Cooling units

[Andrew_B]

A little advise please.

I want to buy a cooling unit to install in the ice box in my Hunter 34 but I'm not sure which one.
The internal volume is around 200litres and the box itself is well insulated.
I've been looking at the 2 Isotherm units - air cooled and water cooled.
Is the extra work involved in installing the water cooled unit and extra price worth it or is the air cooled unit as good?
Can anyone recommend any other models.
Ideally I would like to keep the job cost down to under 500 pounds but at the same time I want something as efficient as possible.

Thanks

 

[ccscott49]

Pretty big cold storage, it depends on where you are intending to go, if to the tropics or eastern meddy, I would go for the water cooled option, with the bronze plate thingy, if staying around northern europe, the air cooled version would do. IMHO I would go for the water cooled if starting from scratch. The isotherm ones seem pretty good value, but I would look around extensively!

 

[Shanty]

Going through the same exercise myself on a smaller (65ltr) coolbox. A few points:

I've found Nigel Calder's book "Refrigeration for Pleasureboats" a good primer on the subject.

How well insulated is your existing box? Mine has 25mm of expanded polystyrene - not nearly enough. The minimum recommended seems to be between 50 and 100mm of polyurethane foam (higher insulation value than EP foam).

Do you need 200ltr of fridge space? It might be worth filling some of it with insulation.

Air cooled vs. water cooled: The feeling that I am getting is that water cooled is a good idea for the Med., but for UK waters, air cooled is OK. Anyway, on a £500 budget, I don't think you will be able to afford water cooled, especially if you opt to keep the full 200ltr of fridge space.

Alternative suppliers:

Waeco seem to be the market leaders in the UK - discounts available
Shoreline produce a slightly more limited range at good prices
Frigoboat (imported by Penguin Marine) do an alternative form of water cooling (expensive)
Grunert (from the States) do some good holding plates

All seem to use Danfoss compressors & similar evaporators, so I suspect the decision is dominated by price.

Anyway, good luck - would be interested to hear what you decide on.

 

[AndrewB]

I use an air-cooled Peltier plate system and was amazed at how much more effective the same setup was when I saw it water-cooled in another yacht. It looks to me like air cooled system means either a big current draw or pretty ineffective.

 

[42_South]

Having installed a Waeco air cooled unit, I have been very pleased with it.

Would however recommend that a more important consideration is compressor and plate size/type. If you do a lot of sailing, then perhaps the storage type will be better, particluarly if you also go for the shore charge unit that is available as an extra. I have used a fan-forced plate type which is cold enough to freeze the beer down here in Aus.

Some points about installation (these type of units can be self-installed by Joe Average):

* They come with a fair bit of pipe to cover all types of installations - keep any excess copper tube inside the cool box, as this also condenses and it is no good having this outside the box where water condensation can damage the boat.

* They make a little bit of noise - in our installation, the cool box was located near the bulkhead in the main cabin - I led the pipes through this into the heads and installed the compressor there in a small box with louvres. There was more than adequate air circulation there to meet it's needs.

* Triple check everything before connecting the compressor with the condensor, as these units are pre-charged with gas. If you have to take it apart to alter the installation you need to get a refridgeration mechanic to regass the unit on the boat, which can be an un-necessary cost.

 

[vyv_cox]

I declare a conflict of interest here: see <A target="_blank" HREF=http://www.palmayachts.com>http://www.palmayachts.com</A> - my son's company. His advice for the Mediterranean is that water cooled is much more efficient. Definitely go for a holding plate, they are very effective indeed. Virtually all Sunsail's Med fleet have an engine driven compressor, water cooled condenser and holding plate. This is a foolproof setup, suits the typical charter boat operation of motoring at least once or twice every day. May not be so good for long-term cruising, so mine will be electrically driven but otherwise similar.

The Isotherm water cooler/drain fitting looks good but my son tells me he has seen galvanic corrosion in them. It is quite cheap and easy to fix up a water cooler driven by a small pump and that is the way I am going.