Most effective, cost efficient, and reliable way to heat trawler cabin

[bahlinout]

Some of the coldest nights I've spent on board were in Florida! November 2023, Englewood (S of Sarasota), reverse cycle ac quit reversing, 45F overnight. I used every blanket

Your post brought back a memory from my time in the Coast Guard. I was stationed on a cutter in Honolulu, toasty warm all the time. We went to San Francisco for a yard period. The ship yard disabled our vessel ( long story, union dispute).

We were in a dry dock from Nov to May. It was the coldest winter I ever spent, and I grew up in MA. Temps were never bad but a steel hull and no power of any sort with rain all the time. I can still remember it and it was 60years ago.

 

[ranger58sb]

Some of the coldest nights I've spent on board were in Florida! November 2023, Englewood (S of Sarasota), reverse cycle ac quit reversing, 45F overnight. I used every blanket on board!

Surprised to hear that. I'd have thought water temps shouldn't have been too low for reverse cycle...

-Chris

 

[socalrider]

Builder said I needed to install a second flue pipe from the bottom so there would be two holes on the deck with two Charlie Nobles to balance the back pressure.

Would an H-style cowl have fixed the problem?

 

[mvweebles]

Would an H-style cowl have fixed the problem? View attachment 170822

Tried it. Didn't do squat. I had 6-foot of flue including two feet above deck. I tried the little fan recommended by Sigmar which was also pretty noisy.

When it was breezy it would sometimes back puff and extinguish the flame while fuel was still being fed to the hot burner this vaporizing the diesel. Didn't happen often but given the extreme danger of super heated vaporized diesel, sure put me on notice.

Peter

 

[deputybubba]

Any recommendations on the oil filled radiators ?
Was told this was the best way to 'warm' the boat during the PNW winter, not run A/C on Heat.
Thanks
Bruce

 

[Mac2]

I’ve used them all. Dyson is the best Ive used-heat and efficiency wise. Very expensive. I’ve never bought new. I bought two used off eBay.

 

[Bmarler]

Any recommendations on the oil filled radiators ?
Was told this was the best way to 'warm' the boat during the PNW winter, not run A/C on Heat.
Thanks
Bruce

If you aren’t living aboard the oil filled heaters are good for keeping things from freezing. They’re about the safest option for a heater you can leave unattended. That said, be certain that your electrical system is up to the constant draw. The outlets, and shore connections need to be clean and tight.
If you need heat you can live with, you need something with a fan to move the air.

 

[deputybubba]

If you aren’t living aboard the oil filled heaters are good for keeping things from freezing. They’re about the safest option for a heater you can leave unattended. That said, be certain that your electrical system is up to the constant draw. The outlets, and shore connections need to be clean and tight.
If you need heat you can live with, you need something with a fan to move the air.

Nope you hit it exactly , just to keep things from freezing.
I see them on Amazon from $70's to $130...
I think I need 4 ... 1 engine room, 1 master, 1 VIP and then 1 in the salon.
Thanks for your reply.

 

[O C Diver]

Nope you hit it exactly , just to keep things from freezing.
I see them on Amazon from $70's to $130...
I think I need 4 ... 1 engine room, 1 master, 1 VIP and then 1 in the salon.
Thanks for your reply.

If you have a block heater, that's all you need for the engine room.

Ted

 

[Portage_Bay]

Nope you hit it exactly , just to keep things from freezing.
I see them on Amazon from $70's to $130...
I think I need 4 ... 1 engine room, 1 master, 1 VIP and then 1 in the salon.
Thanks for your reply.

I trust the Caframo True North heaters to run unattended. They CAN'T fall over. Low power settings. Reliable thermostat. Freeze protection setting.

https://defender.com/assets/pdf/caframo/9206_true_north_manual.pdf?srsltid=AfmBOooqxcefyO1wl-0qocWlXM5WQiXoNL1891VI-8CpEASJYWWia0TC

 

[Bmarler]

I trust the Caframo True North heaters to run unattended. They CAN'T fall over. Low power settings. Reliable thermostat. Freeze protection setting.

https://defender.com/assets/pdf/caframo/9206_true_north_manual.pdf?srsltid=AfmBOooqxcefyO1wl-0qocWlXM5WQiXoNL1891VI-8CpEASJYWWia0TC

As a live aboard, this is the heater to use. Low profile, good air movement, good heat/ fan combinations for setting amp draw. These used to sell rebranded as west marine, not sure if they still do or not.

 

[heysteve]

I recently installed a couple Wallas heaters after evaluating hydronic systems. Like everything else, they both have pros and cons.

The primary appeal of the Wallas was its terrific ability to dehumidify as well as heat. As liveaboards in the PNW, that's a big deal. The second reason was fuel efficiency as it has the ability to automatically adjust the heat output from 1% to 100% instead of a simple on/off cycle.

But you won't save any money over hydronic as their stuff is expensive. Fortunately, the quality is very high and they have a reputation for reliability.

 

[Portage_Bay]

I recently installed a couple Wallas heaters after evaluating hydronic systems. Like everything else, they both have pros and cons.

The primary appeal of the Wallas was its terrific ability to dehumidify as well as heat. As liveaboards in the PNW, that's a big deal. The second reason was fuel efficiency as it has the ability to automatically adjust the heat output from 1% to 100% instead of a simple on/off cycle.

But you won't save any money over hydronic as their stuff is expensive. Fortunately, the quality is very high and they have a reputation for reliability.

I've boated and lived aboard with drip diesel, forced air and hydronic. To control humidity it's more about ventilation than heat source. Forced air cleverly installed does have one big advantage. The return air can be mixed with exterior air when needed to quickly bring humidity down.

 

[SteveK]

I've boated and lived aboard with drip diesel, forced air and hydronic. To control humidity it's more about ventilation than heat source. Forced air cleverly installed does have one big advantage. The return air can be mixed with exterior air when needed to quickly bring humidity down.

I have wondered about intake from outside. But here in PNW the humidity fall/winter is higher outside, so I do not think it would work.

 

[Portage_Bay]

I have wondered about intake from outside. But here in PNW the humidity fall/winter is higher outside, so I do not think it would work.

I'm in the PNW as well. It does work, it's all about relative humidity.

 

[SteveK]

I'm in the PNW as well. It does work, it's all about relative humidity.

There is 80% outside boat, 55% inside at the moment.
Would it not have to be less outside to flush out inside?

 

[NoRain]

Relative humidity is a function of temperature. eg https://byjus.com/physics/relative-..., it will,the relative humidity will increase.

 

[Portage_Bay]

There is 80% outside boat, 55% inside at the moment.
Would it not have to be less outside to flush out inside?

I don't recall the calculations and I'm too lazy to look it up. The principal is simple. Cold air holds less moisture than warm air. Warm the air and it dries out. Cool the air and humidity rises. So bring in air at 4 C at high humidity then warm it to 22 C and it dries out. When that incoming air displaces the warm humid air in the boat things dry out.

 

[Portage_Bay]

Now think about the boat heating options commonly available.

Drip diesel consumes cabin air for combustion. Cold wet air is brought in and warmed. Humidity drops.

Forced air and hydronic generally have the combustion chamber in the engine room. They just reheat the already warm and humid cabin air. To dry things out outside air needs to be brought in.

The realistic effect is that i see no difference between forced air or hydronic in ability to dry the cabin air without ventilation.

If you want an easy demonstration drive your car on a cold wet PNW winter day with 4 people inside. Windows closed, air on recirculation, heat on, AC off (many newer cars automatically turn on AC in defrost mode even if the heat is on) the windows will fog up. Next set the controls to bring in.fresh air, make.no other changes. The windows will clear. Relative humidity at work.

Note in some newer cars you can't run this test. The climate control is too smart and will defeat your efforts .

 

[heysteve]

I've boated and lived aboard with drip diesel, forced air and hydronic. To control humidity it's more about ventilation than heat source. Forced air cleverly installed does have one big advantage. The return air can be mixed with exterior air when needed to quickly bring humidity down.

This mix of interior and exterior air is the recommended installation method. The heater has two inputs so one takes return air from the cabin and the other from outside. The Spartan model also has a "ventilation" mode that will substantially increase the airflow regardless of the heater setting. This really helps to remove excess humidity after cooking or showering.

Of course, introducing outside air can be done in other ways. It's just that the Wallas approach makes it easy to do.

 

[Bmarler]

I always ran my espar forced air with outside air on the intakes. It pressurized the cabin interior slightly and kept it from being drafty. Boat interior was very dry that way and I didn’t notice any shortage of hot air at the outlets.
My current hydronic system just recirculates interior air. There’s a couple of towel bar radiators too that help cut down humidity, but the forced air did a better job at humidity control than the hydronic.

 

[Portage_Bay]

I always ran my espar forced air with outside air on the intakes. It pressurized the cabin interior slightly and kept it from being drafty. Boat interior was very dry that way and I didn’t notice any shortage of hot air at the outlets.
My current hydronic system just recirculates interior air. There’s a couple of towel bar radiators too that help cut down humidity, but the forced air did a better job at humidity control than the hydronic.

Because your installation brought outside air in. If a forced air system does not bring in outside air then it performs in a similar manner to a hydronic system.

 

[Bmarler]

Because your installation brought outside air in. If a forced air system does not bring in outside air then it performs in a similar manner to a hydronic system.

Yeah, I knew that when I installed the forced air. I like the power and versatility of the hydronic better for heating the whole boat, but if I would have been the installer of the system my current boat came with, I sure would have done it different. In fact I may change it one of these days so it can bring in some fresh air to heat. Just not sure where to put the intake vent yet, or find the spare time to do it.

 

[Portage_Bay]

Ok, we're on the same page! I meant on insult. If I could start fresh with a roomy budget it would be hydronic hands down. But it's a big complicated installation which means either a lot of DIY time or a lot of tech $$$ which the may well lead to a lot of DIY fix all of their mistakes time. Which is what happened to me.

If the boat is old enough, mine was, then ventilation is no problem because the outside air just leaks in. If it's newer and tighter then a small inlet at one end and a small outlet at the other extreme with a small low volume fan is all that is needed.

The only heat I'll never use again ever is propane catalytic. Fortunately that's out of favor, I don't even know if you can purchase the components anymore. The catalytic combustion produces water vapor, lots of it. That was on my first boat, an old old woodie. I ripped that out and put in a small wood/coal burner. Messy but very warm and dry.

 

[Delta Riverat]

I'm happy with my $100 Vevor 5 KW. I should add it's probably closer to $250 after you replace the junk kit parts with the good stuff. Today The boat was 45F when I arrived and 60F an hour later when I turned the heater down. Yeah I have one of the old leaky (far from air tight) boats too.

As far as bang for buck the cheap Chinese heaters rock!