Larder

[Weebles]

No idea where to post this so please move if needed.

I would like to have a proper cold larder.  Only problem is how to build it in a heavily insulated house.  So far it is on the north wall of our designed house (got planning permission last week, now about to do one lot of variations).  We were planning a proper external door to access this larder.  Looking at MBC timber frame but unnecessary to heavily insulate the larder.  Any thoughts on how we might do this?  Was thinking we might need to have a separation of the concrete slabs too (so any heat from ufh doesn't "seep" under the door and heat the larder).  Or should we just build it afterwards / separately from the timber frame?  

[Stones]

How about a walk in fridge / cold room?

 

http://www.coldrooms.net/case-study/domestic-walk-fridge/

 

[PeterW]

21 minutes ago, Stones said:

How about a walk in fridge / cold room?

 

http://www.coldrooms.net/case-study/domestic-walk-fridge/

 

 

 

Its the chillers that cost the money on those - wall panels can be had for about £30/M in 80mm PUR faced both sides. Chillers are upwards of £1500 as my mate found out when his lad hit their game store chiller with a tractor ...

 

wonder if you can reverse engineer one from an ASHP running in cooling mode ..?? 

[Weebles]

We are planning to use MBC for timber frame (like lots of people on here) so thinking could use their cheaper open panel uninsulated external wall for the larder external walls.  Would ensure it wasn't over insulated.  Then I think we would need to have two air vents.  And on the north side of the house, with no heat source, it should stay at a stable low temp for most of the year.  Will then have stone shelves and stone / concrete floor. Can cool using ice (frozen drinks bottles put on the top shelf of the larder works a treat apparently) in the summer.  Just need to avoid it being damp.  Don't know about reverse engineering from an ASHP because wasn't planning on having an ASHP, though sounds plausible.

[Weebles]

So I suppose I am trying to use the natural cold bit of our plot (north side and under trees and never sees the sun) to keep some food cold and live like my granny used to.  Don't think we'll get away without a fridge at all.  But hopefully food will store better, taste nicer from not having been refrigerated and we can also store wine in there at a constant temperature.  Without using any power.  That's the dream anyway.  Going to be an experiment to build it and I have no idea whether we'll get enough airflow or keep the temperature low enough.  Will see how this one goes.

[PeterW]

Any way you could build it as an add on to the house ..? Stone walls..? Use a doorway you've got planned and then add it on ...?

[dogman]

We will have a walk in larder with a MBC twin wall house.

https://www.bpcventilation.com/water-cooler-battery

I intend to fit one of these to cool the room however it will need to vent into the house unless you remove the room from the airtight area of the house

 

Although things are evolving in our design and there are other options we are looking at

 

 

[TerryE]

11 hours ago, dogman said:

I intend to fit one of these to cool the room

 

As far as I can see you fit this inline into an MVHR inlet to chill down the air -- assuming that you have a supply of chilled water.  So where are you getting your chilled water from?  And you are in effect pumping heat from the larder into this water supply.

[dpmiller]

Dunno if that chiller wold be OK for potable water but could you run the rising main through it?

[Ian]

On 23/05/2017 at 22:17, Weebles said:

No idea where to post this so please move if needed.

I would like to have a proper cold larder.  Only problem is how to build it in a heavily insulated house.  So far it is on the north wall of our designed house (got planning permission last week, now about to do one lot of variations).  We were planning a proper external door to access this larder.  Looking at MBC timber frame but unnecessary to heavily insulate the larder.  Any thoughts on how we might do this?  Was thinking we might need to have a separation of the concrete slabs too (so any heat from ufh doesn't "seep" under the door and heat the larder).  Or should we just build it afterwards / separately from the timber frame?  

First decision is whether or not you want it to be a traditional larder (ie one which relies purely on natural ventilation and heavy masonry walls) or whether you want it to be a modern mechanically cooled larder (ie a walk in fridge)

 

The traditional ones have no insulation but the modern ones are highly insulated.

 

My impression is that you want a traditional larder in which case the simplest approach is to design it external to your highly insulated MBC timber frame. Perhaps it could be built as a 'lean-to' type design with access from a door on one of the outside walls of your timber frame. I once designed an old fashioned walk-in larder c/w stone shelves as a small part of a large project for a client who was renovating and extending an old farmhouse in Cheshire and they were very pleased with it. 

 

As you quite rightly mentioned, north side of the house in a shaded spot with cross ventilation will help a lot in keeping it cool.

 

Ian

[dogman]

7 hours ago, TerryE said:

 

As far as I can see you fit this inline into an MVHR inlet to chill down the air -- assuming that you have a supply of chilled water.  So where are you getting your chilled water from?  And you are in effect pumping heat from the larder into this water supply.

I never thought about the potable aspect will need to check.

However i was thinking of using the feed to the hot tank / sunamp / or whatever  fit as a sort of pre heat. however it would be intermittent

 

or feed from heat pump in summer which will be used for cooling.the slab 

 

or as we initially were going to do was use an ecocent and use the cold air produced to cool the larder. I would then vent the cold flow out of the larder to the back of the larder fridge to help keep it cool 

 

 

 

[ToughButterCup]

1 hour ago, Ian said:

[...]

in which case the simplest approach is to design it external to your highly insulated MBC timber frame. Perhaps it could be built as a 'lean-to' type design with access from a door on one of the outside walls of your timber frame.

[...]

 

Which is exactly what has happened in our build; but by accident.

We had an old piggery that would have fallen down during the piling process. So we would have had a minor disaster on our hands had we not taken it down (with permission). We are rebuilding it but 'cold'. 10 square meters that are proving to be very valuable indeed.

 

The short walk out to the larder will be worth the trouble.

[ProDave]

Can I raise my wacky larder / fridge theory again.

 

Think about how a fridge works. Basically the compressor etc is there to remove heat from a fridge. Most fridges expell the removed heat via some form of plate on the back.

 

So the back of a fridge will be warm, expelling the extracted heat. The inside of a fridge will be cold. The front and sides of a fridge will therefore be cooler as that's where heat is drawn in to replace what has been extracted. So to sumarise, back of fridge is hot, front and sides are cool.

 

My wacky idea therefore was to build the fridge into one wall of the larder, such that the font and most of the sides were in the larder, and the back was outside the larder (in my case it would have been in the hall)  The theory that the cool surfaces of the fridge would continually be removing heat from the larder thus keeping it cool.

 

It would need a fridge sized hole in the wall and the fridge sealed to that hole. And the rear side of the fridge would look silly sticking out of a wall, so I would have put a false wall up just beyond that with air vents to allow the hot air out.

 

I won't be putting this into practice as SWMBO has decreed the fridge is not going in the larder, but if anyone ever tries it, do let me know if it worked.

[Jeremy Harris]

Just an observation from yesterday.  The North side of our house has a temperature sensor, that is shielded from any breeze and far enough away from the wall to indicate the outside air temperature fairly accurately.

 

Yesterday, it was reading over 24 deg C by early afternoon, and stayed at that sort of temperature until early evening.  I've no doubt that it will be warmer today and tomorrow, if the forecast is accurate.

 

From this I don't think you can rely on the North side of a house being particularly cool in warm weather, so would suspect that some form of cooling might be needed even for an external larder.

[dpmiller]

The fridge idea has merit for sure but if you don't need the heat/ can't put the heat where you want it then you're using a fair bit of energy for no good reason. Personally, I'm thinking a cold floor (solid, rising through the floor insulation and isolated from the rest of the screed) and maybe a cold water pipe looped through the space would be plenty cooling. Bringing outside air in under the slab and out at high level will help too

 

Anybody have thoughts on how to implement such a designed-in thermal bridge in terms of condensate/ vapour control?

 

Our current house (70s brick bungalow) has a stud built larder right at the SE corner of the kitchen. Even with an insulated cavity it manages to be a touch cooler than room temp in the summer and often sub 15c in the winter...

[Jeremy Harris]

The ground temperature in the UK is around 8 deg C all year around, once you get down below the top metre or so.   In the past, underground larders were pretty commonplace in large houses, so perhaps we should think about recycling that old idea.
 

[PeterW]

59 minutes ago, JSHarris said:

The ground temperature in the UK is around 8 deg C all year around, once you get down below the top metre or so.   In the past, underground larders were pretty commonplace in large houses, so perhaps we should think about recycling that old idea.
 

 

If its not too late, think cellar !

 

The existing garage in our conversion/extension had a big inspection pit in the centre of it - 900x2500mm and over a metre deep. It was bone dry and is constructed with a 6" hollow core breeze block. Its had a 4" concrete cap cast over the top of it and then insulation and the floor slab so is nearly a foot thick at its entrance. Even with it open to the room above its a constant 11c so it will be used as a wine cellar and cheese store..!

[ProDave]

I did consider leaving out the floor insulation (suspended timber floor) under where the larder is going, but changed my mind as it would then be a major PITA to put it in later if we changed our minds and didn't construct the pantry.

 

Our new house is performing well in this hot weather (it's even hot up here) remaining nice and cool inside. The inside temperature of the south facing walls is just 0.5 degree hotter than the inside temperature of the north facing walls.. Thanks no doubt to the insulation with a long decrement delay. The caravan on the other hand needs all the doors and windows open to stop it becoming like an oven.

 

The ground slab under our suspended floor (there is one bit still not insulated and accessible) is still measuring 6 degrees today, so if we wanted to cool the larder a simple fan through the floor to draw up some cold air would probably work well.

[ToughButterCup]

52 minutes ago, ProDave said:

[...]

The inside temperature of the south facing walls is just 0.5 degree hotter than the inside temperature of the north facing walls.. Thanks no doubt to the insulation with a long decrement delay.

[...]

 

You mean Thermal Mass don'tcha?

[Weebles]

Too late for a cellar.....ruled out basement / cellar a while ago on cost.  But maybe I should insulate this larder outside the thermal envelope, to keep out some of the hot air? With no heat source inside the room, no windows and only vents at top and bottom I had hoped it would work. But I am a bit concerned now about keeping cool in hot weather (and it was hot this weekend - even our cold damp bungalow got roasting hot). I don't really want to use power to cool it. 

[TerryE]

We ho-hummed over this one, but in the end the footprint issues didn't work.  If you have a 1m² larder then its going to have ~10m2 surface area with the rest of the house and if you assume a internal partition U-value of 0.4, say and a 15°C delta from the room to the rest of the house, then you are going to have to pump a continuous ~60W of heat out of the larder to keep it cool.    IIRC , Peltier effect coolers have a CoP of <1 so you'd really need a fridge-type system which have a CoP of nearer 3 and a heat pump rating in this range.

 

Unfortunately, there's no free lunch.

[Ferdinand]

Is there a possibility here using walk in freezers with no power used, or even small refrigerated containers upcycled inside a stud wall?

 

They are strong things with a lot of insulation - dismantled a 40ft one once.

 

The issue would be managing humidity.

 

Outside the thermal envelope?

 

Does the efficiency change if you are at say Transit or Bedford van size, and use the other half for something that needs to be warm such as a drying room .

 

Said he somewhat speculatively.

 

Ferdinand

Edited May 30, 2017 by Ferdinand

[TerryE]

The guts of a fridge would be the sort of cooling system that I was thinking about.  As to drying room, well you if you dump the heat int a smll room then it will be hotter than the rest of the house, but a drying room really uses the delta temp to drop the relative humidity of the air, and an MVHR house, as Jeremy commented, a cloths drier in a utility room will work pretty much as well.

[dogman]

One idea i had was to use a Ecocent for the hot water. It can extract from a hot area in the house and the cold 6-7 deg air will be vented into the larder. If insulated it will cool the space enough. Downside will that you need a vent into the heated space from the larder and in the winter it may cool the location of the larder ie kitchen

Edited May 31, 2017 by dogman

[Jeremy Harris]

1 hour ago, dogman said:

One idea i had was to use a Ecocent for the hot water. It can extract from a hot area in the house and the cold 6-7 deg air will be vented into the larder. If insulated it will cool the space enough. Downside will that you need a vent into the heated space from the larder and in the winter it may cool the location of the larder ie kitchen

 

Bear in mind that a room source heat pump water heater like that will only be running for around 2 to 4 hours a day, and as soon as the tank is up to temperature it will turn off.  It may be that this is enough to cool a well-insulated cool room down, but that cool room will need to be lined with a material that has a high heat capacity, so that when cooled it can stay cool for the many hours between being actively cooled.