Summer Discussion: Diesel Heater Installation on Multihulls

[rabbi]

worst will be rainy nights just above freezing point. If you can manage these with a bit extra heat form the other heaters you should be fine.

Just don't invite a missus for sleepover, that would cause condensation as we all know.

[Chotu]

Originally Posted by rabbi

worst will be rainy nights just above freezing point. If you can manage these with a bit extra heat form the other heaters you should be fine.

Just don't invite a missus for sleepover, that would cause condensation as we all know.

Ha ha ha ha ha.

You know, I’m a little frustrated about that actually. My interior is not at a level where I can have anyone over yet. It’s a bit like camping on the water still in here. People don’t really understand boat construction so they don’t really know that it’s a high quality boat. Just because the surfaces are not yet finished they assume it’s junk inside.

Also there is no shower yet and the head facilities are a porta potty. Drinking water comes from a foot pump. There were a lot of other priorities other than making out good for women at this point lol

I think the little bit of extra heat on those damp nights above freezing will be good. If I can save diesel and power on the majority of nights where it is not too bad, then I won’t have much problem cranking it all up on the damp nights and of course the very, very cold nights in January and February

Thanks for pushing this part of the discussion. It’s important and I wasn’t really thinking about it as much as I should have been

[Chotu]

Originally Posted by rslifkin

That sounds pretty good to me, and it also sounds like you're sitting at a decent balance between dry enough to avoid condensation, but not unpleasantly dry inside the boat. If you start to get some condensation on really cold nights, leaving the heater in the other hull running at its lowest setting should be plenty to get rid of it (and on a cold night I expect that will warm the boat some, but far from the temperature and fuel consumption of heating things fully).

Yes it seems like that will be the perfect plan. Just running the ones a little lower out there when things start getting really cold. Also, I have to watch the freezing point out there as well. I definitely don’t want it to get below freezing in the cabin.

Also, heating the place up in the morning takes quite a while even with three heaters running. I am noticing that today. Lingering in bed I’m not getting up quickly because I’m waiting for things to warm up

[rslifkin]

Originally Posted by Chotu

Yes it seems like that will be the perfect plan. Just running the ones a little lower out there when things start getting really cold. Also, I have to watch the freezing point out there as well. I definitely don’t want it to get below freezing in the cabin.

Also, heating the place up in the morning takes quite a while even with three heaters running. I am noticing that today. Lingering in bed I’m not getting up quickly because I’m waiting for things to warm up

Thinking about it, those heaters have a temperature setting, right? They just won't shut off entirely and will stay at "1" and overshoot the temp if only a little heat is needed? In that case, on the really cold nights, I'd just set the other hull to 45 - 50 degrees. It'll run on its lowest setting unless it starts to get cold enough to worry about freezing in there, then it'll turn up to maintain that temp.

[Chotu]

Originally Posted by rslifkin

Thinking about it, those heaters have a temperature setting, right? They just won't shut off entirely and will stay at "1" and overshoot the temp if only a little heat is needed? In that case, on the really cold nights, I'd just set the other hull to 45 - 50 degrees. It'll run on its lowest setting unless it starts to get cold enough to worry about freezing in there, then it'll turn up to maintain that temp.

Well, no. Not exactly. The problem is that the control units and thermostats are centrally located on the centerline of the boat. They can’t reach all the way to the hulls. They don’t measure the temperature in each hull. They probably should have. Maybe on the permanent installation I will try to make sure of that.

They measure the temperature in the bridge deck salon.

They also are a bit wonky. I don’t really get a good control out of them. The temperature goes up and down strangely. They don’t seem to kick on strong enough when they should as the temperature drops. They don’t seem to turn off when the temperature is too high.

Now, these are the old control units. I also have one of the newer units that I have not tested out thoroughly for temperature control. Basically a diesel heater is a diesel heater. It’s all about the control unit. Some are very advanced. They have aftermarket ones that can do all sorts of things. Some are just really pathetic like the ones I have on the two older control units

[rslifkin]

Originally Posted by Chotu

Well, no. Not exactly. The problem is that the control units and thermostats are centrally located on the centerline of the boat. They can’t reach all the way to the hulls. They don’t measure the temperature in each hull. They probably should have. Maybe on the permanent installation I will try to make sure of that.

They measure the temperature in the bridge deck salon.

They also are a bit wonky. I don’t really get a good control out of them. The temperature is go up and down strangely. They don’t seem to kick on strong enough when they should as the temperature drops. They don’t seem to turn off when the temperature is too high.

Now, these are the old control units. I also have one of the newer units that I have not tested out thoroughly for temperature control. Basically a diesel heater is a diesel heater. It’s all about the control unit. Some are very advanced. They have aftermarket ones that can do all sorts of things. Some are just really pathetic like the ones I have on the two older control units

Moving the controls down into the hulls definitely seems like a good idea, let each heater measure the temperature in the space it's heating and the thermostat function should become at least a little bit more useful.

[Chotu]

Originally Posted by rslifkin

Moving the controls down into the hulls definitely seems like a good idea, let each heater measure the temperature in the space it's heating and the thermostat function should become at least a little bit more useful.

Yeah I wonder if that’s even possible. I don’t know how much resistance these controllers can take before they stop working properly. I don’t know if I can double and triple the length of the control wires. Maybe.

But I bet it would work a lot better that way. Each one it’s own zone.

Also the reason it took so long to heat up this morning is because the remote controls were not working too well. You get audio feedback knowing that the thing turned on or off, but as you are adjusting the temperature up and down you do not get any audio feedback. So I had one heater on 10, one heater on 2, and the other heater on 1. Lol

Definitely user error this morning. I might have to actually get out of bed and set them properly in the mornings.

[Chotu]

Oh no! One big flaw in the plan. Trying to make breakfast and I found my olive oil stopped working ha ha

have to bring that in the state room

[Chotu]

So far so good. 24° last night.

The only problem I’m having are user error. I forgot to keep all of the heat on at a decent level when it went below freezing. I was tired and did the routine of putting the one that heats my cabin at a low setting and the one in the other hull at its lowest setting. No bridge deck heat on at all. Woke up VERY cold.

Then, it took a long time to come up to temperature in my room. I was in there freezing staying in bed trying to stay warm after having turned on all 3 heaters to 60%. It just wasn’t warming up in my room. So I got up for a bathroom run and it was toasty in the bridge deck area.

Still adjusting techniques a little bit as it gets colder and colder.

The really good news is the bridgedeck is pretty easy to heat up quickly with 3 heaters

[Chotu]

Continuing to update the thread with more information and experience about heating the larger volume of a catamaran with diesel heaters.

It’s been down in the 20s at night. As it gets colder, I’m noticing that I had to follow Rslifkin’s advice about plugging up the cracks/drafts.

It’s not so much that the heaters couldn’t keep up but the cold draft blowing on me was just not fun.

Now that I have plugged up all most of the holes, I can sit at a comfortable 70°F in 24° weather. And that’s not even on high with the heaters.

So, for anyone that’s reading this and has a catamaran similar to mine, you’re going to need three Chinese diesel heaters to heat it properly and comfortably in the winter.

One nice thing about the third heater is it blows only on the bridge deck. And it blows out from under the settee warming the settee (er…um… ikea futon). It’s very nice. This is what I was missing. A nice source of heat that you can cozy up to and get warm when you have a chill. The bridge deck heater is perfect for that and it spends most of its time off actually. The other two are usually on and convection keeps the bridge deck a good temperature

I closed up my drafty opening, sliding windows using clear plastic from the hardware store. They are now airtight. The others are blocked off by the same foam insulation panels that I used in Florida to keep the heat out. When it’s like 5° out, there may be a time that I have to tape around the edges of those just to keep things from having condensation.

My doors aft are temporary and not well sealed at all. I could probably do a little more work there, but so far everything is going well.

[Chotu]

More updates.

Christmas is about here. in the 20s.

Glad i don’t have fancy wood or musical instruments aboard, but RIP mold, insects, bacteria. ha ha ha.


look at this humidity this morning

[rslifkin]

For outside temps in the 20s that's probably close to right where I'd want to see the indoor humidity. I'd probably target 35-ish percent. Pretty much unless you have really well insulated windows, etc. and nowhere that's likely to form condensation, you have to drop the humidity as the outside temp drops to avoid getting condensation in places you don't want. No different than a house in that sense.

[Chotu]

Originally Posted by rslifkin

For outside temps in the 20s that's probably close to right where I'd want to see the indoor humidity. I'd probably target 35-ish percent. Pretty much unless you have really well insulated windows, etc. and nowhere that's likely to form condensation, you have to drop the humidity as the outside temp drops to avoid getting condensation in places you don't want. No different than a house in that sense.

I remember you made a point a while ago I think in this thread that it was going to be not a lot different than a house.

you had that 100% correct.

running these oil burners is like running an oil burner in a house. Very similar.

it was also really important to seal up a lot of the cracks where drafts were coming in.

generally this boat has behaved exactly like a house when it comes to heating and temperature and humidity.

I definitely have really well insulated windows. I have 1 inch thick foam panels that I was using for keeping the sun out in Florida. With reflectix insulation on them. and I have taped around the edges of them to keep air from getting behind them.

I have two front windows that slide open. These are drafty. Just by design. They have rubber gaskets that leak a little bit of air around the edges.

i used that airtight, clear interior plastic window seal kits to seal those off because the drafts were not fun.