Not as much to post about the past two weeks as I have been out of commission after hurting my back badly when I tripped and fell last week and aggravated the four cracked discs I have had from a nasty motorcycle accident over 25 years ago. But the spasms are lessening each day since and just a matter of time before I’m back to just the usual back ache which is my normal state. No complaints from me though as we continue to enjoy taking our time to weave our way generally north through some of the hundreds of postcard like Bahamian islands.
When I left off in the last post we were in Red Cut Cay and after a few days there we continued up and anchored at Black Point then on to Allen’s Cay and then a very neat fully enclosed very tiny little bay on Royal Island as seen here on our chart plotter. This will give you a better perspective on how small the entrance was and if you click on the photo I have circled in RED the two short pieces of white PVC pipe that marked each side. Captain Christine guided us through as she put the entrance in our wake and …… …… I soon had the anchor down into the sandy bottom 2.5m/8ft below and we were soon enjoying our very own little anchorage with wine up in the SkyBridge. THIS is why we worked on the design so hard with Dennis to have the least draft possible; 1.3m/4.4 ft After Royal Island we made our way over to Lynyard Cay where we anchored for four days and had a chance to meet up with some sailing friends Mark & Shawnae who were anchored nearby on their latest boat s/v Big Sky Blue Waters (they hail from Montana). Difficult to show on maps as most of these spots are too small to show up but you can get a rough idea of our route and anchorages along the way. We are now anchored up near the north end of Great Abaco Island just off of Coopers Town. There is a storm front coming through this weekend with winds out of the West and South rather than the usual Easterlies so we’ll wait out here for that to pass and then make our way West as we get ready to jump off and cross over to West Palm Beach area in Florida in the next week or so.
That catches you up on our most recent travels and anchorages and now I thought that something a bit different might be of interest to many of you. Read on to see what you think and let me know your thoughts with comments in the “join the discussion” box at the end please.
Year in Review: Top Features We Like Most and Least on Möbius
Hard to believe but we started writing this Mobius.World blog back in March 2018 so we’ve just passed the five year mark for that and the primary motivation for creating and writing the 262 posts since then has been the hope that sharing our experiences here provides a good way for us to “pay it forward” for all the other people who went before us and shared their experiences from which we learned SO much. In keeping with that hope, as the calendar turns over to May (how did THAT happen so fast??) we have been actively cruising Möbius for one year now. Also on the hard to believe list is that our log book shows that we have just ticked over 7300 nautical miles (8400 miles/13,520 Kilometers) and most of that in just the last six months since leaving Turkey at the end of October. Last year we were in and out of a number of marinas so we have been through our share of Med mooring, docking, fueling up and the like. This year we’ve been on anchor every night for the past four months in quite a variety of conditions, bottoms and weather. We’ve done everything from short day trips, lots of overnight passages and some longer ones such as our trans Atlantic crossing of 14 days. With these cumulative experiences I thought now would be a good time to reflect on what we have learned over the past year about what is working out best for us as well as what has not worked so well and we would change or do differently to make Möbius even better. I will write this up as two blog posts grouping what’s worked best into one and then a second with what changes we would make to follow. In my experience I have found that first hand experience from others has proven to be the best and most useful for making my decisions and so I hope these twin posts will do likewise for some of you.
A few caveats before I go any further:
All of the points I’ll be covering are simply what has worked so well or not for us and our use cases with no suggestion that these would be best for other owners, boats and use cases.
There is no implied order or ranking of these items, simply a list.
Any mention of specific products is done for clarity only, these are not endorsements and we have no sponsors or affiliations with any of the products mentioned.
In the years of posts here on this blog, I have provided lots of detailed coverage, too much perhaps, of each of these items during the build so in this posting I will just be listing the reasons why each item is on the list. If you are interested in more details you can refer to these previous posts and I’ll provide links to some of these.
OK, with that out of the way, let’s jump right into our top favorite features on Möbius.
Anchor system
Starting up at the Bow, our whole anchoring system has proven to be eXtremely strong, reliable and easy to use and has perhaps contributes more than any other system to our SWAN factor that enable us to Sleep Well At Night in every anchorage in all conditions. The “SideWinder” mounting of the anchor off the Port side of the Bow which Dennis and I designed, has proven to be a great setup eliminating the anchor and roller assembly from sticking out over 1m at docks and keeps it very securely pressed against the hull in pounding seas with nary a sound or any movement. The primary components of our Anchoring System are
110Kg/242lb Rocna anchor
100m/330ft of Galvanized DS40 13mm chain
Maxwell windlass VWC4000 w/Maxwell controls at both helms and wired remote in forepeak
Lewmar Deluxe Heavy Duty Chain Stopper 13mm chain
Lewmar EVO 55 Self-Tailing Winch for kedging The chain all stows inside of a round aluminium chain bin inside the forepeak which has worked out eXtremely well as there is no “castling” of the chain as it is stowed. and any anchor mud and muck that gets in there is easily flushed out through the drain in the bottom that exits out the side of the hull just above the waterline.
Once the anchor is set we attach a 25mm/1″ nylon snubber line using a loop of Dyneema with a slip knot that goes through one link on the chain. This takes seconds to attach or remove and the snubber from the chain and absorbs of any shock loads on the anchor chain and eliminates any chain noise into the boat. Letting the chain out until the snubber is taking all the tension the line comes up through the large round “nose cone” in the very front of the Bow and ties to the Samson post. Leading the snubber line through the center of the Bow reduces side to side swinging at anchor and the hyperbolic curve machined on the inside of the sold AL snubber cone prevents chaffing of the line which still shows no sign of chaffing after over 150 nights at anchor so far. The large degree of forward slope of the anchor deck also worked out great making it easy to hose down with all the debris draining out the nose cone back into the sea. All together this is a super dependable and easy to deploy/retrieve anchor system that sets first time every time and resets immediately on severe wind shifts. Depends on water depth of course but typically we have about 30m/100ft of 13mm anchor chain out which adds an additional 120kg/265lbs to the 110kg/242lbs of anchor on the bottom so we SWAN very well every night and is definitely one of our favorite systems!
Foul Release silicone bottom paint
Our last minute decision to go with silicone based “Foul Release” bottom paint instead of CopperCoat has turned out to be one of THE best decisions we made. This Foul Release type of bottom paint never ceases to amaze me with how it prevents almost anything from growing on it and what might be there after months of sitting still comes off completely with a simple wipe with a sponge or cloth to bring it back to like new. We used the International version called InterSleek 1100SR but several other manufacturers such as Hempel “Silic One” are also available. This paint has been in the water for over two years now and it still cleans up completely with just a sponge or cloth if we’ve been sitting at anchor for a long time and currently shows no sign of wear or age. It is supposed to be good for 5-7+ years and so far looks like it will achieve that easily which would be a HUGE benefit in terms of efficient hull speeds and no costly annual haul outs. I can’t say for sure but I think that having such clean and slippery silicone hull surface contributes to our overall hull efficiency, speed and great fuel burn rates. What’s not to like??!!
Open and Accessible system installation
All of the system components, wiring and plumbing were given dedicated locations with completely open access. This reduced the time for initial installation during the build but more importantly continues to put a smile on my face every time I need to do any work or maintenance on any of the systems as everything is easy to access and mounted at a just right height for working on. Here in the Basement for example you can see how all the components such as all the 14 MPPT controllers on the Left and the three 240V Victron Multiplus inverter/chargers on the Right, are all mounted such that when I’m kneeling or sitting in front of them they are at the just right height right in front of you to see and work on. Same story back in the Workshop area where all the major components on the Right such as the DC Distribution box, Kabola diesel boiler, watermaker and AirCon chiller system are mounted on top of the shelves to put them at just right height as well. At the far end, the front of the Day Tank has been used to mount all the fuel filters, Alfa Laval centrifuge and fuel transfer valve manifolds are out in the open and at perfect height when standing in front of them. Underneath that shelf the electrical wiring, external rectifiers and water distribution manifolds are also open and easy to access.
All of the plumbing is similarly open and easy to access such as this manifold with valves for all the cold water consumers in the Master Cabin.
One of our four primary principles for the design and build of Möbius was Low Maintenance and having all the components, wiring and plumbing open and so easily and comfortably accessed has been a big factor in achieving this goal throughout the whole boat.
Propulsion Perfection:
As we did for all the major components, we took a “systems” approach to the propulsion system from front of the engine to the prop. coupled to a Nogva Controllable Pitch Propeller (CPP) is also way up at the top of our list of favorite features on Möbius.
Our choice of a Gardner 6LXB engine aka Mr. Gee, coupled to a Nogva Controllable Pitch Propeller (CPP) via a Nogva HC-168 2.95:1 reduction gearbox is also way up at the top of our list of favorite features on Möbius.
The combination of the slow revving engine and lack of any transmission shifting created a seamless and smooth propulsion system. This was our first experience with CPP and it did take some time to learn how to run a boat where you first set the throttle at the RPM you want and then don’t touch it and just use the Pitch lever to increase pitch through an infinite range from zero/neutral to maximum pitch for the load and speed you want. With no shifting involved to go from forward to reverse it is eerily quiet and smooth when docking and when underway we essentially run the boat based on the EGT or Exhaust Gas Temperature meter to get the just right pitch for any speed we want.
We cruise between 8.5-9 knots and after 7300 nautical miles our overall propulsion efficiency has us averaging about 1.85 L/NM @ 8.5kts which we are eXtremely pleased with.
The dedicated “propulsion room” is another of my most favorite design decisions as it similarly provides open and easy access to Mr. Gee and all his components, ….. as well as the Nogva gearbox, coupling and Tides Marine dripless prop shaft seal. I am able to stand, sit or kneel on the grated composite flooring on all sides and with a full meter of width all around and each grate can be easily lifted out of the way to provide access underneath if needed. Having a dedicated engine room with nothing but the engine inside keeps everything inside easy to see and work on, easy to keep well ventilated and all the other components typically found in engine rooms such as fuel filters, batteries and system components are kept OUT of this environments heat and vibration. More examples of how well the open and accessible systems design is one of our favorite features.
Layout (cabin locations, balance living vs functional, up/down)
The overall interior layout also makes it way to the top of our favorite aspects of live aboard Möbius. For us it has the Goldilocks balance between amount of living space vs functional systems space and our decision to have a very large forepeak up front and then an even larger engine room/workshop space in the rear has resulted in a great layout as well as keeping these spaces completely separate with their own dedicated access so you never need to go through a living space area to get to something in the forepeak or engine room or workshop. The vertical layout has also worked out eXtremely well for us with each cabin a few steps below the SuperSalon and the SkyBridge up above. One of the most useful features of our layout is having an enormous “Basement” area below the floor of the SuperSalon. We designed this to be 1.2m/ 4ft high such that you can easily move around by bending over and not hit your head on anything and then sit or kneel to access any of the equipment mounted on intermediate floor to ceiling walls or access any of the many storage bins and shelves in the Basement. The stairs leading down into the SuperSalon from the Aft Deck on the Left and then around to the stairs down into the Ships Office and Guest cabin on the Right provide excellent access between all these areas. Very difficult to photograph but hopefully this pano shot of the SuperSalon will help convey why we like this layout with the 360 degrees of glass so much.
SkyBridge
We knew we wanted a Flybridge overtop of the main Salon or House so this was part of the design from the beginning but I don’t think either of us appreciated just how much we would enjoy this feature and how much time we would spend up here both when at anchor and underway. Part of what makes this space work so well is our decision to put the Upper Helm at the Aft end of the SkyBridge. As we’ve done in several areas of the boat we have created an initial prototype for the seating in this SkyBridge Lounge area by using patio furniture which we rearrange from time to time to figure out what will work best longer term. So far this L shaped layout has worked out best. There are great sight lines when sitting in the Helm chair just outside this photo on the far Left and yet still takes full advantage of the height for sight lines through the 360 degrees of windows that surround this entire space. The Bow and the side rub rails are all fully visible from the Helm chair. The roof overtop of the outdoor galley down on the Aft Deck does prevent a direct view of the transom but otherwise the sight lines Aft are great and we have a camera that displays a birds eye view of the transom on the Helm displays if needed when backing into a dock.
The Helm down in the SuperSalon duplicates the Upper SkyBridge Helm. But unless the weather is very cold or wet we much prefer to run the boat from the SkyBridge with its added height and even better visibility.
At anchor it also makes a great office space and a comfy bed for naps and off watch time as well. So the SkyBridge definitely makes it onto our top favorites list.
Hot Water & Heated Floors
Another example of the advantages of taking a Systems approach is our Domestic Hot Water system or DHW and probably fair to say that the heart of our DHW system that puts his solidly on our top favorites is our decision to install a Kabola diesel fired boiler. Located with all the other system components in the Workshop it is out of the way yet easily accessible. The 75L Kabola boiler is our primary source of DHW as it circulates through one of three heat exchanger circuits in our Calorifier that stores all our hot water as can be seen in this cutaway demo. The second heat exchanger circuit routes hot water from our Gardner engine and so whenever we are running the boat this provides all our hot water instead of the Kabola boiler. The third heat source is a 240V electrical heating element which we can use if the water based heat exchangers should ever fail.
However the one feature of our DHW that truly steals the show in cold weather is mostly invisible and that our Heated Floors. Underneath the vinyl flooring in all the living spaces there are circuits of plastic PEX tubing that circulates hot water and provides a creature comfort in colder climates that is difficult to adequately describe in words. A detailed description of the whole heated floor system can be found HERE in this previous blog post.
As you can read in that more detailed blog post, this is quite a simple system really but does take a bit to get your head around how it works as this is all part of the overall domestic hot water system so that all the water flowing through the floor PEX is coming from the Calorifier in the Basement circulating the same water as distributed to all the sinks and showers on the boat. No valves to adjust or turn on/off it all works by virtue of how this “Open Direct” plumbing design dictates.
Overtop of the PEX tubing and rigid foam, these industrial vinyl floor planks provide a fantastic floor in all weather conditions and are specifically made to work well with heated floors. Critical for our use on a boat, these vinyl floor planks have a simulated wood grain texture molded in which has proven to be completely skid proof even with wet feet and any spills clean up easily. After two years of rigorous use these floors show zero signs of wear or marks which helps keep them on our top favorites list.
There are three independent zones for the two cabins and the SuperSalon and each is controlled by one of these easy to set thermostats which maintain whatever temperature you want.
The manifolds and pumps are mounted down in the Basement up against the Aft bulkhead and yet another example of how easy this whole system is to access.
Battery & Solar Based Electrical System
Yet another systems approach on our top favorites list is our overall Electrical system. It is “battery based” in that all four voltages; 12V + 24V DC and 120V + 240V AC comes from our 1800Ah @ 24V House Battery bank. AC is created via the 5 Victron MultiPlus inverter/chargers and the DC is provided via three DC distribution boxes; Central Main in the Basement plus one in the Forepeak and one in the Workshop for the high amperage circuits there. Solar is our primary source for recharging the house batteries most of the time but when we are underway the two massive 250A x 24V Electrodyne alternators with WakeSpeed 500 regulators provide up to 9KW of power and we also have the option of connecting to shore power whenever we are in a marina. There are eight 320W solar panels that form the roof of our SkyBridge as seen in the photo above and then three more mounted on top of the cantilevered roof over the Outside Galley on the Aft Deck as seen here. And then three more mounted in a hinged frame in front of the SkyBridge. These 14 solar panels add up to just over 4kW of potential power and most days our battery monitors show an actual input of between 1kW during the winter months and up to over 2.5kWh of power during summer hours. Each solar panel has its own MPPT controller which are mounted in the Basement and feed into individual circuit breakers for further control as seen here. Having a dedicated MPPT for each panel reduces the impact of any shading on any panel and helps with the overall performance of our solar system. This screen shot from our Victron VRM display shows a summary for our solar output vs electrical consumption so far in 2023. And this summary of the past 2 days, April 28+29 2023 lets you see how it varies throughout a 24 hour day. We have not been in a marina or connected to shore power in the past four months and the combination of solar and alternator power is keeping our batteries 100% charged every day and so easily makes it onto our favorites list!
Handholds Everywhere for Everyone
Safety was another of the four design principles we had and one example that has proven to be a big favorite is the way we were able to ensure that there were super solid hand holds for EVERY person onboard from children to adults.
On the exterior the handholds are all 30mm diameter thick walled AL pipe such as these on the aft end of the house roof near the Aft Deck. These pipe handholds also make for eXcellent strong points for fastening things with Dyneme and other lines. Perhaps one of the most important spots for handholds is along the side decks when you are moving between the Fore and Aft Deck areas. On the left you can see the continuous length of AL pipe that runs along the entire edge of the house roof and then the three rows of Dyneema landlines that Christine rigged between each of the sturdy vertical AL stanchion pipes. The top lifeline is 1 meter above the deck so hits most adults about waist height which ensures that even if you were to be thrown against these you would be stopped and not flipped over top. Up at the Bow there is a very solid set of AL pipe railings that wrap all the way around and make this area extremely safe and fun spot to be for dolphin watching or just dangling your feet overboard and taking in the scenery at anchor or underway. At the far end of the Aft Deck there are solid AL pipe railings for the corner of the deck before the stairs going down to the Swim Step and then a solid AL pipe railing on the other side of the steps. In the Engine Room, Mr. Gee has a full set of AL pipe railings wrapped around him to ensure you can’t be tipped over onto him in rough seas and these have worked out very well to also provide good support as you are leaned over working on various parts. On the interior of the boat one of our favorite esthetic features of the gorgeous Rosewood cabinetry is the design we came up with to incorporate built in hand holds to the design that are located on all the cabinets in all the cabins and SuperSalon. This example is on the corner of the Galley cabinet across from where the fridges are located. These solid Rosewood edges wrap around the whole boat to form what we call our “Blue Horizon Line” and their key feature is that they have a deep groove that is at about waist height where your fingers naturally slip in to provide an eXtremely secure hand hold. We have had our grandchildren onboard several times now and these have worked out as designed to be at Goldilocks height and size for their fingers too.
Interior Materials:
Possibly saving the best for last, something that brings us joy every day is the choice of interior materials we made.
The Rosewood we chose for all the cabinetry really steals the show and this shot of the Galley cabinets will give you some idea. We were very fortunate that Naval Yachts happened to have their very best cabinetmakers throughout the entire build and they were a joy to work together with to produce details such as how all the grain is bookmatched such that it literally flows from one piece to the next. This was made possible because after months of searching we were able to purchase an entire flitch of Brazilian Rosewood that had been flat cut from the same log. As each slice comes off they stack these in order and therefore the grain of each slice follows the next. The other key was finding a matching stack of solid Rosewood that would be used to build the frames and every edge of every panel. NO veneer edging allowed! Unlike more typical construction, all plywood edges had these T shaped pieces of solid Rosewood glued in place and then the veneer was applied AFTER so that it overlapped the solid wood edging. What this does is ensure that there are no glue joints exposed and they become invisible as they gradually transition from veneer to solid. When these panels would be used for a corner of a cabinet, a thick piece of solid Rosewood was glued glued on and then this solid edge was rounded over in a shaper to create a large radius corner The Rosewood was more than 11X the cost of any other hardwood so to help stretch the prized solid pieces it was sometimes possible to glue on a piece of cheaper hardwood like this and then round the Rosewood for the corner. For the very large radius corners, strips of solid Rosewood were edge glued up and then radiused like this. Or like this. When combined with the Turquoise Turkish marble and the inset Blue Horizon line strips, the end result was well worth the extra time and expense to build. We carried the same combination of materials throughout both cabins, Salon and Galley and I hope these few photos help you see why this puts a smile on our faces every day. There is a LOT more that we like about our dear Möbius and she has definitely lived up to being “Project Goldilocks” by being just right, just for us but the above items hit upon most of our top favorite features and I hope this review was worthwhile. Of course there is always the other end of the spectrum and so in the next blog post I will follow up by reviewing things that have not worked out as well or are things we want to change so do stay tuned for that.
In last week’s “Toasty Tootsies” post I went over the way our In Floor Heating system works and concluded my explanation with what I thought was a rhetorical question;
“Brilliantly simple don’t you think??!!
Well, based on the number of comments and Emails I received, while our In Floor Heating system might indeed be “Brilliantly Simple” my explanation was NOT! Therefore, let me try and mend this by revisiting our In Floor Heating and do my best to improve my explanation of how this Open Direct type of system works. If I’m successful I think that most of you will come to agree with my assessment that this Open Direct system is indeed “Brilliantly Simple”!
But you will be the judge of that and so Please do add your comments as to how well this second attempt helps you to understand how our In Floor and Domestic Hot Water systems work and don’t hesitate to add your additional questions and things that still don’t make sense to you.
OK, here is my second attempt to show how this all works;
Deeper Dive into our Open Direct System;
One of the Emails I received, (thanks Benjamin), asked the following set of questions that included many of the points of confusion others sent me so I thought I’d use this to frame this expanded explanation of the Open Direct system I used to design our In Floor Heating or IFH and Domestic Hot Water or DHW System.
Benjamin wrote:
If I understood your installation diagram correctly, you run the drinking water through the same pipes as the water for the underfloor heating. Drinking water and “heating water” are identical, or not installed separately. First of all, this is economical because you one water circuit less. But I have a question about summer operation: drinking water and heating are usually installed separately, because in summer mode
you want to avoid hot water flowing through the heating system, and
the water should not stand still in parts of the circuit for a longer period of time to prevent the formation of legionella.
You can probably avoid point a. with valves that separate the entire heating circuit from the drinking water circuit in summer. But if the heating circuit is not flushed for several months during summer operation, legionella can form and then be flushed into the drinking water circuit when the heating system is put into operation. How do you avoid this? Is the underfloor heating completely drained during summer operation modus?
Thank you very much for further information!
First, let me try to resolve some common sources of misunderstanding that Benjamin and many of you mentioned;
I should have emphasized more how the various parts of our overall water systems are separated from each other. In last week’s post I mostly left out the Cold or “drinking” water system so it needs to be understood that this has its own set of plumbing and ALL the water we drink and cook with comes directly from the water tanks to the cold water taps/showers onboard. All the water in our water tanks comes directly from the onboard watermaker so it is as clean and close to pure H2O as is possible.
One of the things that seems to confuse many people at first is to understand that there are only TWO conditions that causes water to FLOW in a plumbing system:
The regular water pressure in the system causes water to flow IF and ONLY IF water is being REMOVED from the system.
There is a continuous circulation loop with its own PUMP that causes water to flow round and round through the CIRCULATION loop.
When neither 1 or 2 is true, there is NO FLOW of water through the plumbing.
The Hot/Warm systems are the ones based on the Open/Direct system on Möbius and this has TWO different but interconnected systems:
The In Floor Heating Mode which provides WARM water to heat floors when wanted.
The DHW Domestic Hot Water Mode which provides HOT water to all the sinks and showers at all times.
I have modified the following illustrations from last week’s post to show a clearer picture of how these two systems work.
When no Hot water tap is open there is NO Cold water entering the system. However, when one of the In Floor thermostats turns on a Zone Circulation Pump, warm water then flows out of the Calorifier, through the in floor PEX tubing and back into the Calorifier. This is a continuous loop so warm water is flowing through the floor tubing anytime the circulation pump is running.
The DHW system always takes priority so whenever a Hot water tap is opened, the system works like this in DHW Mode. When any HOT water outlet at a sink or shower is opened, the regular pressure in the Cold water system which runs about 60 PSI, causes Cold water to enter and flow through the PEX tubing in the floors to refill the hot water that has been removed from the Calorifier. When the Hot water tap is closed the system automatically reverts back to In Floor Heating Mode and the Circulation Pump causes Warm water to circulate though the floor and keep it toasty warm. To answer another question I received and as should now make sense, we do not actually “drink” water going through the DHW or In Floor Heating, though there would be no problems if we did.
It can initially be a bit confusing because when Hot water is consumed (taken out of the Calorifier by turning on the hot water at a sink or shower) and the system is in DHW mode as per above, it is necessary to replace the water that has been removed from the Calorifier so Cold “drinking water” does enter the DHW system. This is exactly the same as in ANY home or other setup with a Water Heater or Calorifier; when Hot water is taken out, it must be replaced with water from the Cold water supply.
In operation this works extremely well and does so automatically by design. Anytime Hot water is wanted, the Open Direct system ensures that this takes priority and Hot water flows from the Calorifier to the tap or shower as long as it is open. As soon as you close that tap and are no longer needing Hot water, the system reverts to In Floor Heating Mode.
Summer vs Winter:
The difference between Summer and Winter is that in Summer/hot weather when the In Floor Heating is turned off, the IFH Circulation pumps never turn on so no water is flowing through the floor UNTIL a Hot Water tap is opened. Said another way, the ONLY time water is flowing through the floor PEX is when the system is in DHW Mode because a Hot water tap has been turned on. The rest of the time, there is NO water flowing through the floor tubes.
This turns out to be part of the “brilliance” of this type of system in my opinion because the design ensures that the In Floor Heating automatically adapts to whatever the weather is. HOT water ONLY flows through the floors when it is needed and the circulation pumps turn on in colder weather. NO hot water flows through the floors in warmer weather because the circulation pumps never turn on.
This sets up the ideal system as it ensures that the water in the PEX tubing is always being refreshed and is never standing still for any length of time.
Better yet, in hot weather, when you are using DHW and there is water flowing through the floor tubes, it is absorbing some of the heat in the room or from sun shining on the floors and so that by the time the water gets to the Calorifier, it is now a bit warmer so you save energy in the Calorifier because the replacement water has already been warmed up and does not take as much energy to heat up to whatever temperature you have sent the Calorifier to maintain.
Once this all makes sense I think you too will see just how “brilliantly simple” this Open Direct system is. It is completely automatic, no valves or switches to change, no need to drain the system or do anything else other than keep using everything on the boat/house as you always have.
Trust me, it does take a while to figure this type of system out. It is one of those things where it is very simple but ONLY after you understand it! To begin with, it can be VERY confusing! My suggestion, and what I used to do a lot of, is to draw out a schematic for yourself and trace the flow of water in the different scenarios from summer to winter and from In Floor Heat Mode to DHW mode and I think you will quickly see how it works.
Hope this helps and if it still doesn’t make sense just send me additional questions in the “Join the Discussion” box below to let me know what’s confusing or not making sense and I will do my best to answer them all as quickly as possible or in next week’s post.
Thanks for your patience with this not always so clear ex teacher!
Welcome to this first Möbius Update post of 2022! I hope you have 2022 off to a great start already as we work to do the same here aboard the Good Ship Möbius. I am slowly warming up to getting back to weekly blog posts here so thanks very much for your patience in waiting for this first one of the new year. I’ve been warming up particularly well now that I have the in floor heating all working which I think may well be Captain Christine’s favorite feature so far.
And apparently she’s not the only one as Ruby & Barney have discovered how well the in floor heating heats up their little doggie beds.
With the weather getting colder since our return at the beginning of December from our 2 months back in Canada and the USA, I’ve been mostly working on getting all the Domestic Hot Water or DHW systems fully operational and all the various bugs worked out. I’ve received a number of questions about how our DHW system works and what components we have installed and a lot of interest in the in-floor heating system we’ve installed and that’s what Ill do my best to cover here in this week’s update.
Domestic Hot Water System
Our DHW system is pretty straight forward so let me cover that first.
There are just three basic components of the DHW System: Kabola KB45 Ecoline Combi diesel fired water heater/boiler
IsoTemp 75L Calorifier
with 3 internal heat exchangers
Hot Water circulation Loop that runs around the circumference of the boat
The Kabola is the primary heating source for the whole DHW system as it is eXtremely efficient, quiet and very trouble free.
Ours is the “Combi” model which means that it has two separate heating loops inside. The primary loop heats up the water in the IsoTherm Calorifier which holds all the DHW for the boat and the other loop heats up the fluid going to the four air handlers which can heat the air in each cabin if needed. This view of the back of the Kabola shows the primary boiler loop Supply/Return connections at #1 & #2 and then the secondary loop flows in/out of #5 & 6. The Primary loop has a built in circulation pump that constantly circulates the antifreeze/water fluid and a thermostat turns the burner on/off to keep the fluid at whatever temperature you set.
The secondary “Combi” loop has an external circulation pump that is part of the Webasto AirCon/Heating system.
I’ve removed the front of the burner to show you how the internal heat exchangers work. The large black tank you see on the Left contains all the antifreeze/water fluid and the diesel burner is inside the Grey tube on the Right.
The larger diameter tubes/holes on the top are the secondary loop and the larger number on the bottom are the primary heating loop. The Kabola is super simple to operate, just turn it on, set the thermostat to be whatever degrees you want the internal fluid inside the boiler to maintain and then pretty much forget it. When the fluid temp goes down the burner automatically fires up, heats the water a bit past the set temp and then shuts off. Could not be simpler or more efficient. Now let’s follow where the heated fluid as it leaves the Kabola and flows over to the heat exchanger loop inside the Calorifier.
This cutaway view shows how our IsoTherm Calorifier is similarly multi purposed with three different sources of heat to keep our DHW nice and hot. There are two loops of SS pipes on the bottom here, one which has the fluid from the Kabola flowing in/out of it and the other loop a similar antifreeze/water fluid flowing through from the Gardner engine’s “cooling” system. The top most loop is a 240V electric heating element that we can use if needed.
All SS construction and the outside never even gets warm so the heavy insulation has been working very well and the Kabola does not need to fire up very often to keep the water nice and hot all the time.
Turning the Calorifier above around and looking at the outside this sketch shows the three pairs of In/Out connections; one for the hot fluid from the Kabola, one for the hot fluid from the Gardner (when it is running) and then the Cold Fresh Water In and DHW Out. The end of the Calorifier in the illustration above is under my hand and if you look closely (click to enlarge any photo) you can see a Yellow ring labelled “Engine Water” on the far Right and a White ring on the Left labelled “Kabola White” On the top Right the Red Label marks where the Hot Water comes out through the black wrapped insulated pipes which are split into one line going to the DHW loop and the other with the bottom Left Mixing Valve going to the In Floor Heating loops. Closer view of the adjustable Mixing Valve which controls the temperature of the water going out to the In Floor Heating system which wants warm not Hot water, usually about 55C/131F whereas the DHW runs about 65C/150F. To make sure there is always hot water ready to come out of each sink and shower, the DHW flows around the whole boat in a continuous loop of insulated pipe. In this schematic the DHW loop is on the Right hand side and the In/Out to the In Floor Heating is on the Left.
I will get back to the In Floor Heating a bit later below but the key point to keep in mind is that the In Floor Heating is all part of the same DHW system.
To keep the DHW flowing through the hot water loop feeding each tap and shower, this magnetically coupled impeller pump is very small, about the size of your fist and is highly efficiency with very low power consumption and absolutely silent.
We now have very hot water readily available at every tap and shower onboard and we are both eXtremely pleased with how well the whole DHW system has been working.
In-Floor Heating or IFH
Winters here in southern Turkey are rather mild compared to many locations with lows down to 8C/46F a few nights and day time highs as much as 20C/68F but winter is also when we get rainy days and so can get chilly and so the real star of our DHW system the past while has been having nice warm floors throughout the boat to keep us toasty warm.
It has taken me some time to get it all adjusted and working properly but it is now running flawlessly and silently so let me walk you through how this system works.
As with the DHW system above, the In Floor Heating or IFH is a very simple system with the following main components:
An Azel I-Link controller with three thermostats for each IFH zone on the boat, one in each cabin and one in the SuperSalon. A pair of SS manifolds, top Red one where the Warm water (about 50C/122F coming in at the top and then the Returning slightly cooler water exiting out the bottom Blue manifold. Each of the I-Link thermostats controls one of these Taco 3 speed 1/25HP circulation pumps which circulates the fresh DHW water from the Calorifier through the PEX tubing that runs in loops underneath all our floors as needed to keep our tootsies nice and warm. We worked out these serpentine patterns of PEX tubing in each of the three Zones to provide an even distribution of heat wherever there were bare floors and not under the built in furniture. This is in the Master Cabin; Head/shower lower Left, bed center Right. This is how the PEX tubing was laid down before the 10mm marine plywood floors were installed. Serpentine grooves were cut into the foam with a router. Foil tape was set into the groove in the foam and then the 15mm PEX tubing was press fit into the groove. Here is how it looked in the forward end of the SuperSalon.
Let’s take a minute to walk through a brief explanation of how the In Floor Heating system works.
For our IFH system I decided to use what is called the “Open Direct” style as it is incredibly simple and efficient. OPEN in this case refers to the fact that the IFH system is “open” to the same DHW that we use onboard for sinks and showers. A “closed” system would be like the loops of antifreeze/water that the Kabola uses to heat up the water in the Calorifier.
DIRECT refers to the fact that the fresh warm water flowing through the PEX tubing is heating the floors directly, not through a heat exchanger like those in the Calorifier. This simple schematic adds the details of how the IFH portion of our DHW system works. Warm water coming out of the Calorifier via the mixing valve is pumped on demand through the PEX tubing in the floors by the Taco circulation pumps. Part of the simple brilliance of an Open Direct system is that the DHW always takes precedence so anytime you turn on a hot water tap or the shower, hot water is diverted to them until shut of when the warm water returns to circulate through the floors as needed. Huh? How does THAT work you ask? The following two illustrations should help make sense of this very simple but initially a bit confusing system works.
This is In Floor Heating Mode that happens whenever the thermostat for this IFH Zone turns the circulation pump ON and warm DHW is pumped through the under floor PEX tubing in that zone and then returned back to the Calorifier (Water Heater). Keep in mind that even though the whole DHW system is pressurized to about 4 Bar/60 PSI in this mode the ONLY way water flows is IF the circulation pump is running. Even though it is available, Cold water cannot enter the system when the pump comes on unless someone is taking hot water out of the system by taking a shower, doing dishes, etc..
When a Hot water tap is opened then the pressure drops and the system reverts to this DHW Mode and Hot water flows out of the Calorifier (Water Heater) to the HW tap and Cold water flows into the system to replace it.
The cold water goes through heating tubes within the floor on its way to the water heater. This flow pattern provides limited free cooling and other benefits. Stagnation is prevented and priority is given to the domestic hot water use over the space heating use. A small amount of free cooling is realized in the summer.
Note that NO additional equipment, parts or power is needed to make these two modes work automatically.
Brilliantly simple don’t you think??!!
I found these beautiful SS manifolds on Amazon for a great price and they made the whole plumbing of the system very straightforward to install and control. Red handled ball valve top Left is where the warm water from the Calorifier flows INTO the system and is made available to each of the three Red Flow Control Meters/Valves and into the PEX fittings on the bottom.
Cooler water from each continuous PEX loop flows into the bottom three fittings, each with the White capped control valve and then OUT the Blue ball valve and back to the Calorifier. Each continuous loop of PEX in a zone has one of these Red Flow Meters that you adjust to get the correct flow rate, which is about 1-1.5 L/min for our zones. Each ball valve has a temp gauge so you can check the differential of the water temp coming IN and how much it drops going OUT. Ideal is about 50C/122F coming in and 40C/104 going OUT and you adjust this via the Mixing Valve on the Calorifier. Here is what the whole IFH manifold looks like when assembled and installed with the three Taco circulation pumps.
These Taco pumps are pretty much bullet proof and are miserly power consumers as they are very small 1/25HP AC motors. The Taco pumps are absolutely silent and can be run at one of three speed settings to get you the flow you want. They are also dead quiet and you can only tell they are running by watching the flow meters. This Azel I-Link controller is the brains of the IFH system and takes its orders from one of the three thermostats conveniently located in each Zone. Each thermostat is very easy to adjust and provides a full set of information of room temp, floor temp, when the “heating mode” or pumps are on, etc.. Here is what one looks like in operation today. Room temp is 22.3C/72F, Set Point is 24C, floor temp is 49C. Each Zone has one of these little temperature sensors installed which connects to the thermostat of that Zone so it and the controller knows when to turn the circulation pump Off/On. The main control box of the I-Link system is carefully tucked away into a small alcove in the Ship’s Office where it is well protected but easily viewed by opening the cupboard door. Red lights on the far Right indicate when one of the 3 zones is working (pump on).
And that is it! Just like the Kabola boiler, this is a “set it and forget it” system and has been working flawlessly and very easy to adjust as we learned what temps we liked in each zone.
You have to experience it to understand just how fabulous Toasty Tootsies are when the weather turns colder outside!
And that’s a wrap for this week, the first blog and Möbius Update of 2022 is done and dusted!
Hope you enjoyed it and please be sure to tell me if you did or didn’t and add any other questions in the “Join the Discussion” box below.
I’ll do my best to be back again next weekend with another Möbius Update for you and thanks again for your patience in waiting for this one to go live.
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