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Building a passivly refrigerated out house

Posted: Sat Jan 24, 2015 6:04 pm
by doofaloofa
As part of our up coming house extension tha pantry (a cold out house conected to the main house), is being rebuilt

I plan to rebuild it to employ some form of passive refrigeration to keep the temperature low in the summer to act as a walk in fridge/meat locker

It is on the north side of the house, and will involve an insulated roof, but the part I'd like to discuss is the north wall of the structure

A South African friend told me in the Bush an old method of keeping a house cool was to build cavity walls, filled with coal. Water was dripped on the coal, wich evaporated rapidly due to the high surface area of the slightly porus coal

What do ya'll think about that?

Re: Building a passivly refrigerated out house

Posted: Sat Jan 24, 2015 6:38 pm
by Marc
I guess it's worth a try, but I can't see there being a large amount of evaporation from between the walls - in our(your?) climate, air to moist most of the time.

Re: Building a passivly refrigerated out house

Posted: Sat Jan 24, 2015 7:29 pm
by Odsox
The Victorian way to keep the big kitchen larder cold was to build it over a well, which is probably inspired by the even older habit of building dairies over running streams.
Probably no use to you though Doofa unless you're thinking of sinking a borehole.

Re: Building a passivly refrigerated out house

Posted: Sat Jan 24, 2015 7:33 pm
by ina
That's my experience, too. Due to a kitchen that doesn't have space for a fridge (actually, I'm lying - I hardly ever used a fridge even before I moved here!), I keep my stuff outside. Half the year that's no problem - there are just a few days when I have to prevent it from freezing up. (Those are the days I might buy a bag of frozen peas or so! ) During summer, the moisture is still generally above 80%, and the evaporation from the clay pot cooler I use is not good enough to really cool things down. It seems to work a little, but I wouldn't keep meat in it. OK for cheese and yoghurt, though.

Re: Building a passivly refrigerated out house

Posted: Sat Jan 24, 2015 7:56 pm
by doofaloofa
Marc wrote:I guess it's worth a try, but I can't see there being a large amount of evaporation from between the walls - in our(your?) climate, air to moist most of the time.


I'm envisioning some kind of venting sytem to draw the breeze through the damp cavity (ooh-er!)

Re: Building a passivly refrigerated out house

Posted: Sun Jan 25, 2015 10:35 am
by Green Aura
The house I grew up in had an add-on pantry. It was just a normal cavity wall brick construction but had a steeply sloped slate roof (I don't know if that was relative to the needs of a cool pantry or just part of the house design) and it had a really tiny window. Inside it was painted white, had a meat safe and a stone slab shelf.

I remember it was always cool in there, although I don't think it was refrigerator cold in summer. The stone shelf was always cool, though, even at the height of summer and the meat safe sat on one corner of it.

By the time I came along we didn't use the meat safe, other than as a cupboard, but that's what it was always called. It would only have been big enough for storing a joint and a few other bits and a shelf which I'm guessing would hold the milk etc. It had a wire mesh door and side.

Re: Building a passivly refrigerated out house

Posted: Mon Jan 26, 2015 7:35 am
by ina
When I grew up, we had a meat safe in the cellar... But they don't do cellars here. It was quite cool enough for our needs, but in the end convenience won out and even we got a fridge.

Re: Building a passivly refrigerated out house

Posted: Mon Jan 26, 2015 4:24 pm
by diggernotdreamer
Wasn't there something like this on the Tudor farm programme a little while ago. It was how they kept the dairy cold with a mixture of air coming in and water being sluiced onto the floor. Not sure how long you could keep meat in a cool environment, that was the whole idea of curing to stop the meat from going rancid. I rather like the idea of a root cellar, but knowing my luck it would end up as an underground pond.

Re: Building a passivly refrigerated out house

Posted: Mon Jan 26, 2015 9:03 pm
by ina
Well, swimming pool in the basement is very posh... ;)

Re: Building a passivly refrigerated out house

Posted: Tue Jan 27, 2015 11:45 am
by Green Aura
I don't think such rooms are designed for storing large amounts of meat, like you'd have if you're butchering your own animals. What might be cool enough to store a joint for a couple of days and a few sausages is a whole different thing. Like dnd said, that's what curing was for. However, such a room might be perfect for hanging cured meats, as long as it wasn't damp and had a decent air flow.

It might be worth looking on ebay for a chiller room - I don't know about in Ireland but they crop up here quite often and aren't hugely expensive (relatively). At least then you could store your meat safely, although I'm not sure how long for.

Re: Building a passivly refrigerated out house

Posted: Tue Jan 27, 2015 2:03 pm
by doofaloofa
The intension is not as a long term storage place for fresh meat, more a secure place to hang carcasses between slaughter and curing/freezing.

it will also serve as a general storage area fro veg, jars etc, and cured meats

A kind of walk in cold room

Re: Building a passivly refrigerated out house

Posted: Tue Jan 27, 2015 3:42 pm
by diggernotdreamer

Re: Building a passivly refrigerated out house

Posted: Tue Jan 27, 2015 4:26 pm
by Odsox
We have a walk-in larder beside the kitchen. It was a coal store when we moved in and presumably a wood store as well, or something, as it was 2 small "rooms" about 5' square. I knocked the dividing wall out which left a windowless 10' x 5' room with just one external 5' wall, east facing. I put a ventilator in the wall and another in the door.
It always feel cold when you walk in and I just measured it and it's 6 degrees cooler in there than the kitchen.

It gets used to hang poultry as it's totally fly free.

doofaloofa wrote:A South African friend told me in the Bush an old method of keeping a house cool was to build cavity walls, filled with coal. Water was dripped on the coal, wich evaporated rapidly due to the high surface area of the slightly porus coal

I would have thought that's a recipe for disaster, especially in humid Ireland. Unless to take a great deal of care the wall will always be damp and if there's daylight it will quickly turn green, or black if no window.

Re: Building a passivly refrigerated out house

Posted: Wed Jan 28, 2015 2:38 pm
by doofaloofa
DPM on the external surface of the interior leaf of the cav wall

External render in hydraulic lime which encourages evaporation. Perhaps useing an adhesive float(castllated) to further increase the surface area for greater evaporation

I envision only needing the extra cooling in late spring to early autumn

Re: Building a passivly refrigerated out house

Posted: Wed Jan 28, 2015 7:05 pm
by diggernotdreamer
what is dpm. What are you constructing the room of?