"Neil Jones" wrote in message
...

"David Hill" wrote in message
...
I have this idea to draw the heat from the top of my Large poly
tunnel
and
to duct it through a channel of concrete blocks and gravel to form a
heat
sink.
The problem is I am wondering if I can get some form of thermostat
that will
switch ON when the Temp rises and OFF when it falls.
My local Electrical wholesaler doesn't know of anything to do the
job.
Any ideas?

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk


You want a thermostat with changeover contacts, eg Honeywell T4360
heat/cool.

Neil



Here's the documentation for this:-

http://europe.hbc.honeywell.com/prod...8281uk07r2.pdf

The T4360D would do what you want, although it doesn't actually use
changeover contacts, but a winter/summer switch instead.

The T6360 range all appear to use changeover for heating/cooling.

Regards

Neil