Slightly OT : Keeping Something Warm

Hi there

In the near future im going to be sending aquatic livestock (corals) by post and im looking for clever (and cheap) ways of keeping it warm in the royal mail postal service for 18 hours or so.

The corals will be shipped in small, water filled plastic bags, and it is this water that will need to be kept warm (26 degrees c preferred).

Any ingenious ideas as to how to best package this up so that the temp doesnt drop too much?

Anything i can add to the package to keep it warm (but without having to purchase expensive heat packs). Cant be too hot obviously, as it would melt the bags!!

Regards

Mark

Reply to
Mark Trueman
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Two things will help maintain the temperature - more insulation, and more water. You need to experiment to find the right compromise between cost and effectiveness, and remember that weather could have a significant effect.

Reply to
Rob Morley

The normal way used by commercial shippers is to use styrofoam boxes.

Reply to
Andy Hall

Ok, so what would you view as the best form of insulation. Bubble wrap must be pretty good for insulation in itself. I doubt i could line the walls of the box with celotex however!!!

Reply to
Mark Trueman

I do have plently of "poly-boxes" hanging around, but they are just too big to ship a small fragment of a coral in. Im hoping to get ideas on how to ship small packages and retain the heat.

Reply to
Mark Trueman

Hay and bacofoil? As I said, you really need to experiment to determine the most cost effective balance - cost of packaging, cost of mailing, probability that the coral arrives in good condition ...

Reply to
Rob Morley

A few ways:

- You can increase the thermal mass inside the insulation. This would most easily be done with having other bags of water packed in with the one containing the coral if you don't want to use aquarium water.

- Improve the insulation. Polyisocyanurate foam (Celotex or Kingspan used in buildings) has better insulating properties than styrofoam (perhaps twice as good) and also has foil covering which will help a little more. You could cut pieces of this and stick it inside cardboard boxes.

I wonder whether oxygen is also important for coral as it is for fish. Perhaps adding some oxygen to the bag would help?

You could also try contacting one of the major importers such as the Tropical Marine Centre in Watford for ideas and help

Reply to
Andy Hall

Ah, aluminium, that most insulating of metals...

Reply to
Grunff

Bubblewrap is quite poor actually, unless you layer it in many layers - but even then it's not great.

Polystyrene or polyurethane foam is really your only workable solution - the only question is "how thick". This is something which is fairly easy to determine by experimentation.

Reply to
Grunff

Would be useful to know max/min temperatures allowed, and for how long. Also, what is the rough monetry value lost if temperature goes out of range and presumably wrecks the corals in a parcel? (i.e. a solution costing £10 a go probably isn't viable to ship £1's worth of coral.)

In addition to thermal insulation mentioned by others, in my mind I was starting to design a battery/thermostat/heater to compensate for the small heat loss. Battery could be a use-once alkaline and heater could be a few resistors or resistance wire. It would need some good protection against any damage in transit being able to start a fire with the battery energy. Then I thought this is going to look exactly like an incendiary device when X-rayed, and your coral is going to get blown up in a controlled explosion at the sorting office, which will probably have an even worse effect on it than getting a bit cold in transit. ;-)

Oh well...

Reply to
Andrew Gabriel

Most coral will survive a slight temperature drop for a while, soft corals will fair better than something like a bubble coral. Bigest problem will be maintaining Oxygen level. Make sure the protien skimmer is working well for at least a day before shipping, that'll keep the Oxygen level as high as possable, pack the frag with as much water as you can, double or tripple bag it, pack plenty of polystyrene round, make sure the packing is rigid so if someone puts another package on top it doesn't increase water pressure.

Even the professional will lose stock in transit, so be prepared.

Reply to
Shrek

The temperature range is probably down to about 20-22 for most corals. Ite depends on which part of the world they are from.

Reply to
Andy Hall

The Post Office has restrictions on sending living creatures through the post, which usually includes specifications for the packaging used. You should contact Royal Mail customer service for guidance. I suspect they will want more than just a plastic bag to retain the water, to protect other goods in transit against a leak.

Colin Bignell

Reply to
nightjar

"nightjar .uk.com>"

The Royal Mail web site also lists "flammable solids" as being prohibited. No wonder email is so popular!

Reply to
PM

Don't send obviously warm things through the post. They're using IR cameras (and have done for some years) to spot potential parcel bombs. Your corals are likely to get dynamite-fished! OTOH, external warmth means your insulation has failed anyway.

If you want to keep something warm for a few hours, then Glauber's salt is easy (the click-disk re-usable heat packs) They store plenty of energy, have a low max temperature and can give you (IMHE) about 6 hours warmth in a suitably insulated container. 18 hours is tricky though.

How big are these corals ? Will they fit into a wide-mouthed Thermos ? Are they sensitive to excess temperature too ?

Reply to
dingbat

Firstly, as a ballpark.

1l water, 10cm styrofoam on each side. (10cm 8'*4' sheet = about 20 quid) Styrofoam conducts about .04W/C/m^3. So, at 10cm, that's .4W/C/m^2. Area is about .09 square meters (hard to exactly determine), so you're looking at .04W/C or so. For a difference in temperature of some 15C, that's .6W. Water has a thermal capacity of 4400J/Kg/C. So, it'll rise (or fall) by 1C in 4400J/.6W = about 2 hours. Or 8C in 24 hours. Going to 2l water, and the same thickness of foam, you're looking at double the heat capacity, and about 1.3 times the heat loss, or 6C in 24 hours. You probably want to starve the corals for a day or so beforehand to make sure they have no food in their guts, which will decompose in the post.

This would (with 2l and foam) give you a package around 3Kg, 35cm cube, and costing perhaps 3 quid in materials.

Reply to
Ian Stirling

Ask NASA if they have any spare insulating tiles. I gather there may be some second-hand ones available soon.

On a serious note small packages and constant temperature don't go together.

What is the warmest you can start at and the coldest the coral can tolerate? How much water will you ship with them? Then you can work out how much insulation you need.

Reply to
dennis

Isn't there a law forbidding corals into this country, depending on what they are being brought in for?

Reply to
ben

There are restrictions on importation of certain species of coral under the CITES agreement.

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appendices 1-3 define species and purpose.

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in mind that for many species (not particularly corals), the wild environment is endangered in itself to the point of no longer being able to support them.

Not that many years ago, it was impossible to breed marine fish in captivity. Now it is possible with an increasing number as technology has improved.

Reply to
Andy Hall

There certainly should be.

Reply to
John Cartmell

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