I hope your larder/pantry is outside of the insulated envelope, with airtight insulated door to 'indoors' http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=749&page=1#Item_14

the larder is on an outside wall, included in the overall insulated envelope but insulated again between itself and the rest of the building. The door is an oak t&g board and brace with 25mm thick boards, framing round all four sides (including the bottom) and rubber 'fin' seals too. The floor is a polished concrete and the work top a brown slate.
I've not skimmed the inside yet and was wondering if there may be any benefits form an other than normal gyproc finish? (lime is out as the other side of the blocks is gyproc'd, so wouldn't breath anyway.)
Yes the fridge freezers, both of which back onto the outside (from the inside space!) of the blocks forming the larder walls have their heat channelled up the outside of the blocks to about 700mm below the chimney outlet and then are directed into the upper part of the larder space...
Make any sense?

sorry..!!!!!
yeah meant gypsum, dyslexic moment!
It's just normal multi-finish onto 12.5mm standard plaster board.
re. the fridges, if you imagine a section with a 100mm block wall in the centre running up from floor to ceiling, to the right, the ceiling is at 90 degrees, parallel to the floor, whilst to the left you are in the eaves and the ceiling tapers down at 45deg's to about half way down the block height and is vertical from their down.... Make any sense?
On the right of the blocks with their rears to the blocks there are a line of two fridges, the 'exhaust heat' travels up a contained chimney space of 50mm by 200mm per each fridge to about 2/3 up the block wall and then punches through into the top part of the other side (i.e. the larder space). just above the point of entry for the warm air there is the outlet to the 'air tunnel' where cool air rushing across the mouth combined with the warm air released should combine to ensure continuous circulation via the inlet at the bottom of the left hand external wall.
The inlet is 6" wide.
i'm unsure as to what dimension the outlet should be...

wish we were trying to reduce the cooling load!!!
Sadly we're in the Channel Islands and I am trying to be as efficient as possible. We have a well insulated roof and u/f heating throughout. My thinking was more to combine/assist the circulation in the larder space, using the hot air to draw the cold through.
I'm very much at the beginning of my career so learning all the time, in fact it is a shame to loose the heat, you're right, but I think in this scheme it is probably already too late to change it.
For future reference, how would you re-use the heat? Simply vent it directly into the space? I'd have thought that could be risky?

You could put the freezer in the "larder" but NOT its heat exchanger put that in the house in winter and outdoors in summer. The larder would work OK with a low vent and a high one -- no need to drive it with heat.

Mainly because the client is a cook and wants varrying storage conditions.
One of the fridge freezers will be primarily used when a large cooking job arrises (i.e. christmas time) other than that it will be turned off. The larder is to be a sort of cupboard come pantry affair as opposed to a replacement for a fridge. Butters, cheeses certain meats and vegetables but also tins and cereals etc...