# Cool Room and fermentation Air Conditioning



## redcane (12/2/13)

So I scored an old garden shed made of 50mm Cool Room sandwich insulation panels, which I'm hoping to assemble into a fermentation chamber inside my shed. (It's an un-insulated tin shed so it's an oven in summer and too cold in winter. Before I scored the cool room panels I was planning to add insulation to the shed, but this seems easier).

Once it's together I'm hoping the temperatures will stay in the right range for brewing all by themselves, but was thinking I'd add an air conditioner to allow better temperature control if need be (and funds permit). The 'dead fridge' fermentation chamber I currently use needs ice blocks added to keep temps down in summer, so I'm hoping the insulated panels perform better.

I was doing a bit of basic research on the air conditioner, and it seems like some yeasts (or some beer styles) might be best fermented as low as 9 degrees, but I don't think that most air conditioners go that low. Anyone brewing beers at low temperatures using an Air conditioner (perhaps overridding the thermostat)? Or are they all brewing in a fridge? I think an Air conditioner is going to struggle to hit fridge temps, and a fridge isn't going to have the capacity for the cool room heat load. Commercial units are probably expensive. I'm ok with taking the cheaper option of a residential air conditioner and being limited to 16 degree minimum temps, unless anyone knows of another option?

Cheers all!


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## zindello (12/2/13)

Dare I ask, if you're going to spend the money on an air-conditioner, then why not just get a fridge to put inside your chamber?

That aside, If you build the chamber small, and go absolute overkill on the air conditioner you might get temps that low. Our air con in the bedroom is speced for a room twice it's size, and it frequently gets very chilly (sub 15 degrees) in the bedroom. If you buy the biggest air con that you can't-quite afford (split system) then you might get away with it.

That is one heck of an expensive way to ferment beer however ...


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## mkstalen (12/2/13)

Agree. Great you've got an insulated shed but I doubt it is going to seal well enough to maintain temps that low, and It'll cost you a fortune to maintain that low a temperature in that large a space in summer.

But you'll be better off spending money on a 2nd hand fridge than an A/C unit for the entire shed. Stick the fridge in the shed and ferment normally in it, the ambient temps inside your shed will be better which means the fridge won't need to run as much.


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## dougsbrew (12/2/13)

aircons arent designed to go that low and wont go that low. what youd need is a refridgeration unit.
they start around 2grand. your best option would be using a fridge(take the doors off and building a cool room off the front of it. 
dont go too big though or a second fridge will be required.


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## JDW81 (12/2/13)

I have to agree with the sentiments above. Rig of the 'cool room' and put a fridge inside it. Even a new fridge will cost you less than an a/c. Also will cost less to run.

I've got a bar fridge for fermenting in my garage and even on baking hot days it isn't' running excessively. 

JD


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## stux (12/2/13)

I've read that an in-wall a/c will work. You just hardwire it on then use an STC type controller to control it

Jamil Zainasheff got 5+ years out of 99$ jobbie

http://www.mrmalty.com/brewstuff.php


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## Beerisyummy (12/2/13)

Stux said:


> I've read that an in-wall a/c will work. You just hardwire it on then use an STC type controller to control it
> 
> Jamil Zainasheff got 5+ years out of 99$ jobbie
> 
> http://www.mrmalty.com/brewstuff.php


I just stumbled onto this thread while on my usual gleaning regime.

Great link.

I'm pretty sure an AC unit is much stronger than your average fridge boys and girls.


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## dougsbrew (12/2/13)

Stux said:


> I've read that an in-wall a/c will work. You just hardwire it on then use an STC type controller to control it
> 
> Jamil Zainasheff got 5+ years out of 99$ jobbie
> 
> http://www.mrmalty.com/brewstuff.php


im having trouble swallowing his stats..
on a 43degree day he reckons the aircon only ran for 30 minutes of the day..
i think he is fudging the figures.
it looks like it does work though..


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## Beerisyummy (12/2/13)

I believe it's human nature to fudge stats to suit an agenda. Even if the agenda is to show a cheapp way to do something.
Do you round up or round down. It's always upto you.

A piss poor window AC unit seems pretty similar to the commercial offerings installed inside some of my favourite coolrooms. Just way more residential.
If you insulated the room well enough and rarely opened the door it wouldn't be a stretch to hold low temps easily.


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## dougsbrew (12/2/13)

Beerisyummy said:


> I believe it's human nature to fudge stats to suit an agenda. Even if the agenda is to show a cheapp way to do something.
> Do you round up or round down. It's always upto you.
> 
> A piss poor window AC unit seems pretty similar to the commercial offerings installed inside some of my favourite coolrooms. Just way more residential.
> If you insulated the room well enough and rarely opened the door it wouldn't be a stretch to hold low temps easily.


so you have seen window ac in many coolrooms?? tell us more as i am interested in building a cold room..


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## Beerisyummy (12/2/13)

dougsbrew said:


> so you have seen window ac in many coolrooms?? tell us more as i am interested in building a cold room..


NO! No such thing in any of the commercial offerings I've seen over the years.
The ski ramp in Dubai is probably the closest thing.

As far as I know there is only only one type of commercial offering and it works the same as all the rest that use a compressor. This includes your bar fridge.
If designed right a coolroom should cope with a small compressor unit such as a cheap window mount jobby. AFAIK only the inbuilt thermostat will stop it from overshooting the prescribed ambient temperature. Beyond that a compressor will or won't be able to keep up with the heat input.


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## Online Brewing Supplies (12/2/13)

Got to be better than frozen milk containers ??
But not as good as a commercial cool room ??
Ye gets whats ye payes for, right ?
Arrr 
Nev


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## dougsbrew (12/2/13)

i found this linky - http://forums.whirlpool.net.au/archive/1936626
quite a few talk about the icing up being a problem.
and some even talk about the type of gas.
so i was thinking of making a cold room from 2 cheap bar fridges.
would i be better using a spiit or window jobby?


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## Beerisyummy (12/2/13)

I'll butt out now and let the fridgies chime in but a big draw card for any coolroom will be a strong fan inside the unit. This is also true for any decent AC unit or commercial refridgeration unit.
No point in the evaporator getting cold if you can't transfer the cold air. This is something ACs and commercial coolroom units do.


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## stux (12/2/13)

dougsbrew said:


> im having trouble swallowing his stats..
> on a 43degree day he reckons the aircon only ran for 30 minutes of the day..
> i think he is fudging the figures.
> it looks like it does work though..


He does use 4" of insulation


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## Ducatiboy stu (13/2/13)

Yes you can use an aircon unit. The trick is to try to get the shed/room airtight. In mine I had an old window rattler to cool the room. The room was app 3x5mtrs.
Basically i removed its internal thermostat and replaced it with an adjustable type mounted external from the unit. I could vary the temp easly, but it could only get to about 13*c then the unit would ice up and prevent cold air from blown out.
Newer aircon may be a bit more difficult to install externall thermostats due to the electronics.

You cant simple plug the aircon into a fridgemate unit either as it will only cool down to the aircons temp setting.


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## Airgead (13/2/13)

I have some similar plans...

I have an ancient window mount aircon that I have been saving for use in a coolroom. The plan is to have a small space (about 2mx1.5) insulated with 10cm rigid foam insulation on top of thick ceiling bats and a layer of reflective foil on all 6 sides. The aircon is sized for a large bedroom so it should be more than enough for a small space.Particularly with that much insulation. Once its down to temp it should hold pretty steady.

Should be an easy fit as its ancient enough that the lowest setting on the thermostat just means on all the time rather than any target temp. All I should need to do is turn it to ois fully on setting and plug it into a fridgemate.

I'll split the space in 2 with an insulated panel and a thermostatically controlled fan. One will be for kegs and be kept at serving temp. This will be the one where the aircon is fitted. The other will tap off cold air as needed to maintain it at about 14c for cool storage of wine/fruit/etc.

I may even get fancy and make two fermentation chambers off the side with thermostatically controlled fans to tap off enough cold air to keep them at fermentation temp.

Lagering I'll still do in my old chest freezer.

If the aircon doesn't work I might investigate a proper coolroom chiller. But the thing's lying there doing nothing so I might as well have a go.

Cheers
Dave


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## silvana (13/2/13)

This is something I came across awhile ago.

http://www.storeitcold.com/

Not the cheapest option. I would love a set up with this to cold store all my bottles and excess kegs.

No afiliation etc etc, never used one either


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## Feldon (13/2/13)

http://www.storeitcold.com/index.html


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## Airgead (13/2/13)

> If you have an old air conditioner without a Digital display, the
> CoolBot won't work for you. Almost all "Name brand" manufacturers have
> moved to digital controls by now. Frigidaire still has a couple
> knob-type models out there, but so far as we know, LG, Samsung and
> Toshiba and Kenmore have all upgraded by now


Bummer.The one I have is too old for digital displays. It has a knob and a switch.

Otherwise that looked like something worth looking at.


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## redcane (13/2/13)

I realise I didn't say in the original post that I'm normally brewing at 18-21 degrees, and so ordinarily not much cooling is required (might even be the average ambient temp). But if I'm spending any money I want to make sure I can brew any beer style I want.



zindello said:



> Dare I ask, if you're going to spend the money on an air-conditioner, then why not just get a fridge to put inside your chamber?
> 
> That aside, If you build the chamber small, and go absolute overkill on the air conditioner you might get temps that low. Our air con in the bedroom is speced for a room twice it's size, and it frequently gets very chilly (sub 15 degrees) in the bedroom. If you buy the biggest air con that you can't-quite afford (split system) then you might get away with it.
> 
> That is one heck of an expensive way to ferment beer however ...


Yep, maybe that is the way to go. However I can also see this adding heat load to the chamber, and as it's insulated the temperature in there will just climb. I guess there is always the option of a thermostatically controlled fan to blow hot air out during the night when it's colder outside the chamber. From my understanding it shouldn't be any more expensive than cooling an uninsulated room of the same size, it was more of a question of if the temperature can go low enough for some beer styles. I can live with 18 degrees, especially as I can use the space for other things (tin shed is currently way too hot), and cooling a smaller space further.



stienberg said:


> Agree. Great you've got an insulated shed but I doubt it is going to seal well enough to maintain temps that low, and It'll cost you a fortune to maintain that low a temperature in that large a space in summer.
> 
> But you'll be better off spending money on a 2nd hand fridge than an A/C unit for the entire shed. Stick the fridge in the shed and ferment normally in it, the ambient temps inside your shed will be better which means the fridge won't need to run as much.


I'm pretty sure it's almost air tight (was sealed with silastic) except the door. With little effort I could probably make that seal too. I've calculated the heat load for 50mm panels to be between 350-700 watts with a temperature differential of 25 degrees across the chamber walls (assuming it's sealed). Pretty sure the high COP of some air conditioning units compared to residential fridges might make up for the increased space, especially as fridges are designed to go to a much lower temperature than I normally need. However the reduced running time when running at higher temps does help.



Beerisyummy said:


> I just stumbled onto this thread while on my usual gleaning regime.
> 
> Great link.
> 
> I'm pretty sure an AC unit is much stronger than your average fridge boys and girls.


From my research a residential fridge compressor is only made to move 60-180 watts of heat - small surface area means that this is generally the most heat that will transfer in. Whereas AC units are made to move 1kW to 18kW but with a smaller temperature differential. I suppose that is why the commercial cool room stuff is expensive - it has a high heat capacity of AC unit, with the larger temperature differential of a fridge.

Maybe a fridgie knows if the extra efficiency of running a fridge in an 18 degree chamber (versus up to 48 degree tin shed temps) outweighs the added heat load on the AC cooling the chamber?


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## redcane (13/2/13)

Feldon said:


> http://www.storeitcold.com/index.html


I'm a little sceptical of their claims - "patent pending technology that just became available in 2006".... But in theory the coils in a split system go much lower than the target room temperature. I can see the efficiency suffering (and heat capacity needing to be de-rated) but that is probably ok if I only want to do a lager once in a blue moon!

Also they recommend 4" of styrofoam - which is a bit more than I have.


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## mikec (13/2/13)

redcane said:


> Also they recommend 4" of styrofoam - which is a bit more than I have.


Build twice as thick, half as big.


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## Camo6 (13/2/13)

Funny how relevant threads seem to pop up at the right time. Just picked up a trailer load of coolroom panelling which I plan to use to insulate my current brewshed. Initially I just want to insulate it from the sun but would like to eventually convert it to a walk in coolroom. Was planning on using an old a/c wall unit for the job (hooked up to an STC1000) so will be watching this thread closely.


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## redcane (13/2/13)

mikec said:


> Build twice as thick, half as big.


Good point!

I was considering I could put my dead fridge inside and it'd be more insulation. And I could disassemble the panels and reassemble them for a smaller space, but it's currently a very nice jigsaw puzzle


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## booargy (13/2/13)

I need a glycol chiller. So I was working with the aircon blokes. They reckon that an air con unit is best value. if you are getting icing the unit is to small.


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## redcane (14/2/13)

There is a bit of a discussion about store it cold here: http://forums.whirlpool.net.au/archive/1936626

Basically it looks like there are some features designed into the commercial cool room units that residential a/c will lack, but the coolbot tries to compensate for. There are some concerns around humidity which probably aren't an issue with brewing.


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## dougsbrew (14/2/13)

Maybe a fridgie knows if the extra efficiency of running a fridge in an 18 degree chamber (versus up to 48 degree tin shed temps) outweighs the added heat load on the AC cooling the chamber?

tough question, all of the heat that the fridge makes will have to be removed by the aircon + keeping the room cool aswell, you be running 2 cooling units so i imagine would be less efficent whereas a fridge in open air dissapates without any other power drain.
i do like this idea though.. you could have your lagers in the fridge, and your ales in your 20 degree room, and in winter the heat from fridge would warm the room.


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## redcane (14/2/13)

That would help in winter - but I've always found a heat mat a cheap enough and easy option. It's always been cooling that I've had issues with.

I also considered the idea of placing the fridge through the cool room wall - so that the rear coils vent outside the coolroom. The fridge might not run as efficiently (higher ambient temp) but should get less heat transferred into it. I guess you could put a fridge sized door in, and during winter move the fridge inside the cool room and close the door.

I wish I had the cool room set up for the heat wave in January so I could have measured what sort of temperatures it maintained without active cooling/heating.


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## wobbly (21/2/13)

Check out this site http://franklinbrew.org/members/sj/walkin.html on a complete cold room build

and another one here http://www.homebrewtalk.com/wiki/index.php/Walk-in_Cooler

Cheers

Wobbly


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## justsomeguy (7/3/13)

Took me ages to find this thread again. :blink:

Anyway, I've built a 'coolroom' using 75mm coolroom panels and a small AC unit. It holds 12 kegs easily and has a separate section independently temperature controlled for up to two fermenters.

The system works a treat and has for the past 3 years or so. I run the system at around 4c whilst the fermentation section runs at anything from 6-20+ depending on whats fermenting. I've bypassed the thermostat and just run a digital controller. The cooler hasn't skipped a beat even during days when the temperature in the shed (where the cooler is) has been well over 50c. During winter in WA (not that cold) the AC unit runs for around 10 minutes every two hours or so. During summer it might be 10-15 minutes every hour. When I first turned the system on 3 years ago I also hooked up a power meter to see what the usage would be like. Over that first week the power consumed worked out to be around $35 per year in running costs. Obviously power costs have risen since then and I've not done another test of the systems efficiency.

In all the time the system has been running the only issue has been that it has iced up 3-4 times. The times its iced up were during very humid periods when we were opening the door a lot which obviously lets a lot of warm moist air into the cooler. I've found that once the cooler has removed the water from air inside the chamber that there is very little chance of ice forming, and mould, and other such nasties.

The most important thing I've found is to make sure that you lower the temperature of the system slowly over a couple of hours if you have it turned off for a while. This allows the cooler to remove the moisture from the air without everything freezing up.

There was a thread about my system complete with pics somewhere on this site but I can't find it right now.

Regards,
garyd


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## Yob (7/3/13)

Photos please... Lots of photo's


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## booargy (7/3/13)

here it is Frankencooler
http://aussiehomebrewer.com/topic/46207-frankencooler/


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## redcane (7/3/13)

Awesome - looks way better finished than mine. I've just been spraying expanding foam into the gaps, and I don't have the overlap on the door. I think I'll definitely have to add mechanical cooling to mine eventually, but with the heatwave over it's sitting at good temperatures as it is!


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## justsomeguy (8/3/13)

booargy said:


> here it is Frankencooler
> http://aussiehomebrewer.com/topic/46207-frankencooler/


Yep, thats the one !

I wrote the damn thing then couldn't find it. :blink:

Thaven't really had any issues with it and SWMBO reckons it great when we have parties as there is sometimes enough room to store the overflow of food in there as well.

Regards,
jsg


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## redcane (20/3/13)

So my cool room is mostly sealed, aside from a gap above the door. The brewing temps are pretty good for not having any active cooling, but the weather also isn't as hot as it was. The fermenters are staying about 6-8 degrees under the peak temperature in the shed, which is certainly a good help but won't quite cut it in the middle of summer. I think I'll have to sit them in a water bath with ice blocks, or get a fridge or air conditioner for next summer. We'll also see how the temps go in colder weather, I'm hoping the heat mats don't have to work too hard, and I've got a sparky coming to put a power point and light fitting into the cool room.

Last steps are to put a strip of styrofoam across the top of the door to block that gap and get some rubber strips to seal around the door when it closes.


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## Sterlo (21/3/13)

many sleepless nights i have had dreaming of temp controlled rooms, ale rooms, lager rooms, conditioning rooms.....ahhhhh

Sterlo


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## redcane (2/11/13)

Well I've now picked up a small cooling only window/wall mount air conditioner. I think I can get it through the cool room and shed wall, so it transfers heat from the cool room outside the shed. This should avoid further heating the oven that is the shed in summer, as well as being easier on the unit (it's condensor is in the cooler air outside the shed).


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## wide eyed and legless (2/11/13)

I went down the same path as you redcane didn't have any cool room panels though, just got some poly insulation fitted it and lined the inside of the shed with pine lining board had a fridge in there during winter and the heat generated by the compressor kept it at around 15-16 C. 
Now I have just bought a reverse cycle split a/c from Masters only $695 and after having a look around they were the cheapest I could find, just got to wait for my brother to come and install it.
The good thing about the reverse cycle I will be able to keep a temp of 18 C during winter and it wont be much more power usage if I put the fridge back in over next winter.


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## Beermoose (6/1/14)

So I just made this work and wanted to share my tricks.

I wanted one area to keep my beer cold and to ferment,

There are two major problems. First is the inability of a window unit to go below 60f. Second is the propensity for a window unit to freeze up...

First, strip out the stock thermostat. 
Next, install a line control external thermostat in its place. Locate the thermoprobe between the fins of the evaporator coil, toward the bottom of the unit. This will give you the ability to kill the compressor at 32f and prevent freeze up.

Second, using a second thermostat, place the thermoprobe in the area to be cooled. Plug the window unit into this thermostat. 

As we are preventing the unit evaporator from going below 32F, the room will never get to 32F. But good beer should never be served this cold anyway. 

Set thermostat number one at 32F - freeze up is now impossible! Also, capacity of unit is now restricted. You may need to use a larger unit in a shed.
Set thermostat two at target temp above 40F

Now, purchase a 20 gallon ice bucket.
Place carboy in the ice bucket 
Install a 75 watt Eheim Jäger aquarium tank heater in the bucket.
Transfer cooled wort to carboy 
Fill bucket with sterile solution until carboy is light, but not floating.
Set Jäger at desired fermentation temp. 65 to ?..F
To go below 65, you will need to use an external thermostat.
For diacetyl rest, raise temp on heater.


You can have several buckets at different temps!

Finally, you can place all your finished brew in the shed and keep at serving temp.

Brew,
ferment,
Chill
Drink
Repeat!!!

If I liked people as much as I like beer, I would never have time to brew!


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## wide eyed and legless (6/1/14)

I finished my cool room using the split a/c even kept the fridge in there the lowest setting is 17 C but found it went down to 15 C so I have mine set at 19 C and it keeps the room at 17 C and a weight off my mind.


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## Greg.L (6/1/14)

I have worked at a place with split a/c for a coolroom (for winemaking). Works well because the heat is pumped outside by the compressor. Much cheaper to install than cooling for individual tanks. If you put a fridge in an airtight insulated room it defeats the purpose because the heat is still being contained inside the room - you need to get the heat out of the room. I live in a place with cool nightime (below 10c often even in summer) temps and have thought of a vent fan with a timer to pump cool air inside at night when the temperature drops. My cellar is well insulated but no electricity nearby so I would need a solar battery setup.


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## wide eyed and legless (6/1/14)

My initial intention Greg was to take the fridge out, because before I got the split a/c in the fridge would push the temperature up, but because the room is now at a lower temperature the fridge on -off cycle is a lot less so I am not getting any noticeable heat from the fridge compressor.
Aside from that I couldn't be bothered moving it out as I would have been moving it back in for the winter as a source of heat. 

I have thought of buying a solar set up for my greenhouse hydroponics, I have seen them with a 12 AH battery for $200 inc controller and solar panel on Aliexpress free delivery.


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## mrsupraboy (12/1/14)

to anyone thinking of getting an air conditioning unit for under 21'c. you would be lucky for it to hit 21'c with out the ac icing up. most Ac's aren't designed for under 21'c. you would be better of getting an old bucket freezer/fridge and changing the thermostat in it..
believe me its my trade. and for the air conditioner to get there if it did . the amount of electricity you would use is for nominal. and getting a bigger air conditioner may get it there faster but still more electricty


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## Feldon (12/1/14)

Mrsupraboy (and others), can you comment on the claims made by CoolBot (here http://www.storeitcold.com/index.html ) which I posted in the first page of this thread (see the FAQ page in particular). 

Seems these guys have done it with much less energy consumption and using an air-con.


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## mrsupraboy (12/1/14)

haha putting a management system on an ac is pointless. it will just change the external deadband in the thermostat to stop start up on the compressor as much so instead of operating at 1'c it would be more. but obviously regardless of system fridge, air conditioner, freezer. the area you are trying to cool is gonna be what costs you the most electricity and how well its insulated. the difference between an air con, fridge and freezer are the designed temps they are designed to work on e.g. a/c is 20 to 24'c, fridge 20'c to 1'c and freezer 2'c to -22'c.


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## Ducatiboy stu (12/1/14)

They way I see it as working is that it cuts the compressor just as it ices up. If you put a thermometer in the output, it will measure about 12-13*c normally. 

Its the icing up that stops the unit cooling. So if you can stop it ftom icing up it can continue to cool.

Note that it requires a fairly well sealed room that doesnt goet open and closed often.

Its pretty much a 2 probe STC.


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## mrsupraboy (12/1/14)

the problem with that is, is that the compressor uses 10x power on start up so it would be using more power not less


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## Ducatiboy stu (12/1/14)

The other thing they say is to buy a bigger unit than required. I suppose they are working on the idea that a bigger unit doesnt have to work as hard.


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## wide eyed and legless (12/1/14)

I have a split a/c which as I said in an earlier post the temp goes down to 15 Celsius when set at 17 Celsius (the lowest setting) which it can maintain on a 50 degree day I haven't put it in a sleep mode and it runs constantly day and night the compressor kicks in when it needs.
What sort of A/C are you talking about Mr Superboy?


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## MastersBrewery (12/1/14)

the other thing I've seen is extra/external fans blowing air back on to the cooling fins controlled by stc to stop icing up, this apparently works well. The cost of using any cooling system really has 3 factors, one being the insulation, the next external ambient temp and the third being amount of ballast at set temp. If you have 2000L at say 5c with insulation and moderate active cooling, it really isn't going to move to quickly in either direction.


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## Greg.L (14/1/14)

I don't understand the claims about icing up at 21c. The compressor is outside the room on a split system. My compressor for my house ices up outside in winter when I use it to heat, the temperature outside might be -2 below but the unit runs for a couple of hours before it ices up, then it de-ices itself by running in reverse for a few minutes. When using split a/c to cool, obviously it is the fan inside that runs cool, mine drips a lot but I have never seen ice form. If it did form ice it would still be cooling down the coolroom because the hot side is the compressor outside, having ice inside a coolroom would still be cooling it down. As far as I know the theory about drawing huge amounts of power at startup is just an urban myth, I have asked several professionals about this and it doesn't seem to be true. A/C units the days run on DC from inverters so they are pretty efficient for power use.
I still can't see the point of putting a fridge in a coolroom, it seems a bit like leaving the fridge door open down to cool down your house, might work for Homer Simpson but not much good for the rest of us.


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## Ducatiboy stu (14/1/14)

Couple of points Greg.

Most units have a sensor to stop it icing up.

If it ices up it will no longer cool because the head unit cools by drawing air thru the cooling fins. Once they are blocked by ice ( or dust ) it can no longer draw cold air. 

The amount of ice in the head unit will cause no coolong effect. It wouldbe like puting a bag of ice from the servo in your coolroom and expecting it to cool it down.

Your outside unit will ice up normally when in heating mode. Thats why they are called revers cycle. You will notice in summer that the outside unit will blow hot air. 

21*c more reffers to the temp a unit will maintain and cool for a given room size. The head unit usually blows air out at about 13*c. The smaller the room the lower it can cool & maintain the temp. Keep in mind that the cooler the room the greater the chance the head unit will ice up as it drawers colder air throught the cooling fans. 

A reverse cycle air-con is a heat pump. It moves heat from inside to outside by sucking the warm internal air thru the cooling fins in the head unit.


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## MastersBrewery (14/1/14)

Air conditioners being used for cool room use have been well documented on our American cousin's site, including fixes for icing issues. I'm not going to say do a search, but there is plenty of info out there from other HBers who have successfully implemented such a system, all the way down to fridge temps.

MB


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## Greg.L (14/1/14)

Ducatiboy stu said:


> Your outside unit will ice up normally when in heating mode. Thats why they are called revers cycle. You will notice in summer that the outside unit will blow hot air.


It depends a lot what unit you use. My unit is a fujitsu, it only ices up when the outside temp is very low, below 2C. Other cheaper units will ice up much more quickly. I agree that an iced up unit will not work very well for cooling, but the ice should melt and the unit restart. The humidity will affect how well they work, if you send the drip water outside the coolroom should stay pretty dry, but in the tropics the humidity may cause problems. I don't know how low you can go with a decent split a/c but I think it should be well below 21C. They don't ice up instantly, it takes a while, but of course it will depend on the unit you choose how well they cool. There are some pretty crappy units around, like anything you need to choose the right unit for what you are doing.


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## Ducatiboy stu (14/1/14)

MastersBrewery said:


> Air conditioners being used for cool room use have been well documented on our American cousin's site, including fixes for icing issues. I'm not going to say do a search, but there is plenty of info out there from other HBers who have successfully implemented such a system, all the way down to fridge temps.
> 
> MB


True, but it will only get a cold as what the head unit pushes out. And not a lot push air out at 4*c.


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## mrsupraboy (14/1/14)

It all comes down to design. Acs are not designed to run at them temps. Yes u can put a De-ice stat on the evaporator. But Acs are not designed to run at that temp lower than 20'c. At 410kpa there running at 2'c temp. Acs are pressure temp related. Meaning a drop in pressure is a drop in temp. Delivering about a 10'c temp difference over the coil. Once the temps drop so does the pressure. Resulting in icing up. Fridges and freezers run on different gas enabling them to operate at lower temps. Yes u may get one to work after a lot of stuffing around. But not as easy as just putting a new smart controller on it.


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## redcane (14/1/14)

wide eyed and legless said:


> I finished my cool room using the split a/c even kept the fridge in there the lowest setting is 17 C but found it went down to 15 C so I have mine set at 19 C and it keeps the room at 17 C and a weight off my mind.


Good stuff! I got mine working with a second hand box unit a/c, but the fan failed after a month or so. I now have a Kelvinator KWH15CMC, and it's much quieter with less vibration. It's only got analogue controls, and on it's lowest setting the cool room gets down to 15°c.



wide eyed and legless said:


> Aside from that I couldn't be bothered moving it out as I would have been moving it back in for the winter as a source of heat.





Greg.L said:


> I still can't see the point of putting a fridge in a coolroom, it seems a bit like leaving the fridge door open down to cool down your house, might work for Homer Simpson but not much good for the rest of us.


See the above Greg - in winter when the ambient temp is too low and the cool room gets too cold, a cooling only air conditioner can't heat it back up. The fridge compressor generates some heat, hopefully enough to keep the temperature where the a/c is set. Yes you could just run a heater, but if you were running the fridge outside the cool room anyway you can use the waste heat this way.

Additionally the fridge can more easily vent heat in the cool room in summer so it shouldn't work as hard and less heat should transfer back in. Yes it makes the cool room cooling unit work harder as a trade off.

My future plan is to put a small freezer unit inside the cool room to put my serving kegs in with taps out through the side of the cool room. Basically I'd have a small chamber about one keg deep at ~4°c along one wall, which would also form a small bench when not swapping kegs, and the rest of the cool room would run at fermenting temps. If I was really tricky I'd set it up so it can vent heat outside the cool room in summer, and open vents within the cool room in winter to keep it at fermenting temp.


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## Greg.L (14/1/14)

Vents are the way to go if you live in a cool area and want to save money. I have looked in the past for 12 or 24v dc vent fans but couldn't find any. (if anyone knows where to get one let me know) .If you have power connected you can put in an ordinary ac vent fan plus an inlet to let cool air in, with a timer so it only comes on a few hrs in the early morning. Fairly cheap and easy to install.


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## wide eyed and legless (14/1/14)

Have a look on Alibaba Greg, although they deal in quantity they often will send out a sample at your cost.


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## booargy (14/1/14)

Greg.L said:


> Vents are the way to go if you live in a cool area and want to save money. I have looked in the past for 12 or 24v dc vent fans but couldn't find any. (if anyone knows where to get one let me know) .If you have power connected you can put in an ordinary ac vent fan plus an inlet to let cool air in, with a timer so it only comes on a few hrs in the early morning. Fairly cheap and easy to install.


http://www.rpc.com.au/catalog/advanced_search_result.php?keywords=fan&submit2=Go


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## mrsupraboy (14/1/14)

your better of hooking the vents to an external sensor so they open when then temp is down at a certain level. also use an toilet exuast fan and turn it around so air comes in and set that to an external sensor so it turns on when needed to. a great way to save electricity.

note most toilet exausts fans have dampners so they will open on when on.

you could really use the stc1000 if you wanted.


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## Ducatiboy stu (14/1/14)

The ducted air vent/extractor units now use in bathrooms to vent are great for sucking hot air from an internal fridge.

The trick is to remove as much warm/hot air as possible. 

If you can remove the warm air from behind your fridge, the better and more eff it will run.


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## wide eyed and legless (29/5/18)

Anyone thinking of making a fermenting room / shed I have 2 split system inverter air cons one is a 2.6 Kw cooling 2.8 Kw heating the other maybe a bit to big is a 5.3 Kw cooling 5.7 Kw heating both about 2 years old and both are Midea $200 and $400 respectively. 
This is my set up runs 24, 7 all year.


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## wide eyed and legless (29/5/18)

2.7 Kw unit sold.


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