Isotherm water-cooled refrigerator upgrade to coolbox 

A rather inelegant title for a cool technology addition to Frank.

Isotherm have a range of freezer/fridge solutions that can turn a coolbox into a freezer or fridge. The SP (Self Pumping) range appeals to me because there is no need for a pump, thus reducing power consumption at sea.
The system works by replacing the existing, through-hull sink drain cock with a larger (2.5″) unit inside which is embedded a coolant coil. The under-water exterior surface of this unit uses sea water to cool the refrigerant via the coil, which is wrapped around the drain out-pipe. 

This picture is worth a thousand words:


The unit I will install is the SP 2051 with an “o”-shaped cooling panel:


The drainpipe cock is attached to the assembly.

The under-water face of the self pumping cock. An anode fits to the face.


The sacrificial anode was not in the box – I shall get one, make sure I have all the components and then have the assembly fitted when Frank is hauled for her annual scrub and antifoul at Ingleside.

I can install the compressor later, or maybe have the yard do it.

One thought on “Isotherm water-cooled refrigerator upgrade to coolbox 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s