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My wine store needs cooling. It's smoothing out temperature fluctuations, but it's getting to hot during heat waves.
Id like something based around 12v DC so that I can use solar/SLA battery, although 240v is possible.
What approach would you take?
The store is an insulated "box" of about 2m3. The walls are foil backed 40mm polyurethane foam panels (like Celotex/kingspan) so really easy to cut/drill for ducting or pipework.
Im not sure a [url= http://en.wikipedia.org/wiki/Thermoelectric_effect ]Peltier device approach[/url] is going to be sufficient, so am looking at compressor/condenser approach.
Would an old fridge be usable for parts? or car air conditioning unit? or perhaps a dehumidifier (I have one sitting idle)
bodgers, I need you.
Here's the problem:
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I'd have thought the guts of an old fridge would be your best option - that is after all designed to do a job much like the one you're trying to do. No experience in bodging fridges though, and one thing that springs to mind is the presence of dodgy chemicals.
Though I'm mainly just ticking - intrigued to see suggestions from the real bodge merchants.
Be very careful messing about with chiller compressors - toxic fumes and pressurised gases.
SPeaking ap a bodging expert my answer would be yes
Stick an old freezer down there, leave the door open.
Main problem would be taking the gubbins of a fridge & fitting it into your space without having to re-do all the pipework & stuff (which would mean dealing with all the refrigerant & stuff).
Peltier would work but you'd need a meaty one for that size & they are very power hungry.
Just wondering if you could get some car a/c parts from a scrappy, plumb it all in & get a garage to recharge it. Is the equipment they use mobile or not?
Something like these people:
http://www.coolcaraircon.co.uk/
Not cheap though using car parts I wouldn't have thought, bearing in mind a new compressor for my air con was about £400.
eBay prices for car compressors and condensers was pretty much ruling it out.
Is fridge coolant pressurised then?
If I could tear open an old ridge and extract the condenser/compressor and pipework in one, I reckon I could fit it either side of the panel (cold side/hot side)
A couple of elements out of electric cool boxes fastened into the top?
One of these?
http://www.bhsdirect.co.uk/BH_Amcor_AirCon_Air_Conditioners_40037789/version.asp?refsource=BHfroogle
A couple of elements out of electric cool boxes fastened into the top?
not cheap...and Id need quite a few....
Is fridge coolant pressurised then?
What do you think "compressor" means? 🙄
aracer:
Thermostat Range - 18-32*c
and
Power Consumption - 890W
Id need 14degC. Id probably want to control it with a basic switch though. so could bodge an external one...
What do you think "compressor" means?
haha.
Is it under pressure when the compressor isnt on though?
Compressor?
I 'ardly know 'er!
Radiator fitted into the back of the wine store plumbed into a pumped circuit which passes through an old fridge located at the side of the store. Controlled by a stat, natch.
Well you said you wanted bodged! There is the potential to neaten it up by using a small 3-way caravan fridge.
http://www.ebay.co.uk/itm/Electrolux-RA122F-Fridge-240v-Caravan-Tent-Awning-/300590634034
Originally I was going to install some spare underfloor heating pipe around the inside of the store, and then use a bilge pump to pump water from a rainwater harvest storage tank in the ground around the pipe.....
...but in the end I didnt bother with the rainwater storage tank, so I have no heat sink, otherwise, thats what Id still do.
Or how about cutting a fridge shaped hold in the side and mounting a fridge in it - don't forget to leave the door open!
so I have no heat sink
The underfloor circuit in the rest of the house?
Or how about cutting a fridge shaped hold in the side and mounting a fridge in it - don't forget to leave the door open
thats closer to where my brains going...
The underfloor circuit in the rest of the house?
no realistic way of connecting to it, and if air temp in summer is 20degs in the house its not going to help.
Underground water should remain around 11-15degrees all year.
There are of course more traditional methods
http://en.wikipedia.org/wiki/Icehouse_(building)
got snow?
Ok, so how about digging a trench outside somewhere. Below a metre, the temp remains constant at 7 degrees (ish). Sink a coil and pump through that?
Ok, so how about digging a trench outside somewhere. Below a metre,
No. because Im lazy.
Id imagine also unless its quite a big hole, energy being pumped into the sink may be arriving faster than it can dissipate in the ground.
got snow?
I'm guessing you have a freezer to generate ice packs.
Fridge gas isn't toxic. The ozone layer doesn't like it very much though.
I don't think you'll get something based around a 12V supply.
14degC SP is out of the range of a split system too. I don't think you'd have a lot of joy with the guts of an old fridge either, I reckon you're looking at about 1kW of cooling and you will probably have problems with the evap coil icing up. Not an easy one TBH.
Perhaps evaporative cooling (adiabatic)? Water supply on a float valve, basic stat operating the fan?
75 ft of 6" pipe laid out at a 2m depth in the garden. Small stack at the other end, small 12 or 24V fan drawing air along pipe. Cools air to approx 55 deg F and pushes it in to your storage area. Can be run mains or from a single solar panel.
is that proven tech that tootall? got any links?
Stoner
Skimmed the thread and will give it some thought but FYI pressure on the 'high pressure' side of a heat pump/fridge can be 16-20 Bar from memory depending on the refrigerant used. Take care with any 'bodging'!
75 ft of 6" pipe laid out at a 2m depth in the garden. Small stack at the other end, small 12 or 24V fan drawing air along pipe. Cools air to approx 55 deg F and pushes it in to your storage area. Can be run mains or from a single solar panel.
Won't that dry it out? Iirc you want cOnstant humidty too?
I think you're looking at the problem the wrong way around.
You need more thermal mass not refrigeration. Unfortunately your shed is a lightweight structure so heats up quickly for a given heat input (like sunshine on the roof).
Wine cellars are normally underground and have lots of exposed stone/earth so have a very high thermal mass or thermal inertia.
Increasing the thermal of the shed walls might be more effective.... lots of flagstones or breeze blocks on the inside of the insulation might do the trick
The shed is insulated wonny.
The store is a second layer of insulation.
How about a water cooler and a water circuit inside the store.
http://www.ebay.co.uk/itm/Blue-Grey-Premier-Water-Cooler-37cm-x-31cm-x-111cm-/110732345672
Just need a small lemonade bottle header, a 12v inline pump, and a relay switch to turn the water cooler on at the same time as the pump.
http://www.solarproject.co.uk/page2.html
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He maybe right. There is a reason why wine is often kept in caves and cellars. Ours stays cool whatever the weather just 1-2m below ground level in a stone cellar.
What about heading down?
like too talls idea but as wonny notes the issue is the shed overheating.
Can you surround the wine rack with heavy stone as a thermal sink and then close it off , from the rest of the shed somehow? like an old fashioned larder?
Perhaps wet it on the outside so evaporation will further cool it?
Can you not just dig a hole in the floor and build a cellar underneath?
stone inside the shed wont really help as it will just add to temperature buffering not cooling. The cellar heat sink thing is being underground where ground temp is always low and acts as a permanently regenerating heat sink.
Im trying to avoid digging more holes, so electrical cooling is the preferred solution at the moment. Adding thermal mass inside the insulated envelope and cooling that would help.
Just put it in Scotland and it will remain cool all year round.
Is it a cellar kind of arrangement (wine open to the atmosphere) or does the wine store cabinet have a door on it ?
My understanding is that Refrigeration systems are designed in terms of compressor size v's refrigerant = temp output. Bodging something up would compromise any efficiency and cooling effects, though saying that over engineering would be the way forward, for example 2 x compressors and increasing the path of refrigerant. Or putting in a large ish fridge unit.
A small chiller unit would be ideal if you can live with 220 / 240v
Smudger your right about the pressures when running, but even when static the pressure in the system evens out about 5 bar assuming R134a refrigerant A lot higher if 404 but that would be over kill. I trialed a Penguin refrigeration unit that would have done the job a couple of years ago. Basicaly it was a 12 volt scroll compressor and small condensing set with fan mounted on a plate then piped to what can only be described as a thin radiator to which we blew a fan across to distribute the cooling. We found it very efficient and low consumption.
geoffj's solution is probably the best bodge mentioned so far. A very large barrel of rainwater might even do the job as a heat sink rather than having it pass through an electric fridge.
Put a zigzag of pipework behind your wine store. Copper would be best, but the stuff you get for solar thermal heating doesn't look like copper, so whatever that stuff is would probably work well enough. Run this through a pump (not much power required) and into a large coil of pipe dropped into a big rainwater barrel kept in a shady place. if you can partially bury it, even better.
Ideally, stick some basic controls on the pump so that it only operates during the day, or for 10 minutes every hour, or whenever the temperature gets too high.
A really bodgy bodge might just be to have the aforementioned big rainwater barrel, drop a submersible pump into it, run water through a coil behind your wine, then drop it back into the barrel. This would definitely have to be run on some kind of timer or thermostat.
Might work, might not. Don't know if a rainwater barrel would have enough thermal mass. Insulate the barrel as much as possible.
EDIT: I'd suggest that bodging it from an old fridge is a non-starter. Getting hold of the extra coolant required is probably going to be a pain and you'd have to massively extend everything so that the heat could be dumped outside. Otherwise, it would be equivalent to having a fridge with an open door, which over time just makes the whole room warmer, az any ful kno.
Stoner, my dad was a refridgeration engineer, so I grew up with it.
The ideal thing would be the kit out of an old commercial fridge freezer as they are configured for blown air.
The pressure in a fridge/freezer is NOT dangerous. I have seen hundreds of systems punctured and pipes cut off systems and its no worse than letting down a road bike tyre (or Fox Shock!).
Compressors have a fill pipe. This is normally braized close at the factory, so if you want to refil then you firstly have to fit a fill valve.
The heat exchanger on the back of the fridge is low pressure and is relatively easy on most to take off, braize on extensions and relocate.
Most donor fridge freezers have the internal heat exchanger (the bit that gets cold) integral to the shell of the cabinet, so you might struggle to find an internal heat exchanger.
Hope this helps!
IF it was me then I would buy a 300 quid air conditioning unit instead.
Oh and not sure what gasses are used these days (20 years since my dad did it). Used to be Freon, that was not dangerous (except for Ozone!)unless it went near a naked flame. The combustion product is phosgene gas, not nice stuff.
Wonder how much of the ozone hole was my dads fault.
cheers CHB. That all sounds wonderfully complicated, so Im tending to the pumped water circuit as fridge circuits sound a hassle.
So do we think a jacket wrapped water butt full of water with a coil of underfloor heating pipe (got loads left over) through it and then via a 12v pump and zigazagged down the back of the box might do it?
just need a thermostat and timer controller.
Most of the gases these days arent ozone depleting CHB I remember freon and guys messing with it while brazing for a laugh 😯 I have also seen engineers cracking bottles of refrigerant off and directing it on to cans of coke to chill them down before drinking in summer. The water method seems to favourite I think you may need to wrap the coil quite close and round the sides as well to make it as efficient as possible and a small amount of air circulation wouldn't do any harm.
Basically Stoner, you are building a big fat wonderfully Heath Robinson version of this:
http://techgage.com/article/zalman_reserator_1_v2_and_fan_kit/
Can we all pop round for a glass of Chateau Latour?
If I had the time, the inclination, or the ability to recall 10-year-old engineering classes, I would do the sums for you... I may get bored enough at some point, but I'm sure someone who's more up-to-date than me will get there first!
I shall start collecting the bits I need then
No Latour, but a few nice Savennieres.
Cheers for all the help guys.
As an addition, you could increase the thermal mass of the store iteself, by putting a [i]pond[/i] in below the wine racking - say a foot deep?
Reminds of some trouble they had at Edinburgh Botanic Gardens when they drained one of the ponds inside one of the glass houses. They couldn't get the temp regulation right for ages afterwards 😐 - dopey gets!
Chb is talking about the R12 gas which was fun when brazing! Also the only gasses which are non ozone depleting are ammonia and propane, the rest are subject to the f-gas regulations.
Basically, you will get some cooling effect from what youre trying i dont think that you'll be able to hit 14degC with it though. Assuming ground temp of 12degC and a rough deltaT of 6K, you'll be looking at 18degC IF the system is sized correctly. I reckon that, at the flow rates you'll get off small pump and the thermodynamic qualities of water that the indoor coil you'll need would be huge particularly without a fan.
If you do bastardise a fridge, you'll need a line tap valve for the compressor stub, a turbo torch, some gas, manifold gauges and preferably some oxygen free nitrogen, a vacuum pump; it goes on.
Stoner - a lot of Passivhaus air systems are based on air intake heat exchangers:
[url]= http://www.passivhaustech.com/archive/wordpress/04/2011/air-intake-ground-source-heat-exchanger [/url]
[url= http://www.builditsolar.com/Projects/Cooling/passive_cooling.htm ]Useful passive cooling info[/url]
I was in a shelter in the Mojave Desert last week - 118F air temp outside. There were 3 double ducts about 40' long feeding into a box in the corner that was running a 4A 24V solar-powered fan. Air temp inside was about 78-80F and this was only achieved through air-ground heat exchanging in the ducts. It has been working like that for 18 months!
That second link has evaporative cooling as mentioned in my earlier post, which is the manner in which tootalls original idea works also.
Stoner, as you've already found out you can insulate all you like and the space will still heat up if it's an enclosed space. You need more thermal mass like exposed stone, concrete or brick, (high density materilas) . A big barrel of water will help in that way as well.
thanks for all the links etc.
will read up and come up with a feasible design based on the space, layout and resources I have.
EDIT: BTW wonny, the slab in there is about 6-12" thick concrete (uninsulated) about 150sq ft. Its a massive bit of thermal mass.
It was made with the (larger than expected!) balance load from a floor slab fill for the barn
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My original suggestion isn't evporative cooling - it is using the duct in the ground as a heat exchanger.
If you're blowing air over water, the water will evaporate and provide cooling ( providing the rh isn't too high). That's evaporative cooling.
wrecker - I can't see that I mentioned water once. I mention pipes, fan and air. I know what evaporative cooling is thank you very much.
I would have thought that the most obvious solution is to have a temperature alarm 'thingy', and when the temp is too high, it auto-posts on STW annoucing a party at Casa Stoner? The reduced number of full bottles in the store will help the other bottles calm down a bit.
I'm a simpleton, but... Could you replace the racking with something with more thermal mass? A 'shelf' of stone or slate every few rows?