Routing cold air through pipes?

Hi all,

I keep rabbits in an 8x6 shed. This is currently insulated with 2" expanded polystyrene. Although this helps, it still gets very hot inside during the summer months.

I am planning on buying a cheapy portable air con unit to bring the temp down, but the problem is that these are very noisy (or so I've heard), so I don't really want to stick it in the shed with the buns.

I have a double garage about 4 meters away from the shed, and had the crazy notion of siting the air con unit in there, and piping the cool / hot air to / from the shed via some kind of submerged pipe.

Am I nuts? Would I need a minimum diameter pipe? (Would drain pipe be ok for instance?) Whats the best / cheapest way of insulating the pipe? Would is be ok attaching such piping the air con unit of will it cause problems?

Many thanks for any suggestions, Lister

Reply to
lister
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On Sun, 05 Aug 2007 09:40:34 -0700 someone who may be lister wrote this:-

Decide which parts of the shed get the sun, generally the roof and a wall or two. Put a flat wall/roof over this with a ventilated air gap between. Paint the new wall/roof white.

Reply to
David Hansen

Good idea, but why not try something different. Put a few large fans in the roof of the shed with a covering to stop the rabbits injuring themselves. Set the fans to suck air from the hutch and blow it out. This will drag cool air in and take the warm air out. Cover the tops of the fans to stop the rain getting in, perhaps a piece of wood a few inches above. Try a few kitchen/bathroom type fans in the top of the walls. They can shift a very high volume and if mounted correctly are not noisy. You might end up freezing the poor rabbits with their own aircon.

Reply to
Pete

Thanks for the suggestions, but I should perhaps rephrase my problem slightly in that I need to keep the shed COOLER than the outside air temp. Rabbits really don't handle heat well, and with the very hot summers we have been having (well except this year!), I have been trying to insulate the shed against heat from outside to keep it cool.

This is impossible really since the buns have access to the outside via a tunnel, so I am always going to get hot air entering through this. I already put that silver bubble wrap stuff over the roof in the summer, and the rest of the shed is in shade anyway.I do have fans, and whilst these help slightly, they are not as effective for rabbits because obviously they don't perspire like us.

It really has reached the point where some kind of refrigeration is required, but I need to work out the best and cheapest way to do this.

Thanks again.

Reply to
lister

themselves.

shift a very

text -

rabbits

Simple really, make your Rabbit Pies before the summer gets too hot and freeze them for consumption in winter. You should be able to keep a breeding set going over winter for a new set of pies in the early summer. Watch out for power cuts to the freezer and don't cook any with mixamatosis.

AWEM

Reply to
Andrew Mawson

Sure you can pipe it in. You may need to add a (tangential) fan to overcome pipe resistance. But its going to be more energy efficient if you run it closed circuit rather than sucking warm air in to cool. That means 2 pipes.

I dont know whether for the same cost you could get a big hole dug under the shed. If so, exposure to underground soil would help keep it below outdoor temp all summer long, free of run cost.

Another lower energy way to do things is to cool a pool of water using night air temp. Stop any external circulation in day. This will get your water below outdoor temp, and can cool the shed in the day. Max cooling is obtained by using a differential thermostat.

Fans dont cool dry warm blooded animals as much, but do still provide some cooling as long as rabbit temp is above air temp, and are relatively energy and cost efficient compared to ac.

NT

Reply to
meow2222

I put 2l bottles of ice in socks and pop them in the hutch. I freeze a new set while one set melts.

The rabbits like it and often lie on them.

Reply to
dennis

Drill big hole under shed, rabbits go down hole, no problem. That's how it works in the wild.

ISTR that rabbits can hear high frequency sound inaudible to humans. A fan that sounds quiet to you might be intolerable to the bunnies. I suppose you'd only know if they showed signs of distress.

High frequency sounds are also most easily attenuated, which is why you can only hear the boom, boom, boom of the bass drum when the neighbours have a 2 am garden party.

If you want A/C for the rabbits you'd probably be better off with a chiller, which produces chilled water which is pumped to & from a fan coil unit or something similar. You could do it with a cheap split AC unit, piped with insulated drain pipes and fans, but I'd anticipate that control of the air temperature would be nearly impossible to achieve. How would you do it? A variable (cold) air volume system with a terminal reheater? It gets very silly very quickly. The cheap end AC units are cheap cos they're made in huge numbers, a chiller with a similar output would be much more expensive. Chilled water, radiant cooled slab (like UFH with cooling).

Reply to
Onetap

Thanks for the suggestion but yeah we already do this. The problem is how quickly they melt when it's really hot, we can't refreeze new ones faster than the old ones melt. Plus we have 4 rabbits so that means finding space for 4 x 2 litre pop bottles in our modest fridge freezer.

Reply to
lister

Yeah they have occilating fans at the mo but these don't seem to bother them at all. They are more than happy to lie there in front of them when they are free to go outside if it was causing them distress. It was more the volume of the air con that was concerning me.

Reply to
lister

On Sun, 05 Aug 2007 09:40:34 -0700 someone who may be lister wrote this:-

Moving chilled air means moving large volumes to obtain a given cooling effect, which means large pipes and thus large losses.

Moving chilled water means small pipes and thus small losses. However, the sort of equipment which can produce chilled water will be more expensive than an "air conditioning" unit bought off the shelf.

If you are cooling the shed you may need to consider what effect this will have on the humidity.

Reply to
David Hansen

Chilled water is cheap. just bury a few tens of metres of plastic pipe 4 foot down and run water through it.. It will stay below air temp all/most of the time if there is enough soil. It can be a pain to install using a spade though.

Reply to
dennis

On Aug 6, 10:25 am, "dennis@home" wrote: water is cheap. just bury a few tens of metres of plastic pipe 4

Convert an old fridge so that it forms part of the hutch.

Reply to
adder1969

I was going to say that; a mate of mine made a dehumidifier that way. Nice and quiet, you shouldn't need the big noisy fan for your smallish shed. Keep the "heat rejection" coil at the back out of the sun, and with reasonable air access.

Reply to
Newshound

Hmm. That's a definate idea. Am I going to be able to extract the heat exchanger / fit it to the shed without breaking the pipes? Surely I can't break the seal or I'll have refridgerant everywhere?

Reply to
lister

Shave the fur off the rabbits?

Reply to
The Medway Handyman

Poodle cut or mohican?

Owain

Reply to
Owain

Brasilian.

Reply to
The Medway Handyman

Just take the door off and put the fridge in a hole in the shed,

Reply to
dennis

On Mon, 6 Aug 2007 22:40:47 +0100, "dennis@home" mused:

It would create more heat from the compressor than the fridge could cool, so would in fact make it hotter.

Reply to
Lurch

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