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.
WOW Wayne, what a detailed description! I’m very happy that you got the remaining bugs out of your floor heating system. Down in Alanya, we are getting by with just a little 1200W electric heater (thermostat controlled) keeping our boat in the 19-21C range. When a low pressure system comes in, the temperature outside is chilly, agreed.
Very high praise from someone like you Wade who has built his own boat from the ground up so thanks for the kind words and glad to know you enjoyed that last post going over our DHW and In Floor heating. We are experiencing similar weather here in Finike as you do in Alanya I think and today is a gorgeous sunny day but we’ve had several good storms with some good thunder and lightning since we got back here at the beginning of December so we too have been getting some chillier days and nights. Makes us appreciate having hot water and warm floors all the more and I’m also working on bringing our other modes of interior heating online and hope to soon be testing out the reverse cycle option for air heat via the Webasto “Chiller” and Air Handlers system. I’ve also got the option of using the DHW to heat up the fluid flowing to the Air Handlers rather than use the Chiller and I will be working on getting that all tested out in the coming weeks as well. So the chillier weather for the next month or two should provide us with good opportunities to test out these interior heating systems and I’ll post those as updates here on the blog as I do.
Trust all is well with Joana and with both of you? Look forward to finding a time for us to get together before we leave here which we hope to be in April some time.
The water chiller is not used for heating normally?
I am typing this in a warmth of reverse cycle air conditioner, its chilly outside and warm inside and it takes very little (shore) power to heat the boat without burning any diesel 🙂
Hi Andy, great to hear from you again and hope that you have 2022 off to a great start.
We have designed three different ways of heating the interior living spaces on Möbius; Reverse Cycle as you are using, In Floor Heating, and then also using DHW to warm up the fluid going to the Air Handlers from the “chiller”. We will use the In Floor Heating as our primary source of keeping the interior temps up in colder weather as we find that it is the Goldilocks of interior heating for us. Nothing better than having toasty tootsies as well as slightly cooler air up higher for our upper bodies. However in the situation where we are returning to the boat in colder climates after leaving it for extended times, the whole boat will be cold including the water in the Calorifier and so we would therefore rely on the Reverse Cycle to initially warm up the boat and also turn on the Kabola boiler to start heating up the water in the Calorifier. Once that DHW gets up to temp, then I can turn on the In Floor Heating, turn off the Reverse Cycle and switch over to using the DHW to keep the fluid flowing to all the Air Handlers up to temperature so that they can continue to keep the interior nice and warm while the floors warm up. I have separate thermostats to control the In Floor Heating independently of the Air Handlers so I can adjust the Air Handler settings lower as the floors warm up and turn them off whenever the In Floor Heating is sufficient on its own to keep the interior temps where we want them.
Our most common use case is to be at anchor so we have optimized the systems on Möbius for this and so the primary sources of heat for the DHW are the Kabola and then the Gardner engine whenever it is running while the boat is underway. I will have to wait and see what we learn from testing out all three heating systems but my guess right now is that the most efficient setup for us will be to use the DHW as our primary source for heating the interior by mostly using the In Floor Heating and then supplement this with the Air Handlers getting their warm fluid from the DHW. Once I have run the Air Handlers using both the Reverse Cycle and DHW, I can see what the differences are and figure out when best to use one over the other.
Right now, getting the DHW system up and running fully has been my first priority and this then allowed me to get the In Floor Heating working and begin our testing of those systems. I’ve got a few other jobs onboard that I need to attend to first but I will be trying out the Reverse Cycle and the DHW to heat to the fluid going to the Air Handlers and start to track and learn how these systems work to keep the boat nice and warm during the next few months of “winter” here in Finike. As I gather that data and experiences I’ll write them up and post as Updates here.
Glad to hear that you are keeping toasty warm with your Reverse Cycle heating and that it is working out so well for you.
Thanks for your continues interest and contributions here, always much appreciated.
I meant there is no plumbing / valving to heat the underfloor heating circuit with the central water chiller in reverse cycle?
That would be ideal in Med type of a weather, when heating is required daily, but there is plenty of sun available to run the chiller, with enough heat capacity to store, even store it for the night maybe?
Thanks for the clarification on your previous question Andy. I understand now I’m just not sure how often we would be in the situation you describe where we have an excess of solar output in weather that is cold enough to need the In Floor Heating. As I’ve outlined in the last two blog posts, our In Floor Heating is a “Open Direct” design so it is Domestic Hot Water that is flowing through the PEX tubing in the floors and so using the heat from the Reverse Cycle “chiller” would be “indirect” by using a heat exchanger to use the RC heat to heat the DHW in the Calorifier. All very possible as we have two heat exchanger coils in the Calorifier which circulate water/anti freeze fluid, one getting its heat from the Gardner when it is running and the other getting its heat from the Kabola boiler. The Kabola also has two heat exchangers inside, the primary that transfers heat inside the Calorifier and the secondary which can heat the fluid flowing from the “chiller” to the Air Handlers in each interior space. I’d have to think it through in more detail, it would probably not require too much additional plumbing to “T” into that second loop to allow the Reverse Cycle heat to go to the Calorifer and contribute in that way. So it’s possible, I’m just not sure how often this would be the more desirable solution for interior heating.
Once I can start collecting actual performance data on how well the multiple ways I have of heating the DHW as well as the interior, I will be able to use this data to help decide on any any changes or additions, so stay tuned for more on that later this year.
Thanks for your always thoughtful suggestions and please keep them coming.