Need New Fridge - Advise Me, Please

[downunder]

tom,

I would be a bit nervous with an aircooled condenser in tropics unless reassured by an expert fridge mechanic.

cheers

[Pblais]

I would be a bit nervous with an aircooled condenser in tropics unless reassured by an expert fridge mechanic.

Richard Kollmann explains the issues above quite well. It's not just a technology question. If it were that easy we would never need a Fridge thread here at CF. You can make things work if you can work all the numbers not just the pretty ones. It isn't just a purchase decision. You are stuck with the box that you have and making the box better is often the road to success. Too much insulation has never been a totally wrong idea.

[downunder]

Originally Posted by Pblais

Richard Kollmann explains the issues above quite well. It's not just a technology question. If it were that easy we would never need a Fridge thread here at CF. You can make things work if you can work all the numbers not just the pretty ones. It isn't just a purchase decision. You are stuck with the box that you have and making the box better is often the road to success. Too much insulation has never been a totally wrong idea.

Pblias

Exactly the point I was making to Tom from someone following his blog on his travels through the tropics where refrigeration decisions and air temperatures are regularly 30C or above and are even more critical.

I have no doubt given all the paramaters Richard Kollman's suggestions and advise are best practise.

[Wand]

Throw it out; you don't need a fridge. All these new fangled gadgets require so many add-ons; more power, more strife, more cost. It was okay for sailors just a few decades ago, and it's still the same ocean...

[Hudson Force]

Originally Posted by At sea

Throw it out; you don't need a fridge. All these new fangled gadgets require so many add-ons; more power, more strife, more cost. It was okay for sailors just a few decades ago, and it's still the same ocean...

I like this attitude! I would accept the challege to throw it out! I've been blessed with a vulgar palette that would allow me to be satisfied with canned and dehydrated foods and warm drinks, but no such luck. I have to give up the simple life for my wife's pleasure. So, I'm stuck with the frozen lobsters and steaks waiting for their opportunity and ice in my drinks. Everything's negotiable in a successful marriage!

[Pblais]

Everything's negotiable in a successful marriage!

Compromise at Sea:

Rule of the Admiralty: The Admiral knows when she is right (and when you're not).

Santa Claus can't even do that!

There is much to be said for eating and drinking well! You can do it on a budget and with a small fridge. It's about what's important.

[cantxsailor]

I still think my Engel is the best piece of machinery I've ever owned. It draws <3amps even in the 95+ summer heat here on Galveston Bay and my beer is a lovely cold 29*. Mine is small enough to yard it out of the boat for a road trip. They come in a number of sizes to suit almost anybodies taste, they are almost silent, and with only one moving part nothing to break. Give them a look................m

[Wand]

Originally Posted by CaptForce

I have to give up the simple life for my wife's pleasure. So, I'm stuck with the frozen lobsters and steaks waiting for their opportunity and ice in my drinks. Everything's negotiable in a successful marriage!

Originally Posted by Pblais

Compromise at Sea:Rule of the Admiralty: The Admiral knows when she is right (and when you're not). Santa Claus can't even do that! There is much to be said for eating and drinking well!

I got smart with a kiwi bride; the zany concept of refridgeration on boats never caught on down there... The happy trade-off is: lap of luxury at home, primitive aboard.

PS: It's true I get to go out alone a lot...

[Richard Kollmann]

I would be a bit nervous with an aircooled condenser in tropics unless reassured by an expert fridge mechanic.

cheers downunder

ANSWER:

Downunder, is on the right tack but a refrigeration engineering group would be the place to go for advice on importance of correct amount of condenser cooling. I do not know of any qualified refrigeration engineer that would recommend water cooling condensers smaller than 1/4 HP. You will not even find information on water cooling in Danfoss’s application engineering data sheets. Mobile systems that use water cooling will need devices to control the correct high and low pressures. Danfoss engineering specs say at test condition performance condenser was at 130 degrees. With tropical seawater temp at 90 degrees even at midnight and water temps of 65 or below in northern Latitudes how could water cooling deliver best refrigeration performance on a small system without a way to control water temperature exchange?

The best source for importance of condenser cooling temperature control and how too much or too little will affect your choice of mobile boat refrigeration Search REFRIGERATION ENGINEERING.com Forum, or post a question. There are true design engineers on that forum along with books on controlling condenser outlet temperature pressure.

[jkleins]

Originally Posted by At sea

PS: It's true I get to go out alone a lot...

We suspected as much.

[TOM]

We have decided on a Air cooled Isotherm with a large evaporator plate that we will have bent in order to give us a small freezer as well as a fridge. Since our fridge has broken we have been buying ice and have gotten very use to having it with our gin & tonic , {Bombay Saphire of course} so the abilaty to make ice will be nice.
We are useing Siam Cooling in Phuket who have come highly recomended and seem to do most of the air cond/ fridge work here. Its interesting that the professioinals seem to almost always recomend Air cooling {as long as it is correctly installed } over water cooled units ,ease of instalation and reliability been the main factors. For $1450 AUD he will supply the Compressor and evaporator plate ,bend the plate to our requierments come to the boat and give us advise on where and how to install. Pretty good value i thought.
www.byamee.com

[capngeo]

Just curious.... why isn't absorption refrigeration ever used on a boat? there are ZERO moving parts, they draw no electricity, and have been used for 75 years in off grid applications. I have a RV with an absorption fridge, that has been running 24/7 for 5 years now. Mine is a 3-way unit; 12VDC, 120VAC, and propane.

I know the inherent dangers of propane aboard, but a diesel or butane flame could work well if engineered properly. The above notwithstanding, I (as do many) have a propane stove aboard and hardly ever give its use a thought. Perhaps one of the refrigeration experts would care to opine?

My current "refrigeration" is an ice box with a small evaporator powered by a 120VAC compressor while dockside or through the inverter...I cobbled the whole thing together from an old countertop icemaker (for the compressor and condenser), and my own fabrication of a holding plate. I don't use it much underway. I have a dockside chest freezer which supplies me with a lot of those "blue ice" packs frozen solid.... I get about 7 days out of a load of them and maintain >40°.

I won't mess with my current design until it either fails or I upgrade boats; when I do, I will take a serious look at absorption. The only issue I see would be operation while heeled. Perhaps a gimbal of sorts?

[Hudson Force]

Originally Posted by At sea

I got smart with a kiwi bride; the zany concept of refridgeration on boats never caught on down there... The happy trade-off is: lap of luxury at home, primitive aboard.

PS: It's true I get to go out alone a lot...

Luxury at home and primative aboard is not an option when your home is aboard. Sometimes you have to make a choice!

[Maren]

Originally Posted by GordMay

Stuff like this is only part of why we call Richard the Marine Refrigeration Guru!

I was thinking the same thing. Well, that's not totally true. Actually, I was thinking, "I bet Mr Kollmann knows the answer to this" followed by, "I really need to order those two books of his."