humidity above what you want in your home. And AC can negatively affect humidity.


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## AZMDTed

we5inelgr said:


> Thanks for all the reply's, much appreciated!
> 
> I've confirmed that, while my window a/c unit is digital, it does have the temperature sensor situated just behind the removable filter.
> 
> Sounds like all I need to do is relocate the a/c sensor to the outside of the cold box and then use the inkbird (& it's sensor) on the inside of the cold box and plug the a/c into it.



I am very satisfied with my inkbird. I suggest that you get one, relocate the thermocouple, set the unit on max and then run in on the ink bird to see if it works. With a digital readout it may give you a problem. If it does you may still be okay if you can bypass the adjustment which should leave it on all the time there's power, and the inkbird will control when there is power.

I believe that you can google how to bypass the controller.


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## AZMDTed

balatonwine said:


> Just saying: temperature is only half of the issue. Humidity is also important. Especially if you are aging in oak. An "ideal" wine cellar will have humidity above what you want in your home. And AC can negatively affect humidity.



This is true. The good news about oversized AC units is that they tend to reach to the cool point before sucking all the humidity out as a normally sized AC unit is designed to do. Nonetheless, in summer time I still need to run a humidifier in my wine room to keep the humidity at 70%, which is higher than the ambient humidity anyway.


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## AZMDTed

Johny99 said:


> Not familiar with either, but check the current rating, Amperage, of the inkbird. A/c units can draw a lot of current, particularly when the compressor kicks in. You might want to put a relay in to protect the inkbird.



I believe the inkbird is rated at 1500 watts which has been plenty for 5K BTU AC unit. I think the compressor surges to about 1000 and then the unit runs somewhere about 350W. I could be wrong on those numbers it's been a while since I checked them. But the bottom line is the Inkbird has handled mine with no issues at all and is a great value.


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## Boatboy24

Those of you using window AC units, how are you handling the (presumably) low humidity?


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## Smok1

Im an AC mechanic, you can get that window shaker to cool to 55f fairly inexpensivley by picking up a honeywell temp controller like the one pictured below from your local refrigeration/hvac wholesaler. No matter if your window shaker has sensors, motherboards, or any other fancy features the basics are a condenser fan, evap fan and a compressor which will be controlled by either a contactor or a relay, all you need to do is jump the power through your original temp switch, then break a leg on the contactor controlling the compressor and blower motor and install the honeywell temp controller. The temp controller will have 2 sets of contacts in it, normally open and normaly closed, you need the open on temp fall one, ask the wholesaler for the right one. Just tell them what your doing and they will set you right up.


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## mainshipfred

Boatboy24 said:


> Those of you using window AC units, how are you handling the (presumably) low humidity?



Jim, as Ted said earlier the faster you cool down the room the less humidity you lose. Especially keep in mind a small 5btu unit is meant to cool a 500 sf room so our 100 sf rooms should cool prety quickly.


Just an FYI Inkbird 308 is 1000 watts and the 310 is 1200.


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## Smok1

Forgot to post
The picture.


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## Smok1

They make fancier ones bit thos is all u need


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## J-Hat

Boatboy24 said:


> Those of you using window AC units, how are you handling the (presumably) low humidity?



Even with an AC unit I'd be luck if my humidity dropped below 65%. That lovely SE Texas Weather.


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## ibglowin

I have an inexpensive humidity gauge in the winery. It's usually around 35% in there even though it may be 10% humidity outside. It goes up to 45% in the monsoon season. Hasn't affected my corks and some are now 8 years in the bottle.


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## AZMDTed

ibglowin said:


> I have an inexpensive humidity gauge in the winery. It's usually around 35% in there even though it may be 10% humidity outside. It goes up to 45% in the monsoon season. Hasn't affected my corks and some are now 8 years in the bottle.



I read an interesting article about humidity and wine. Their study concluded that somewhere about 65-70% is ideal. Not so much from a cork's stability perspective but rather from evaporation. Under that amount and the water in the wine is primarily effected by evaporation. But over that range the alcohol tends to evaporate more. So it was a matter of keeping balance.

Whether that matters for a wine only kept 2-3 years I don't know. Likewise, there may be some benefits by evaporating more water at the expense of a minimally higher ABV.


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## Bembel

*DIY Coolbot alternative*

If you connect an AC to a temp controller without contingency to control the ice build up on fins within a day your AC will be a block of solid ice

No need to hook your AC up to another temp controler, you can mimic the coolbot with two inkbirds / STC controllers connected in a series and a 5 volt light bulb and 5 volt power supply - 40$ at most

This is from a similar thread in HomeBrewTalk - I wish I had thought of this!

Makeshift Coolbot 

It uses two STC-1000 units in series, as stated in a previous post, but instead of connecting the a/c unit, the STCs trigger a small 5v light bulb.
I used two STC-1000 units, a 5v light bulb and a 5v power supply (old cell phone charger).
First, I connected the +wire from the power supply to the light bulb. Then ran the -wire to the first STC COOL relay; from there it goes to the second STC's COOL relay in series, and finally to the other pole in the light bulb. Cover the light bulb with foil, attach the A/C unit's temp probe to this fixture and cover with foil again.
Place the temp probe of either STC inside the A/C's evaporator fins, set the STC to 32. This will prevent the evap from freezing out. Use the other unit's probe as your room temp sensor, set it to whatever your target temp is.
Set your A/C to the coldest setting.
The idea is, just like with the coolbot, to trick the A/C into thinking the room is warmer than it really is, by heating the A/C's probe with the light bulb or whatever heater you want to use, while the STCs monitor both room and evaporator temperature and relay or cut power only to the light bulb. This way there's no need to mess with the A/C unit in any way, and you can use whatever A/C you want.

Good luck, when it comes to DIY projects involving fermenting, the beer nerds web sites are full of info!


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## AZMDTed

I've never come close to having an ice issue in my 16 months of use of my inkbird on a 5k btu window AC unit. During the hottest months the AC only runs for about 3 minutes every half hour. Gets the room back to 58 just fine. I don't think it's on long enough to ice up.


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## we5inelgr

AZMDTed said:


> I've never come close to having an ice issue in my 16 months of use of my inkbird on a 5k btu window AC unit. During the hottest months the AC only runs for about 3 minutes every half hour. Gets the room back to 58 just fine. I don't think it's on long enough to ice up.



In my limited time using the Inkbird, ~3 months, I too have not had any issues with ice. In fact, I've never seen any evidence of anything that looks like ice building up and it was over 100 in my garage (where my coldbox is) for several weeks while I was running the AC at 65.

I think it's true that if an "oversized" AC unit is used, it gets the little room cooled down quick enough that icing doesn't become an issue.

Love the Inkbird. Great price comparatively and performs exactly as expected.


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## Bembel

I am in shock!

How big are the cold boxes you are cooling?

I am using a 5k BTU GE analog A/C to try to chill a tightly sealed off and well insulated corner room of my cellar, its probably 12 feet by 6 feet, with a 10' ceiling, when I moved the thermal wire /thermostat bulb away from the fins to the side of the AC to trick the unit to keep cooling and left it on for just 12 hours the entire unit was encased in ice, this is in Boston in 75F temps - not humid. Im amazed that using an Inkbird without a second temp controller linked in series to shut it off when the fins get below say, 40F, has not caused the same ice.

But the point of my response, you dont need to spend $300 on the Coolbot, you can get a room down to 35F using Inkbirds to accomplish the same thing with a small heater to trick the thermostat, OR , you can build you own using an Arduino and some open source code, The Inkbirds are simpler


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## Bembel

*What am I doing wrong?*

So I disconnected both inkbirds (one that keeps shuts off when the fans start to freeze) and just plugged the AC into one, set the temp at 55F and kept the heating on the AC thermostat so it would run and the inkbird would shut it off at 55F, and within 90 minutes the fans were covered in ice?

Im at a loss????

Its currently 62F outside

beginning to thing the GE AC is lacking, but my total CF is 700, that's a walk in closet?


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## AZMDTed

My room is about 280cf. I think for chilling purposes your 5k AC unit is probably too small to have a quick cool down without condensing, and freezing, the humidity. Your dual solution is good idea for your set up.


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## stickman

Are you saying it had to run for 90 min to cool the room to 55? I agree with AZMDTed, you don't want the cycles to be that long. Depending on initial room temp, a 5k unit should run maybe 5 to 15min for your size room at 55F, if it is well insulated and sealed.


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## mainshipfred

Mine is much smaller 170 CF and I haven't had a problem and using the cheapest 5k I could fine. The humidity stays around 65-70. I agree your 5k may be too smal or faulty, but if your solution works just leave it.


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## we5inelgr

My coldbox is approximately 6.5' x 4.5' x 7' with a 6,150 BTU unit _(was a good deal)_. Definitely over sized. I'm sure insulation has a significant impact as well.

My A/C, even in the summer when it was 100+ in the garage, was only running for maybe 5 to 7 minutes to keep it cool at 65. Now, during Malo, i've got it set to 70F and the garage temp is around mids 80's...the A/C runs for less than 5 minutes now.


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## Flavad

Bembel said:


> *DIY Coolbot alternative*
> 
> If you connect an AC to a temp controller without contingency to control the ice build up on fins within a day your AC will be a block of solid ice
> 
> No need to hook your AC up to another temp controler, you can mimic the coolbot with two inkbirds / STC controllers connected in a series and a 5 volt light bulb and 5 volt power supply - 40$ at most
> 
> This is from a similar thread in HomeBrewTalk - I wish I had thought of this!
> 
> Makeshift Coolbot
> 
> It uses two STC-1000 units in series, as stated in a previous post, but instead of connecting the a/c unit, the STCs trigger a small 5v light bulb.
> I used two STC-1000 units, a 5v light bulb and a 5v power supply (old cell phone charger).
> First, I connected the +wire from the power supply to the light bulb. Then ran the -wire to the first STC COOL relay; from there it goes to the second STC's COOL relay in series, and finally to the other pole in the light bulb. Cover the light bulb with foil, attach the A/C unit's temp probe to this fixture and cover with foil again.
> Place the temp probe of either STC inside the A/C's evaporator fins, set the STC to 32. This will prevent the evap from freezing out. Use the other unit's probe as your room temp sensor, set it to whatever your target temp is.
> Set your A/C to the coldest setting.
> The idea is, just like with the coolbot, to trick the A/C into thinking the room is warmer than it really is, by heating the A/C's probe with the light bulb or whatever heater you want to use, while the STCs monitor both room and evaporator temperature and relay or cut power only to the light bulb. This way there's no need to mess with the A/C unit in any way, and you can use whatever A/C you want.
> 
> Good luck, when it comes to DIY projects involving fermenting, the beer nerds web sites are full of info!


I have a question with the wiring. On the STC cool relay do you run power to one side and the neutral to the other, or neutral on both sides of the relay? I know this is an old post but would appreciate any help for a newbie. Thanks


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