"Andrew Gabriel" wrote in message
...
In article ,
Chris J Dixon writes:
Any suggestions on the most suitable insulation to use?

Externally, you need to use a waterproof insulation so it can't
become waterlogged, also known as closed-cell. This is most commonly
used on chilled aircon pipework. Armaflex is best known make.

Remember insulation only makes it less likely to freeze up and a prolonged
cold spell could still see the pipes freezing.
Make sure you can remove and refit it in case you have to thaw it.
IIRC in ~1970 there were about 22 days where it was below freezing day and
night.
I was recording weather stuff for a school project and the wet bulb never
defrosted over that period.
That was in west bromwich not the Scottish highlands.