All things Heating

[Cavalier MK2]

Thanks Roy. Looking forward to seeing you up here. Anacortes is good to hook up but with the San Juans on the doors step there are more scenic places to anchor.

[mark_morwood]

We have a diesel Espar which we haven't used since we got to the tropics, but was great when I was working on the boat over winter in Boston! The main unit is under the settee in the saloon with ducting down to the 4 cabins. It works well, though the saloon has a tendency to get hotter than the cabins.

If I was installing heating in our boat from scratch, I would install two forced air diesel heaters, one in each engine room with a single outlet into the aft cabin. The hot air would flow forward through the hull, and up into the saloon. You would need to leave the doors open to the berths/cabins, but as a family cruising with us in one hull and the kids in another, that is our normal arrangement. I've not tried this, but it was an idea I read about from others who had used it successfully.

The advantages are:
- no ducting
- 2 smaller rather than one larger unit for redundancy
- just run one if you are using just one hull and the saloon

Disadvantages:
- 2 units rather than one
- doesn't provide as much fine tuning for different cabins/berths

Mark.

[rabbi]

Originally Posted by mark_morwood

We have a diesel Espar which we haven't used since we got to the tropics, but was great when I was working on the boat over winter in Boston! The main unit is under the settee in the saloon with ducting down to the 4 cabins. It works well, though the saloon has a tendency to get hotter than the cabins.

If I was installing heating in our boat from scratch, I would install two forced air diesel heaters, one in each engine room with a single outlet into the aft cabin. The hot air would flow forward through the hull, and up into the saloon. You would need to leave the doors open to the berths/cabins, but as a family cruising with us in one hull and the kids in another, that is our normal arrangement. I've not tried this, but it was an idea I read about from others who had used it successfully.

The advantages are:
- no ducting
- 2 smaller rather than one larger unit for redundancy
- just run one if you are using just one hull and the saloon

Disadvantages:
- 2 units rather than one
- doesn't provide as much fine tuning for different cabins/berths

Mark.

Things to consider:
A bigger unit is not much more expensive than a small one, so two small ones increase cost significantly, especially if one includes all the installation material that goes along with the second unit like another air intake and exhaust through-hulls, silencer, etc. Savings on ducting don't offset this. Plus the installation work for the second unit can easily offset the time one would need for routing the ducting.
The smaller ones seem to be a bit louder and I would not want it right beside my head in the engine room.

We have just one unit and ductig to all three cabins and the head as well as saloon. All vents can be closed to heat only certain areas of the boat. These air vents are webasto but they use the same ducting sizes as Espar (or Eberspächer, which is the real company name of Espar). For temps below freezing point our unit is too small to heat all areas so i shut off the areas I'm not in.

[rabbi]

One thing i forgot about forced air heating:
Don't forget the insulation for the ducting.otherwise much of the heat is lost behind lockers and under floorpanels.

[hpeer]

Ducting depends upon your layout. Our 44 has a D4 which is pretty small, it has about 3 feet of ducting total.

The 33 has more, but I had that professionally installed. Then I had to reinstall the heater. I could have used much less.

[befree]

When dealing with heat in cold climates it is important to heat all areas evenly including surfaces, if this is not done, you will end up with fungal growth (mold) on cold surfaces. You should heat all areas including all of the enclosed areas, like cabinets and closets, even under the mattresses. I would recommend that the mattresses be raised slightly of surfaces with sufficient air to flow under them. I would also recommend that ducting be run through closets to prevent cool spots. Keep in mind that warm air rises and cool air sinks. I would probably put the furnace in the main saloon with ducting run to all forward and stern locations, I would also recommend that all diffusers be equipped with flow dampers to adjust the amount of warmth in the cabins, for larger boats or more sophisticated installations you can also use remote thermostats that control the temperature using flow dampers. All ducting must have insulation for efficiency. Larger heaters are usually more efficient and quieter than smaller ones.

[CaptTom]

Originally Posted by leftbrainstuff

We have an espar similar to webasto...

We tend to run ours as night approaches. We also heat our hot water with it. So its dinner followed by a shower.

Whoa. Heat water with a Webasto forced air unit? I hadn't heard of that option. Is this one of those squared-off torpedo shaped things, or a proper hydronic heater?

I'm looking to add a basic forced-air diesel heater, probably a Russian knock-off, just to take the chill off when I can't run the existing reverse-cycle. If I could get hot water from it too, that would be even better.

[newhaul]

Originally Posted by CaptTom

Whoa. Heat water with a Webasto forced air unit? I hadn't heard of that option. Is this one of those squared-off torpedo shaped things, or a proper hydronic heater?

I'm looking to add a basic forced-air diesel heater, probably a Russian knock-off, just to take the chill off when I can't run the existing reverse-cycle. If I could get hot water from it too, that would be even better.

I would assume they have one of the hydronic units they do make both

[Cheechako]

Originally Posted by Paul L

Forced air heating (Espar or Webasto) would require a lot of large and difficult to run ducting. Hard enough on a mono. A piped coolant system with radiators would be much easier to install, take up less space, supply hot water and be easier to create effective zones. ITR has some interesting systems, along with Webasto and Espar.

Littlechay
Which Refleks models were you referring to?

My cat had plenty of room for one midship under the cockpit/helm station. Two short ducts would have likely worked for one side and salon. maybe an 8 ft duct for the other side. Just thinking out loud though, not sure if there were some obstructions or not.... Might have been easier than a mono which would carry thru settees compartments etc.

[rabbi]

Originally Posted by CaptTom

Whoa. Heat water with a Webasto forced air unit? I hadn't heard of that option. Is this one of those squared-off torpedo shaped things, or a proper hydronic heater?

I'm looking to add a basic forced-air diesel heater, probably a Russian knock-off, just to take the chill off when I can't run the existing reverse-cycle. If I could get hot water from it too, that would be even better.

There is a company called Truma that builds heating systems used in most RVs in germany. Most are gas based and have a boiler built-in but they also make a water heater that can be integrated into a forced air heating system.
They simply run a hot air duct through the water, maybe a bit more sophisticated but thats the basic idea. I guess it takes ages to heat the water but if the heating runs through the night you could have a hot shower in the morning. Or maybe not, its just 5 liters

Google 'truma therme' to get an idea, and maybe build one yourself or just use the truma therme as a heat exchanger and gravity-couple it with a bigger hot water tank.

[GILow]

Originally Posted by rabbi

There is a company called Truma that builds heating systems used in most RVs in germany. Most are gas based and have a boiler built-in but they also make a water heater that can be integrated into a forced air heating.

We used the diesel version of this combo unit in a camper van in the UK. It was very very good. I considered it for our boat but it was quite bulky and would have been hard to fit. If you have the space it would be well with considering. It gave useful hot water in about 10 minutes and useful hot air even quicker.


Sent from my iPhone using Cruisers Sailing Forum

[CaptTom]

Truma looks great, however, I don't have the room and really don't need any more hot water most of the time. I don't really plan to need a lot of heat. This would be sort of a back-up for those times I'd like to take the chill off without AC power. In other words, I can't justify the cost of a high-end system.

I looked back at some old threads about Planar (Russion knock-off) heaters, but the posts are kind of old now and I'm wondering if anyone has any recent experience with them.

[Palarran]

Originally Posted by psychfeld

I'm trying to find out what is a more feasible way to incorporate an efficient heat source in a catamaran. I'm going to be circumnavigating with whichever cat I buy and there don't seem to be many with existing heat. So I will probably be installing something aftermarket.

I'd like to find out what anyone's experience has been with whatever heat source they've been using. I have used a small West Marine space heater in my small sailboat in the Seattle winters. They suck a tremendous amount of power for the heat provided. I would like a heat source that could work independent of shore power.

I don't seem to find any threads on CF searching for heater or heating systems, maybe I am not searching properly.

Thanks!

Interesting responses to your question. The first question I would have asked is why do you need one and do you have a generator already. If so, how big is it.

Most circumnavigations are done on the milk route. There is very little need for heat, much more for air conditioning. If you have a generator and its a small unit, like 5kw, IMO you are better putting in a forced air heat pump. I think personally this is the best set up for a catamaran unless you are willing to only heat one hull or even one berth. If you don't want to hassle with that, you can even get one that's a console and ducts out the boat in a 4" tube. Very easy to install, like 15 minutes, and costs about $600.