Easy to install / build refrigeration unit for the boat ?

[sealegs 0]

Came across this site today from Christchurch for a very user friendly device to refrigerate any 100ltr box or insulated space.

 

http://www.tropicool.co.nz/Home

 

A visible view of its use currently on auction is here:

http://www.trademe.co.nz/motors/boats-m ... 296403.htm

 

Below is specs to make your own fridge.

Build your own fridge:

 

Create your own insulated space and cool it with a Tropicool Refrigeration unit.

 

Lockers, cupboards and spaces under benches or bunks make ideal places to insulate and turn into a fridge.

 

Use extruded polystyrene, polyurethane or similar high quality insulation.

 

Use 1mm insulation per litre of volume (100 x 100 x 10mm = 1 litre).

 

Ensure your lid or door is insulated and use a soft rubber or foam seal to form an air tight fridge.

 

Line the fridge with thin plastic like ABS or Styrene. A layer of fibre glass works well too.

 

Avoid thermal bridges around the door/lid like aluminium or stainless steel which will conduct heat into the fridge ~ it is best to use plastic in these areas.

 

I like it. I would use this as opposed to conventional compressor unit just because it saves so much space. I admit a compressor unit is better for cooling especially to lower temperatures but requires more space to install, additional cooling for condenser unit & power to run the whole package.

[Deep Purple 512]

I had one, frankly a waste of time. YMMV

[sealegs 0]

what was wrong with it?

[Guest]

I think I bought one years ago from someone after he had bought it off someone else, I then on sold it to somebody else. Great for the economy but not too hot on cooling stuff.

[wheels 543]

Very power hungry for the amount of cooling you get out of it. No where near as efficient as a Compressor type unit like the Danfoss 35.

 

PW, you got that unit from me. I came with my boat. I fitted a Danfoss 35 to the fridge box.

[Guest]

Very power hungry for the amount of cooling you get out of it. No where near as efficient as a Compressor type unit like the Danfoss 35.

 

PW, you got that unit from me. I came with my boat. I fitted a Danfoss 35 to the fridge box.

Sheee-it I've seen your fridge set up. That unit was never going to cut it. The only yachty I've ever met who takes ice cream off their boat to take to a dinner party at a house ashore for dessert.

[Atom Ant 0]

I put a tropicool unit in my SR26 years ago. Cheap to buy, easy to install, but like others above have said it is power hungry. To be fair they make no claims about it being energy efficient, in fact many years ago when I spoke to their sale person he made it clear that it wasn't efficient.

 

Wouldn't choose it if proper refrigeration is what you're after.

[sealegs 0]

thanks for comments guys. Its disappointing to learn the truth of this product which appeared so promising...so there goes another " good discovery of mine " down the drain.

 

So those of you who have efficient compressor refrigeration systems on your boats, what is it?, How do you cool the condenser ? ( is it salt water intake or air cooled ? )

 

Your fridge/freezer ... how do you keep it chilling at optimum temperature?

Do you have to run the engine often or is there a tried and tested " usage routine" you have to keep doing when sailing to keep food cold for duration of voyage

 

In another life in africa I was a refrigeration tech so dont mind you getting technical on this one. Im just not familiar with boats and refrigeration as a user.

 

so enlighten me please...

[too_tall 15]

They appear to be peltier type http://en.wikipedia.org/wiki/Thermoelectric_coolingunits - the same as the budget 12v powered chilly bins. Effective if you have an engine running constantly providing the massive amounts of power required.

 

I have seen them as active cooling in gaming computers. Even there, they are considered too inefficient to be useful really.

 

1.5 amps on economy - 5.5 on "normal" and that only delivers 40 watts of cooling ability. About what you would get from a modern .8 amp compressor unit. A 10 amp compressor unit can give a cooling ability of approx 500 joules per second - or 500 watts!.

[ex TL systems 63]

we have been using an engel 12v portable fridgebox compressor type for the last week on the boat . It has been running around 14 hours a day [turned off overnight] and has stayed cold with freezer pads still containing ice , a 100w solar panel has kept up with its demands , there was no particular cooling of the motor unit, in fact it was in a fairly unvented area. I may consider adding some extra insulation to the outside of the box to improve efficiency, but it is a fairly simple and cheap solution if you don,t need heaps of fridge space.

[wheels 543]

Your fridge/freezer ... how do you keep it chilling at optimum temperature?

so enlighten me please...

Well first of all, you can't beat insulation. It's key to ensuring all the cold you produce goes into the stuff you actually want to cool, rather than escape to the outside.

When it comes to a compressor type cooling unit, there are two ways of approaching the means of cooling. One is to have an engine driven unit, with the idea of cooling a down a reserve of of coolant with Hp as fast as possible. Then that reserve of coolant continues to keep the fridge/freezer cool for a long period. The down side to this is that you need to run the engine sometime, to get that coolant down. I have seen some able to get away with every few days and others needing a 15min run daily.

The other approach is to use your electrical system to power a very efficient low consumption compressor, running more or less continually(as in cycling). The Danfoss 35 unit has several different evaporators (that's the part that makes the cold) for different uses, such as a Freezer or a Fridge. The downside is having enough charging capacity to keep the batteries up. The major plus over a engine driven unit is maintaining a constant temperature over the vast temperature change of engine driven. Or in other words, people let the icecream get a little too soft before they start the engine and cool it all down again

We have on our boat, two fridge units and one freezer. One fridge has a freezer box. It is one of the three way fridges and we run it on gas. Would never have bought it if I had of known it's limitations. Very VERY power hungry. 17A on 12V DC and that is continuous as they do not cycle. 330g of gas/day on LPG. That unit is about to be removed from the boat (if anyone might be interested in it). The freezer is a front opening unit, bought from the Wharehouse for $199. I unscrewed the compressor and turned the Freezer on it's back and lowered it into a seating area, making it a chest freezer, then fitted the compressor up the correct way. I found after awhile, that extra insulation was required underneath, or on it's back as the cold was going right through and freezing the back panel. The cooling is done via the sides of these, and I have always wondered how inefficient it maybe due to some of that heat going back through the sides into the Freezer. But it was cheap and works for now and seems to be reasonably efficient.

[sealegs 0]

so wheels, what did you do about keeping the condenser of the warehouse "chest " freezer cool? assuming the condenser was on the back of the unit as well and now would be at the bottom.

[wheels 543]

That was what I was referring to about the side panels getting hot. They fit the condensers inside the side panels and so you need to allow plenty of ventilation around those sides. And thus the comment about me wondering how much of that heat gets back into the Freezer through the insulation.The insulation is not that thick on the things. Once I tipped it on it's back, the Cold went right through and actually created ice as well as a lot of condensation underneath. So if it can do that, it must allow heat to transfer through the sides. I guess that's why Chinese Fridge/freezers are cheap and not as efficient as more expensive units. It's done us OK so far, but I also expect I could do better if I build a better Freezer box one day.

[sealegs 0]

That was what I was referring to about the side panels getting hot. They fit the condensers inside the side panels and so you need to allow plenty of ventilation around those sides. And thus the comment about me wondering how much of that heat gets back into the Freezer through the insulation.The insulation is not that thick on the things. Once I tipped it on it's back, the Cold went right through and actually created ice as well as a lot of condensation underneath. So if it can do that, it must allow heat to transfer through the sides. I guess that's why Chinese Fridge/freezers are cheap and not as efficient as more expensive units. It's done us OK so far, but I also expect I could do better if I build a better Freezer box one day.

 

Ok got it. It really amazes me how manufacturers can provide a product that defies common sense in terms of use and efficiency. Surely the designer must have known the condenser heat will transfer inside the unit if he puts it inside the wall without suitable insulation to prevent said heat transfer to the inside. So having said that I presume the thermostat switches the unit compressor on more often than it should as a result?

 

I suppose placing thicker insulation inside the cooling section will rectify that but minimise your cooling space at the same time ..you just cant win without losing something valuable aye? I guess it boils down to what conditions of cooling you're prepared to live with...

 

Thanks for info wheels. It gives me something to consider as opposed to more expensive option from fridgetech.co.nz and ozefridge discussed HERE

[wheels 543]

I suppose placing thicker insulation inside the cooling section will rectify that but minimise your cooling space at the same time

First mistake I made was insulating the sides. That was when I found out the heat was dissipated through the sides. I then figured I could remove the panels and slip more insulation in. But I found it virtually impossible to remove the side panels. So I had to just leave the gap instead. And yes you are right, the result of poor insulation will be more cycling.

To give you an idea, I have just rebuilt the fridge box. I have removed the old 25mm Polystyrene insulation and used 50mm of rigid foam, which has a higher R rating over the Polystyrene. The box is vastly bigger and the cooling time and cycling has halved.

First 3 pics are after old box was removed. The white thing sticking up our of the floor is the cooling unit.

[MOTORBOAT 0]

I have a tropicool unit that i built into the side of a polystyrene/fibreglass chillibin that i made, capacity 90Lt. have had it for about 1.5 years now.

 

it is the absolute bees knees, disapointing to hear some people haven't had a good experience with them, i highly rate our one, consumes 1.7A on economy and 6A on boost mood. i would buy one again in a second.

 

[wheels 543]

This is the inner lining. A pig of a material to work with when on a boat with little workspace.

The third pic is bracing to stop the lining from collapsing from the foam pressure as it expands. It also shows the outer lining which is white prefinish ply.

[wheels 543]

And finished off. Well, not quite in the pics. It is now though.

[sealegs 0]

nice job wheels. So where did you put this one's condenser ( how is condenser being kept cool ) & what inside cooling temperature are you obtaining now?

[sealegs 0]

I have a tropicool unit that i built into the side of a polystyrene/fibreglass chillibin that i made, capacity 90Lt. have had it for about 1.5 years now.

 

it is the absolute bees knees, disapointing to hear some people haven't had a good experience with them, i highly rate our one, consumes 1.7A on economy and 6A on boost mood. i would buy one again in a second.

 

do you use yours as a fridge only MB? what temperature do you get & what type of food items do you use it for? that is frozen or non frozen