Danfoss BD35/Frigoboat problem

[onestepcsy37]

real world experience.

my adler barbour bd50 air cooled has been working for ten years. extra fan over the compressor/control module, as per richard kollman. input air is from the cabin, output heat goes straight in to the engine room. never a single problem after the initial startup.

my neighbor has it all over me. his air cooled waeco bd35 ran for 15 years until it finally rusted apart last year.

[SV THIRD DAY]

Originally Posted by onestepcsy37

s/v third day - a question. not trying to start a fight or a rant here. just a question.

i looked at your cool blue webpage. the system appears to be the typical danfoss unit with compressor, control module, fan, etc. there is a holding plate. there is tubing to connect the two. so what makes it cost $2950?

a similar adler barbour unit with evaporator costs less than half that, iirc.

remember, i'm not getting into the hot discussion presently going on; would just like to know what makes the cool blue so expensive....

Happy to answer and I will try to keep this post from getting too deep in the technical weeds. Just ping me if you want/need more info.

First, we are not using the Danfoss compressor. When Danfoss moved their compressor production from Germany to China we bailed. CoolBlue compressors are made in Spain and have fewer warranty issues especially with the electronic control unit. In fact, the entire CoolBlue system isn't imported by the container load from China, but assembled and tested here in the USA...some care about that....some don't and of course that adds to the price somewhat. But, it's also a big part of why the CoolBlue has a standard 5yr warranty compared to 1yr on other systems.

Much of the CoolBlue increased cost comes from the systems design in trying to be the most energy efficient as possible, compared to an easy to mass produce unit targeting a larger price point conscious market segment.

I won't walk through all the differences and make this post crazy long but will just take one for now Take the aluminum evaporator plates compared to our holding plates for example.
You can buy rolled aluminum evaporators similar to the AB Cold Machine online for $198 (www.rparts.com). In comparison, the raw material costs for our fin-tube holding plate with thermally adjusting expansion valve is much more than that $198 retail evaporator price. Sure we could remove the high surface area fin-tube evaporator that we have custom made in Texas from inside our holding plate and just coil 12ft or so of copper tube inside the holding plate and save production costs. That production cost savings would of course come at a price to the efficiency of the system. Without the custom made evaporators inside, our holding plates would be like many other holding plates in the industry that have issues with efficient heat transfer from the refrigerant to the eutectic solution. (of course we have done the test and know) The dings you often hear about holding plate systems not properly freezing the eutectic solution and thus being inefficient isn’t true with our holding plates. Not because we are better engineers or smarter than the others, heck this isn’t rocket science after all, it is just simple thermodynamics and heat transfer. What makes us more expensive is that we don’t chose to save the production cost and offer a less expensive product with a decreased efficiency. Now do we tout this holding plate design on our website or sales literature? No, not really. Just how much technical detail do you give out before people’s eyes glaze over when all the client really cares about is having ice cream and cold beer in the tropics, while using dramatically less daily power than the other systems on the market.

Technautics has long debated offering a cheaper unit comparable in price and performance to the AB Cold Machine, and we actually have several such R&D units sitting on the shelf along with the data ready to go. But to be frank, the reason the less expensive and less efficient system is still on the shelf rather than in production comes down to a company decision of Focus and Time. In 2013 Technautics sold on average 18.3 CoolBlue systems per month (219 for the year) and another 64 stand alone CoolBlue condensing units to upgrade older engine driven or 110v systems to 12v. Now that's nothing in comparison to the AB Cold Machine type systems sold in 2013, but to us...well that kept us pretty damn busy. In order to continue our 7 day a week customer service/technical support (the only such thing in the industry) and still have some type of lives outside of work, we simply can’t try to be everything to everyone. Until my son gets old enough to join the business and decides to grow things to the next level (while I am floating aboard in Mexico), Technautics will focus on what’s built our reputation for the last 45 years: Energy Efficiency, Reliability, and Customer Service.

Customers looking to save a bit on the price can buy at a boat show (or tell me we talked at the show when ordering) because our standard Boat Show Special for years has always been to sell at dealer pricing (15% or $450 off list)...which may explain the 17 units we sold at the 5 day boat show">Miami Boat Show two weeks ago...Ugg...not I have to get them all shipped!

[onestepcsy37]

svthirdday said -

"we are not using the Danfoss compressor. When Danfoss moved their compressor production from Germany to China we bailed."

that's a kick in the groin; hope my adler barbour outlives me - don't think i'd want to buy another danfoss compressor...

[CarlF]

I went to check the "china" story. It's not only true but Danfoss was then bought by a German company in 2011 and changed its name to Secop.

They do have a nifty video on their website of compressors (a lot of compressors) being built:

Production

[Neptune's Gear]

Quote from Richard
"Using adequate air as the only cooling medium for a refrigeration system powered by a Danfoss BD compressor will not allow compressor to fail as long as refrigerant remains pure. Any use of water as a cooling medium will cause Danfoss BD compressors to fail. Can anyone debate this with quantified data per 1,000 hours?"

Sorry Richard, that is absolutely misleading and inaccurate.

Which ever medium you choose to cool the heat exchanger is irrelevant. The cooling air or water is not mixed with the refrigerant, and has no effect on the compressor. The only issue could be if the heat exchanger failed to contain the refrigerant. This would cause a failure of the system in both cases.
What is important is how efficiently the returning hot refrigerant is cooled, and how much it is cooled. Water does this more effectively than air. This is an engineering fact.

By the way - my own unit has now been running for over 3 years without being switched off - what's that - over 26,000 hours - considerably more than your 1000 hours.

I can see that you are fixed in your ways and ideas. That's fine, but people have to choose what they think sounds correct. That is all I have to say. Flame away if you must, but try to tell people the facts.

[colemj]

The water-cooled Danfoss compressors have a known history of failure due to corrosion of the heat exchanger. Is yours a Danfoss compressor?

While water is a more effective cooling medium than air, you missed the point that it does not matter for a properly installed compressor. It does not matter how much the refrigerant is cooled - only that it is cooled to a specific temperature. Water or air - it doesn't matter. Your energy efficiency is not determined by that (assuming a proper installation).

Mark

[SV THIRD DAY]

I should jump in quickly and comment about Danfoss before a false impression gets going. I did not say or intend to say that Danfoss makes a bad compressor JUST because they moved production to China. Or that the Danfoss compressor is not good! So let me clarify a bit before Danfoss takes a black eye that I didn't intend.

Shortly after the Germany to China compressor build change happened we received our first pallet shippment of Danfoss compressors built in China and it was a complete disaster! Thank goodness every single CoolBlue goes in a test box before it ships to the customer (again more labor cost, but it adds to quality). We started finding an incredible number of out of the box compressors were crap...dead...kaput. Some didn't run at all, while others had Amp usage data all over the park. We had orders to fill and a pallet of compressors we didn't trust to send out to clients. Fortunately, Randy had already been testing the performance of the compressors from Spain and was able to air freight in replacements out from Barcelona. The results were great, warranty claims went to record lows, and we decided to not go back to Danfoss. We were perfectly happy with our new supplier that rushed in to save us in a time of need.

Let me say this in bold so no one gets the wrong idea, or starts spreading bogus rumos attributed to me that Danfoss is making crap stuff in China. I believe that without a doubt Danfoss overcame the "Germany to China transition" and is now making good quality units. In fact, there has been times in the last few years when due to shipping/customs delays we have built some CoolBlue's using the Danfoss and they have done well.

Originally Posted by colemj

The water-cooled Danfoss compressors have a known history of failure due to corrosion of the heat exchanger. Is yours a Danfoss compressor?

While water is a more effective cooling medium than air, you missed the point that it does not matter for a properly installed compressor. It does not matter how much the refrigerant is cooled - only that it is cooled to a specific temperature. Water or air - it doesn't matter. Your energy efficiency is not determined by that (assuming a proper installation).

Mark

I think you nailed it Mark.
As long as the system is capable of cooling the refrigerant down to the specific levels you can use water, air, rum, or peanut butter. The cooling medium doesn't matter as long as the correct refrigerant temperatures are reached. Pumping peanut butter will of course use more energy than pumping, water, or air around the loop. It's been Technautics approach that staying away from using sea water as a medium has advantages (sea water is evil) AS LONG AS you then design your air cooled system to be capable of tropical temps and heat loads.

One more quickie to add after rereading the post to corect my horble speling. I use the term "We" to refer to Technautics since I'm the owner, but that was the Royal we and I should have said Randy. I wasn't around when some of these things were going down...heck....I wasn't even BORN YET when Randy founded Technautics back in 1968...ha ha ha.

[Celestialsailor]

Originally Posted by Neptune's Gear

Quote from Richard
"Using adequate air as the only cooling medium for a refrigeration system powered by a Danfoss BD compressor will not allow compressor to fail as long as refrigerant remains pure. Any use of water as a cooling medium will cause Danfoss BD compressors to fail. Can anyone debate this with quantified data per 1,000 hours?"

Sorry Richard, that is absolutely misleading and inaccurate.

Which ever medium you choose to cool the heat exchanger is irrelevant. The cooling air or water is not mixed with the refrigerant, and has no effect on the compressor. The only issue could be if the heat exchanger failed to contain the refrigerant. This would cause a failure of the system in both cases.
What is important is how efficiently the returning hot refrigerant is cooled, and how much it is cooled. Water does this more effectively than air. This is an engineering fact.

By the way - my own unit has now been running for over 3 years without being switched off - what's that - over 26,000 hours - considerably more than your 1000 hours.

I can see that you are fixed in your ways and ideas. That's fine, but people have to choose what they think sounds correct. That is all I have to say. Flame away if you must, but try to tell people the facts.

Speaking of absolutely misleading and inaccurate. All you're stating is the switch on the panel is on. Your unit cycles, unless you want us to believe it never cycles off. Their are people that have already stated their air cooled units are over 15 years old.
Regarding the water cooled units, if the refrigerant coil is immersed in salt water or tank water, any breach of the line would contaminate the system. This is an engineering fact.
I do not believe anyone is flaming away here. In fact, most people have units and are only stating how their units are working. You seem to be pushing a product.

[Richard Kollmann]

I believe people posting on this thread believe in what they write and yes there are a few that try to push their products and there is no harm in this.. Without creative advertising there would be only one source for pleasure boat refrigeration. Unfortunately reliability analysis of these icebox conversion refrigeration units in not covered by job shop manufactures leaving reliability to attrition like a kitchen appliance.

Celestial sailor, and maybe others did not understand the question I wrote, “ Any use of water as a cooling medium will cause Danfoss BD compressors to fail. Can anyone debate this with quantified data per 1,000 hours?"
The answer is NO, because it would take hundreds of thousands of operating hours aggregated from many systems . The other problem is there are no to boats boxes the same and in mobile refrigeration there are too many variables. If you want good information on a boat refrigeration unit pay attention to a live aboard blue water boaters comments with more than five years experience with the same refrigeration system.

Rich Boren of Technautics experience with Danfoss was interesting and the current Spanish GD30 compressor somewhat equal to a Danfoss BD 35 is a disappointing change. That compressor has had a bad history in the past and I believe Technautics is the only one using it in the US. In the past when I was contacted for advice on this Spanish DC compressor it was impossible to help because no one has an understanding of its electronics or replacement parts so they have always been considered as expendables. When a boater spends a great deal of money on a refrigeration system he needs local repair ability and parts available where ever boat is in the world.

I can not except Technautics explanation for the ridiculous price of a CoolBlue system, twice or three time the cost of equal available units. I just checked on line an Adler Barbour with larger BD50 compressor system on line from West Marine $1259 with Bin evaporator.
I believe I was the first one in this country to power and market a line a holding plate with a Danfoss BD compressor/condensing units. The air cooled compressor condensing unit sold for $350 and plate about the same size as CoolBlue’s plate was $200. I do believe the CoolBlue is efficient in the right application but this is not to say that many other companies have units as equally efficient in the right application as long as equal system has a variable speed BD35 compressor. It is also possible that a BD35 system and standard roll bond evaporator like Frigoboat’s air cooled Capri or Nova Cold unit installed in the same box under same conditions might be more efficient than Techanics holding plate system. It seem people believe holding plates are efficient with a compressor producing 200 to 500 btu per hour. Holding plates are designed to store surplus energy and a Very small compressor produces no surplus energy without an alternative energy source wind or solar or shore power plugged in. A Btu of energy is can change the temperature of one pound of water one degree F. To change liquid water to ice it takes 144 Btu per pound of solution. After eutectic solution is phase changed to a solid its temperature can be lowered further but energy storage is limited to ½ Btu per degree per pound. The reason a holding plate can be less efficient than a standard evaporator is the compressor running time required to freeze the solution each cycle is too long. If you increase compressor speed to compensate for added running time the COP efficiency is reduced as much as 50%.

The most efficient holding plates for boats were made by Dole and used mainly by Crosby and Grunert refrigeration these plates used mechanically bonded evaporator plate coils and brine solution. They are still in business today and have made plates for boat owners.

[SV THIRD DAY]

Originally Posted by Richard Kollmann

That compressor has had a bad history in the past and I believe Technautics is the only one using it in the US. In the past when I was contacted for advice on this Spanish DC compressor it was impossible to help because no one has an understanding of its electronics or replacement parts so they have always been considered as expendables. When a boater spends a great deal of money on a refrigeration system he needs local repair ability and parts available where ever boat is in the world.

With thousands of CoolBlue units sold with the Spanish compressor, while offering the best warranty (5 Yr) in the Business, I would sure love to know where this "bad history" came from especially if, as Richard points out, "Technautics is the only one using it in the US?". Our Warranty claim rate certainly doesn't tell that story...nor do our CoolBlue customers.

As for CoolBlue repair parts presumably not being available around the world. There is not a single part on our CoolBlue system that can not be repaired or replaced locally just like the Danfoss unit. I have no idea where/how this false impression/rumor got started. If a Hermetically sealed compressor (Danfoss or Cubigel) dies (you have a better chance of winning the lottery) then they are non-repairable and simply get replaced. You can get replacements for the CoolBlue electronic modules world wide just as easily as the Danfoss electronic controler along with any other of the system components.

We can continue this friendly back and forth until the perverbial sea cows come home or my partner that actually does the building of our water makers and CoolBlue units finds out I'm "messing around" on the internet forums while he scrambles to fill orders. I respect Richard's experience and opinions. I just have a pile client feedback and test data going back 45 years comparing the CoolBlue to other systems, along with the ongoing test box trials that makes me feel pretty comfortable with the CoolBlue Systems. Rather than shy away from this type of discussion, I wish more marine gear manufacturers would step up and openly discuss their products. It would have helped me a great deal when I was outfitting our boat to first head to Mexico back in 2007.

[Boatguy30]

Technautics claims that the TX valve makes up for the phase change inefficiency and therefore maximizing the COP in all box temps.

As I say, it blew me away when they were going to sell me a special 20 % more efficient unit than the one they were selling to West Marine. I guess maybe they were leaving out the expensive coils in the WM units, but no explanation was given. Can you imagine going to the Toyota website and them offering you a more efficient Prius than the local dealer was selling at the same price?

I have been exceedingly happy with the nova kool units. I just got a custom 3 plate evaporator to redo an older system. The cost was $260 delivered. I guess they did it mainly to be nice as I can easily have seen the labor alone at that at a place like Rich Beers.

[SV THIRD DAY]

Originally Posted by Boatguy30

As I say, it blew me away when they were going to sell me a special 20 % more efficient unit than the one they were selling to West Marine.

Maybe Randy was saying he would sell direct for 20% less cost than West Marine, not 20% more efficient. I know Randy stopped doing business with WM becasue it would take them 30 days just to get an order out of their system and was a huge headache to deal with. That would make sense...but not having asked Randy about it, that's my only guess. Glad to hear you are happy with your Nova Cool, the two we have been running here and testing for years has been doing well also, it's a good unit.

[lancelot9898]

It's been decades since my undergraduate days in thermodynamics, but the info presented by Kollmann in this thread rings true. There is one other person that I respect very much for his technical expertise and that is Cleve the owner of Seafrost. He was straightforward and understood the engineering principles involved without a lot of BS that so many others seem to promote.