I am looking at putting an Espar Hydronic 5 boiler in my C30 to replace my ancient Artic that finally died. Where do you get the cabin heaters to complete the system. Most that I have found are much too big for my boat.
Hydronic heat fan/coil
- Thread starter Hayden Watson
- Start date
Not familiar with these guys but they look like they may have something useful..
http://www.aquahot.com/
http://www.aquahot.com/
Three zones, 3 heaters. Thirty-three foot sailboat. Quiet, efficent, do their job.
http://www.msrheaters.com/
Hayden, if you are serious about hydronic heating, talk to Sure Marine in Seattle about designing a “system”that takes into account heating system and matching boiler/blower/ hot water units along with boat volume. They are the best around..
In my case I cannot under-build because with a C30 they do not make a boiler that is small enough to be "too small". I could easily over-build but am installing two 10k btu fan-coils and I can't go any smaller and still have some zone control. I am building the system with the simplest circuit possible with the possibility of modifying the loop later to get faster heating. I will run it with the following primary loop. boiler, domestic water heater, quarter berth, forward cabin/head, engine, boiler. I will also have a summer loop that by-passes the cabin heaters and engine. If it takes too long to heat from a cold start I will move the water heater to between the forward cabin and engine and make a small circuit loop to just the cabin heaters with a thermostat to transfer the heat to the WH and engine as the system comes up to temp.
And yes I am an engineer. I got my BS in Mechanical engineering but am licensed as a Structural.
And yes I am an engineer. I got my BS in Mechanical engineering but am licensed as a Structural.
Some questions and comments
1) what do you mean by engine? Is this a fan unit in the engine space or are you connecting engine coolant with heating? Or?
2) I would stay with only one loop. The “summer loop” would be the primary without fan units operating and get rid of several valves.
3) the more lineal distance means a bigger water pump. The boiler requires a minimum water flow through it.
4) Remember the water resoivoir tank needs to be the highest in the system. This is where all the air goes.
5) Put a garden hose T at the lowest point to fill the system from. This drives air up to the open resoiver tank
6) If using heater hose, use min of 5/8”. Maybe something better has come up in last few decades.
7) Don’t run the loop through the fan units in series. The last one will get far less hot water. Plumb the fan units in parallel to the loop. This will require some loop diameter reductions where the fan units are to force some water through the fan units.
Engineer also..or was...sparky, but I’ve installed three hydronics in 44’ boats..Hope some of these comments help!
1) what do you mean by engine? Is this a fan unit in the engine space or are you connecting engine coolant with heating? Or?
2) I would stay with only one loop. The “summer loop” would be the primary without fan units operating and get rid of several valves.
3) the more lineal distance means a bigger water pump. The boiler requires a minimum water flow through it.
4) Remember the water resoivoir tank needs to be the highest in the system. This is where all the air goes.
5) Put a garden hose T at the lowest point to fill the system from. This drives air up to the open resoiver tank
6) If using heater hose, use min of 5/8”. Maybe something better has come up in last few decades.
7) Don’t run the loop through the fan units in series. The last one will get far less hot water. Plumb the fan units in parallel to the loop. This will require some loop diameter reductions where the fan units are to force some water through the fan units.
Engineer also..or was...sparky, but I’ve installed three hydronics in 44’ boats..Hope some of these comments help!
Thanks for the comments Mark. Responses by the numbers.
1. plumbed into the engine cooling system to a. allow the engine to provide heat for HW and cabin while motoring, provide additional thermal mass heating to minimize boiler run-times and to preheat for easier starting.
2. Summer loop is so that in the few hot weeks, we can heat the water heater without filling the whole system with hot water.
3. This is a 30' boat so none of the distances are that great. I know of another member that is using the same boiler in a 43' boat and doesn't seem to have problems with pushing the water.
4. expansion tank at high point goes without saying.
5. All of my heater units have air bleeders in them to purge air. I will use circulation pump to fill from empty which should get most of the air out in the first run but will also monitor returning bubbles in the reservoir and open bleeders to insure no air is in the system.
6. All fittings on boiler and fan-coils are 3/4" barb and I am using 3/4"ø heater hose throughout which should minimize head load by reducing the velocity over a smaller hose.
7. I am not a fan of parallel heating loops because they are difficult to balance. In series, you know that all heater are getting water. At first the upstream will rob from the downstream but as the boat warms up, the fans will start to cycle off and everything will be warm. I will also have far more btu's than needed for this size boat.
I will have the main cabin on the Espar thermostat and get a second to control the fan in the forward cabin/head for control.
I also think I will add a thermostatically controlled small-loop circuit / big-loop circuit next year after I see how it is performing to get quicker cabin heating.
1. plumbed into the engine cooling system to a. allow the engine to provide heat for HW and cabin while motoring, provide additional thermal mass heating to minimize boiler run-times and to preheat for easier starting.
2. Summer loop is so that in the few hot weeks, we can heat the water heater without filling the whole system with hot water.
3. This is a 30' boat so none of the distances are that great. I know of another member that is using the same boiler in a 43' boat and doesn't seem to have problems with pushing the water.
4. expansion tank at high point goes without saying.
5. All of my heater units have air bleeders in them to purge air. I will use circulation pump to fill from empty which should get most of the air out in the first run but will also monitor returning bubbles in the reservoir and open bleeders to insure no air is in the system.
6. All fittings on boiler and fan-coils are 3/4" barb and I am using 3/4"ø heater hose throughout which should minimize head load by reducing the velocity over a smaller hose.
7. I am not a fan of parallel heating loops because they are difficult to balance. In series, you know that all heater are getting water. At first the upstream will rob from the downstream but as the boat warms up, the fans will start to cycle off and everything will be warm. I will also have far more btu's than needed for this size boat.
I will have the main cabin on the Espar thermostat and get a second to control the fan in the forward cabin/head for control.
I also think I will add a thermostatically controlled small-loop circuit / big-loop circuit next year after I see how it is performing to get quicker cabin heating.