12v refrigeration system for 11 sqft

[wscotterwin]

Rich, do the Cool Blues come in all three sizes? BD35, BD50, BD80?

[a64pilot]

Originally Posted by wscotterwin

Rich, do the Cool Blues come in all three sizes? BD35, BD50, BD80?

He isn’t on this thread, best to contact him via phone.
Number at bottom of page
My bd80 was a special build and I believe may require dual cold plates, plus except maybe for the 80. I don’t think they have used BD compressors for quite sometime, I believe they use Cubigel.
http://www.cruiserowaterandpower.com/Home_Page.html

[Maka]

Facinating

[Uncle Bob]

Originally Posted by wscotterwin

Rich, do the Cool Blues come in all three sizes? BD35, BD50, BD80?

Rich Boren of Cool Blue manufacturers efficient,extremely effective refrigeration systems, Richard Kollman does not.

[a64pilot]

Originally Posted by Uncle Bob

Rich Boren of Cool Blue manufacturers efficient,extremely effective refrigeration systems, Richard Kollman does not.

He may not any longer, but to say he doesn’t isn’t I don’t think telling the whole truth.
Richard is I would estimate one of the pioneers of marine refrigeration, and has forgotten more than I’ll ever know for example.
I listen to what he has to say, cause he knows what he is talking about, it may not be what you want to hear, but it comes from experience.
If you want a larger refrigeration system, best be prepared to feed it, cause it is a hungry beast. It’s just simply a matter of scale is all.
Remember TANSTAAFL.
I don’t remember there being a second T, but there has to be doesn’t there?

[Richard Kollmann]

Originally Posted by Uncle Bob

Rich Boren of Cool Blue manufacturers efficient,extremely effective refrigeration systems, Richard Kollman does not.

Let me correct this misconception of what I believe. Randy's design for the Cool Blue refrigeration of today dates back more than 25 years. His true break through in in the Cool Blue came about with the change of fixed speed to variable speed improved performance compressors from Danfoss. Rich Boren now continues manufacturing the only energy efficient ice box conversion refrigeration system for boats with small insulated boxes. The success of the Cool Blue's design is simply refrigerant TXV flow control and a BD35 capacity compressor running much longer at its most efficient speed results in consuming for less energy.

Uncle Bob, I have always recommended the Cool Blue machine as there is currently no other unit in the world that can compete with the reliability and performance of the Cool Blue air cold machine in the right size insulated box that I am aware of.

[Uncle Bob]

Originally Posted by Richard Kollmann

Let me correct this misconception of what I believe. Randy's design for the Cool Blue refrigeration of today dates back more than 25 years. His true break through in in the Cool Blue came about with the change of fixed speed to variable speed improved performance compressors from Danfoss. Rich Boren now continues manufacturing the only energy efficient ice box conversion refrigeration system for boats with small insulated boxes. The success of the Cool Blue's design is simply refrigerant TXV flow control and a BD35 capacity compressor running much longer at its most efficient speed results in consuming for less energy.

Uncle Bob, I have always recommended the Cool Blue machine as there is currently no other unit in the world that can compete with the reliability and performance of the Cool Blue air cold machine in the right size insulated box that I am aware of.

Richard, thank you for confirming my earlier post, but I think it a little disappointing that you have dismissed out of hand every other manufacturer in the world. Surely to do so does nothing for the industry as a whole.

[Uncle Bob]

Originally Posted by a64pilot

He may not any longer, but to say he doesn’t isn’t I don’t think telling the whole truth.
Richard is I would estimate one of the pioneers of marine refrigeration, and has forgotten more than I’ll ever know for example.
I listen to what he has to say, cause he knows what he is talking about, it may not be what you want to hear, but it comes from experience.
If you want a larger refrigeration system, best be prepared to feed it, cause it is a hungry beast. It’s just simply a matter of scale is all.
Remember TANSTAAFL.
I don’t remember there being a second T, but there has to be doesn’t there?

Hi, at no point did I question Richards contribution to the development of the refrigeration side of boating, no doubt we owe a great deal for this, just as we owe to the developers in other industries such as the automotive, aviation, electrical etc. As in all industries progress is made and developments lead to greater efficiencies and performance, some great others small. To deny this is to ignore reality.

As far as small refrigeration is concerned I believe that by far the greatest step forward has been the development of inexpensive solar power systems, enabling the operation of small systems 24 hrs per day, without the need to run generators or engine driven compressors. The further development of electronics that enable these systems to be run when power is abundant and to switch off when it isn't is I believe a another step forward.

If in any of these industries the original pioneers had blindly said it can't be further developed, where would we be today? still riding around in model T fords?
Anyhow, rant over, have a nice day.

[a64pilot]

Issue is that pretty much we are exactly where we were 25 years ago, unfortunately since the variable speed compressor there has been no revolutionary step. Not yet.
I have a Danfoss AEO controller on my system and think it’s great, it I believe utilizes the variable speed function better than leaving it fixed speed, or trying to vary speed as a function of battery bank voltage or changing thermostat set point, I’ve tried both with very limited success.
The AEO just works, but it’s no revolutionary step.

I had hope for the Sawafugi swing compressor but apparently even though it’s a neat concept and is a simplistic compressor, it’s apparently no more efficient, or if it is it’s not by much.

Electronic controls haven’t as far as I can tell really done all that much either, we are still stuck with the greatest difference is in insulation, want a great efficient low power usage fridge? Super insulate it, and buy a simple non complex reliable simple to fix compressor system and put in it.
I mean simple thermostat, simple air cooled condenser, with a drier to prevent future issues etc.

Nothing at all wrong with a cap tube if it is matched to your box, but I’m of the opinion that a TXV system is more variable or flexible.
My point is I guess that X manufacturers system if it’s well designed meaning that the pieces parts are well matched etc, is right at the same efficiency that Y manufacturers system is if it’s well designed etc.

Be very wary of claims of any system claiming to be far more efficient than others, unfortunately that’s just not true.

Its similar in a way to Diesel engines, Volvo, Yanmar, John Deere, Cummins, Kubota etc are all right at the same efficiency, there is very little difference between all of them fuel consumption wise.

So instead of believing great claims of efficiency, be suspect of that and instead chose a system that is simple, easy to trouble shoot and repair, and comes with good customer service, same as in picking a Diesel engine cause they are all almost the same in fuel consumption.

Now hopefully tomorrow somebody will develop a tiny scroll compressor that is super efficient, I hope so, but it’s not happened yet, we are still in the 20th Century refrigeration wise, even though of course some would have us believe differently.

Now this is not to say that all systems out there are well matched components, they aren’t and if not well matched efficiency suffers.

See it sort of boils down to this, all manufacturers buy the big, technical parts, compressors etc. they may use different manufacturers, but they are all off the shelf compressors that are almost identical to the original BD design. They may make their own evaporators and maybe even condensers, the TXV if there is one and the drier etc are purchased.
So there just isn’t really an opportunity for one to be far superior to any other.

People will take offense to this as they will say that they have this or that made to their specification or maybe the programming is different in their controller etc. but unfortunately there is no clear heads and shoulder above any other winner.

[alansmith]

A64, thanks for some common sense about refrigeration.

[FlyingScot]

A64, can you share you evaporator plate sizes, low and high side pressures when the box is cold?

[Richard Kollmann]

Originally Posted by Uncle Bob

Richard, thank you for confirming my earlier post, but I think it a little disappointing that you have dismissed out of hand every other manufacturer in the world. Surely to do so does nothing for the industry as a whole.

Yes, I do dismiss areas of the world’s mobile refrigeration industry and look only at the dark side of what appears to me as a dying Ice Box Refrigeration Conversion Industry. Those manufactures and Job shops that haven’t been taken over by others have needed to diversify to more other type product lines in order to stay in business. There are many reasons why this small industry is in trouble portable and complete cabinet refrigerators are less expensive and easier to install. Marketing and business planes have gone to extremes avoiding the simple reliable maintainable refrigeration systems. Proprietary technical information and parts designed specifically for use on that particular refrigerator are a good reason to look for a better choice. Bob, look around there in Australia form Perth to Sydney these products are primarily marketed by the two acquisition multi shop marketing companies Demedic and Indel.

[ayates]

Originally Posted by a64pilot

Electronic controls haven’t as far as I can tell really done all that much either, we are still stuck with the greatest difference is in insulation, want a great efficient low power usage fridge? Super insulate it, and buy a simple non complex reliable simple to fix compressor system and put in it.

I ran a set of tests comparing an OEM thermostat with an electronic thermostat. The electronic thermostat did provide a better cool down (the compressor ran continuously), and the overall duty cycle was less (but the freezer temperature was not as low). The latter is pretty much a show stopper for the the electronic thermostat, but I also found it to be unreliable as well.


Allan.

[a64pilot]

Originally Posted by FlyingScot

A64, can you share you evaporator plate sizes, low and high side pressures when the box is cold?

Its honestly is an off the shelf Cool Blue unit just with a BD80 compressor, Rich Boren would be the one to best contact about that, the plates are two of his large size ones.
I don’t know pressures to be honest. Servicing the Cool Blue is very simple, as it’s not a capillary tube system, it’s refrigerant servicing level isn’t real critical. It can store some excess refrigerant in the drier.
So to service it from a vapor charge level, meaning no liquid refrigerant left in the system and the system off of course, it takes two full 12 oz cans, that’s it. You don’t need a chart of outside temperatures and evaporator temp etc to charge to, no watching frost lines etc, just two full cans and your done.
So therefore I’ve not put a set of gauges to it, they are in storage somewhere, I used to keep them on the boat, but my AC’s are sealed and you don’t need them for the Cool Blue.

Now twin Cool Blue units, one for the fridge and one for the freezer would have been better I’m sure, but best to ask Rich Boren about that

[Richard Kollmann]

Originally Posted by ayates

I ran a set of tests comparing an OEM thermostat with an electronic thermostat. The electronic thermostat did provide a better cool down (the compressor ran continuously), and the overall duty cycle was less (but the freezer temperature was not as low). The latter is pretty much a show stopper for the the electronic thermostat, but I also found it to be unreliable as well.


Allan.

If I am reading the middle of your graph correctly 10 compressor start ups in 2.5 hours is not really energy efficient. Three things come to my mind and any one of them could reduce daily amp-hrs consumed, Decrease compressor speed, Increase the thermostat differential OFF time, or if this is a Danfoss BD compressor change module to an AEO automatic compressor speed control module. Two compressor cycles per hour is a good number to design for assuming desired box temperature is maintainable.