Boat heating wish list

[boatpoker]

Originally Posted by DeepFrz

Oh, no, don't do this. Insulation is very important in a cold or hot climate. There are plenty of threads on CF on this subject. Insulation - ventilation - HVAC. They work hand in hand.

Full time liveaboard since 98'. Most winters in Toronto.
Pay attention to DeepFrz !

Also whatever insulation you use it must be air tight against the hull. We used 2" thick pink foamboard cut to 4" wide planks and each plank sealed with Sikaflex.

PS. We've never had a condensation issue. In fact we run a humidifier all winter and struggle to keep humidity up at 40 - 45%.

[Paul L]

If you want to play with electronic control, one thing I like on the raditor in our v-berth. It has a wall thermostat. When it goes on it turns on the furnace and the fan at the raditor. There is also a seperate sensor on the raditor that disables the fan till the raditor comes up to temperature. We usual have the heater off while we sleep. Turn it on early morning. This stops cold air being blown around from the raditor till the system warms. Just a little extra comfort.

[GILow]

Originally Posted by DeepFrz

Oh, no, don't do this. Insulation is very important in a cold or hot climate. There are plenty of threads on CF on this subject. Insulation - ventilation - HVAC. They work hand in hand.

Originally Posted by Pete7

We lived on board for a month in Feb 18, one of the coldest in the UK for several decades. Tins of food in the lockers were running with condensation as was the inside of the GRP hull. 48 hours later with the Airtop blown heater dried things out somewhat by taking cold dry air from outside, heating it and forcing damp air inside out through the vents. However, I did have to take the floors up to mop up in what has always been a dry boat.

To take the beautiful furniture out is going to damage it hence why I haven't insulated the hull. If you can, then do add closed cell foam insulation to as much of the hull as you can. Finally think about carpet mats for the floors. We have them to stop the dog scratching the varnished floor and that helped to insulate the boat too.

Pete

Originally Posted by ausnp84

Yep, I’d second fitting closed cell foam insulation to cut down condensation. Fitted the 25mm version in my steel ketch and never, ever had condensation, even living aboard in grim UK winters.

N

Originally Posted by stormalong

Condensation will be an issue simply because you are living aboard. Breathing, cooking and showering all add moisture to the air. Consider a room size portable dehumidifier. I did that for a few years and it made a world of difference. Drain the condensate into the bilge and let the automatic bilge pump deal with it.

You said your hull is very thick. What is it's composition? Foam core might help. Closed cell foam sheet is available in various thicknesses. While the interior is out it is a great time to do this. I have 1/4 inch that was installed when the boat was built but I would go at least twice that, more if possible.

Originally Posted by Ray-Dianna

We keep our sailboat at Campbell River, BC, it can get to to 0ºF or lower and remain there for 1-2 months. We use the shrink plastic and double sided tape on all ports and hatches to prevent condensation there. We also applied double reflective bubble insulation on all surfaces to help with keeping cold out and reflecting the warm air back into boat. We also use a de-humidifier (best idea) to reduce remaining moisture thru out the boat. The boat is heated with the espar D4 heater on a 37 footer.
If you have the chance to apply insulation, do it now.

OK, I'd be an idiot to ignore the advice. Insulation will be installed.

[Wotname]

The beauties of insulation are manifold.

It operates 24/7
It doesn't cost anything to run
It works for hot and cold climes
It doesn't require any maintenance
It is only done once



and it takes 10 kts off a gale at anchor - well the sound reduction makes it seem so. You know how a 15 knot breeze sounds like 25 knot gale when it springs up zerodarkthirty at anchor, well the insulation reduces it back to 15 knots

[GILow]

Originally Posted by Paul L

If you want to play with electronic control, one thing I like on the raditor in our v-berth. It has a wall thermostat. When it goes on it turns on the furnace and the fan at the raditor. There is also a seperate sensor on the raditor that disables the fan till the raditor comes up to temperature. We usual have the heater off while we sleep. Turn it on early morning. This stops cold air being blown around from the raditor till the system warms. Just a little extra comfort.

Sounds neat. I was thinking of something slightly similar: I have a single variable speed pump that circulates hot coolant through the entire heating loop, then I would switch on the fans of the heater units in the area of the boat I want to heat, while leaving the others off.

I have practically infinite control options using picaxe chips and DS18B20 temperature sensors.

Just trying to combine this logic with the idea of the pipes doubling to keep the bilges dry and warm as suggested earlier and in ColdEh's thread, plus the heated towel rail idea which I had also had suggested to me previously by a CF member.

[surazo]

anyone is using a webasto diesel heater ? which are your opinion ? .Thanks

[GILow]

Originally Posted by bcboomer

I used 3/4" pex hydronic tubing and Sea Tech quick connect fittings.
Because the storage areas behind the settees etc all go below the waterline, I ran the supply and return lines in the bottom of these. That eliminated the perpetual damp.
I configured the feed/return in parallel but don't think it was worth the effort in a small boat.
One return line, after the heat exchanger, is 3/4" copper and run under the floor where we sit for meals. Really nice on chilly mornings.
The head is heated via a heated towel bar. If you go that route be sure you really flush it well.

Gold, thank you.

I am thinking how I can incorporate all of this with my pipe runs. (And the towel rail idea was also suggested to me by another CF member I highly respect a few years ago. But point noted about flushing... They didn't mention THAT problem.)

I am configuring my system in parallel. In part because I want maximum efficiency, in part because the boat is a reasonable size and the last heater in the circuit would be pretty cold, but mainly because the layout makes it easier to do parallel than series.

[GILow]

Originally Posted by surazo

anyone is using a webasto diesel heater ? which are your opinion ? .Thanks

I think that is what ColdEh is using in his system.

I have the 5kW Thermotop C and I am happy with it so far, although all I have done is some simple testing of a mockup of my system. A bit noisy, but it heated the water fast and was simple to get running.

[cj88]

As far as insulation goes Aerocel is pretty good but $$, also have a look at K-FLEX. There are other alternatives but as you reduce effectiveness you need to increase thickness. Try and minimise any thermal bridging where possible as that will help reduce condensation points.

[daga]

I have a saloon aluminium boat that I bought in Hobart a few years back. I spent two winters living on the boat while I set it up. Anjea has 50-100mm of sprayed on closed cell foam above the waterline and no insulation below. There was no heating initially and since I was in a marina I got by with a small blower heater. The 750W setting was more than enough to keep the boat warm. But of course I wanted heating away from the dock so one of the first things I did was to fit a Webasto diesel hot air blower. This worked well except that I had some difficulty sourcing clean dry fresh air for it. In the end I just drew the air from the locker in which the heater was installed, which can result in a slight off smell sometimes, depending on how long wet sails are stored there! The other issue is that the diesel heater exhaust is on the transom and in a very light breeze from behind the smell is detectable in the cockpit.

My main problem with heating in general is condensation on the saloon windows. I have not yet found a way to combat this, and since I am now in the tropics the subject has taken a back seat.

I recommend you:
- apply as much insulation above the waterline as you can,
- provide exhaust for cooking areas,
- draw fresh clean cold dry air from outside, rather than circulating damp air
- use carpet
- bear in mind hydronic systems take a while to heat up and cool down and thus are not so responsive to rapidly changing conditions in weather, door/hatches opening/closing, etc.
- be aware that the diesel heater exhaust can drift into the boat if it is low down.

[Paul L]

One more suggestion. Put in a winter/summer 3 way valve. On summer it shorts the coolant flow circuit so it only heats domestic hot water, not the boat.

[GILow]

Originally Posted by Paul L

One more suggestion. Put in a winter/summer 3 way valve. On summer it shorts the coolant flow circuit so it only heats domestic hot water, not the boat.

Yes, done already. I modified ColdEh's design so that the circuit that runs the heating is totally independent of the boiler and house hot water.

It was something I realised early, that the needs of a Canadian boater might be slightly different to an Ozzie boater.

See picture...

[daga]

Oh, and if you are going to bypass the heating as Paul L suggests, and you are going to sail the tropics, then install a bypass for the water heater as well. The last thing you want in the tropics is anything that stores heat inside your well-insulated boat!

[GILow]

Originally Posted by daga

I have a saloon aluminium boat that I bought in Hobart a few years back. I spent two winters living on the boat while I set it up. Anjea has 50-100mm of sprayed on closed cell foam above the waterline and no insulation below. There was no heating initially and since I was in a marina I got by with a small blower heater. The 750W setting was more than enough to keep the boat warm. But of course I wanted heating away from the dock so one of the first things I did was to fit a Webasto diesel hot air blower. This worked well except that I had some difficulty sourcing clean dry fresh air for it. In the end I just drew the air from the locker in which the heater was installed, which can result in a slight off smell sometimes, depending on how long wet sails are stored there! The other issue is that the diesel heater exhaust is on the transom and in a very light breeze from behind the smell is detectable in the cockpit.

My main problem with heating in general is condensation on the saloon windows. I have not yet found a way to combat this, and since I am now in the tropics the subject has taken a back seat.

I recommend you:
- apply as much insulation above the waterline as you can,
- provide exhaust for cooking areas,
- draw fresh clean cold dry air from outside, rather than circulating damp air
- use carpet
- bear in mind hydronic systems take a while to heat up and cool down and thus are not so responsive to rapidly changing conditions in weather, door/hatches opening/closing, etc.
- be aware that the diesel heater exhaust can drift into the boat if it is low down.

Thank you Daga, lots of great stuff here...

The first remark is that I salute your hardiness. A couple I know who have a Tartan 42 bailed out from Tassie in May because they were too cold, and they had a 2kW diesel air heater like yours. And they are no wimps!

Good point about air supply. I am using a set of heater units scavenged from Toyota Hiace vans, and I have kept the air control valves and whatnots because I think it would be good if I could adjust their air SOURCE at need. Your comments reinforce that this might be a good idea.

I had to look up your boat (lovely boat BTW, very fond of Van de Statds, grew up with one) to understand the saloon windows issue. Yes, I can see that would be an issue. The Swanson should be ok, my deck house is out of bounds when it comes to heating, so all I have to manage are 6 small opening portlights. Which will, no doubt, become steamed up.

Point about exhaust fumes noted. Not sure how much choice I will have, it will be exiting the boat around midships with my design. Very small chance of the exhaust becoming momentarily submerged so I have designed a closure system for under way. (Had to make my own exhaust outlet for that though.)

The response speed of my system SHOULD be fast because the buffer tank is permanently hot, as it also provides my house hot water. But yes, I had a hydronically heated house 20 years ago and it was a good 20 minutes before there was a noticeable change.

Had not thought of spray on foam insulation... I will add that to the options.

Thanks again.

Matt

[GILow]

Originally Posted by daga

Oh, and if you are going to bypass the heating as Paul L suggests, and you are going to sail the tropics, then install a bypass for the water heater as well. The last thing you want in the tropics is anything that stores heat inside your well-insulated boat!

Ummm.... sure I can bypass the water heater... but then... I wouldn't have hot water.

Which, in the tropics, probably isn't an issue.

Yeah, I figured there will be long periods of time where the whole lot is shut down.