Heaters. Propane? Diesel?

[CarinaPDX]

Originally Posted by witzgall

THis is not universally true. For instance, the Webasto DBW2010 puts out 45k btu, and is either on full blast (heats water) or off.

In what you quoted from my post it said "it will have to cycle to do it". I believe that is what you are describing...

Greg

[sailnow2011]

I am planning to install an RV furnace.
We already have propane, and can fit a 40# tank.
A 40# tank in winter, in a 40' RV lasted 2 weeks.

[Island Time O25]

Originally Posted by oregoncycle

Also I saw someone's comment about not driving a propane car and know that city buses and fleets of trucks all across the country use propane as their fuel.

I believe these buses run on CNG. But in Europe they often do modify passenger cars to run on propane, the reason being that large enough CNG tanks wold be too heavy for a small passenger car but are OK for a bus or a truck.

[ramblinrod]

Originally Posted by basssears

Curious, since it's come up, the skill level required to do an install of diesel forced air. Our new to us boat has ducting from a previous install, so if I could use that seems like I'm a step ahead, but wondering how challenging the rest of it is.... particularly curious about getting into the plastic fuel tank for diesel supply.

Haven't done a whole lot of research yet but partial to the Wallas 30DT based on what I've read about them.

-- Bass

Not familiar with Wallace. Espar is the market leader, and Websasto is a significant contender.

If the ducting is for a previous diesel forced air heating system, then there must be a lot of infrastructure present for the old (removed?) system. If the ducting is for an air con system, there will be more work to do.

You should be able to tap the fuel line to the engine rather than tap the fuel tank. If so, tap it after the water separator.

For a new install. Not for the faint of heart. Involves cutting a lot of holes in the boat.

If you can mount the diesel heater "engine" in an area "communicating" with the auxiliary engine compartment, that ventillation system will provide supply air.

If not already there from a previous system, you will have to mount a thruhull in the transom for exhaust.

RamblinRod
Marine Service Provider
About Sheen Marine

[jtsailjt]

Originally Posted by Sandero

It's kerosene... and Espar and Webasto should work fine with them. The diesel fired forced air is fast and pretty dry heat... but your metal bits like hatch and port frames will have lots of condensation... Most boats have poor thermal insulation... and will sweat when then inside air is warm... and people inside are putting moisture into the air by breathing and cooking.

But if the circulation air is drawn from outside where it's cold, that means it's also drier air that you are pumping into your boat, while displacing some of the warmer, moister air out, so eventually the inside of your boat gets pretty dry, eliminating or at least reducing the sweating on hatch and port frames that can be so annoying as it drips on you while laying in bed.

Another advantage of the forced air diesel heaters is that they have a thermostat, so if you are leaving your boat at midday when it's in the 60's outside and in the 70's inside, but don't plan to return until late evening when it's 40F outside and quickly cooling off inside, you can leave your heater turned on at an appropriate thermostat setting so the heater will kick on only when the temp inside falls below a certain level so your boat will be warm and dry feeling when you return but the heater won't have started running until it started to cool off so the actual run time will be minimal.

If you are doing the installation, make sure to include a heater outlet in the shower area. On a coolish day, if you use your heater to make it 80F in this area before jumping into the shower, you'll end up using a lot less water because you won't be leaving it running longer than necessary just to keep from shivering. Also, when offshore in cool, damp areas, there's nothing like being awakened for your wee hours watch, and being able to climb into your toasty warm and absolutely dry foulies that you left hanging in the shower soaking wet at the end of your last watch! I leave the port in the shower open (with a hood on it in case it's raining) so all that warm, moist air evaporating from the wet clothing has a place to go.

[basssears]

Thanks RamblinRod, previous system was a Wallas that's why I'm leaning that direction for replacement... even has a Wallas controller (unknown if working or not) installed already. So I should be good on ducting, although I have to investigate further... as others have pointed out the ducting might not have been done right, could even be the reason there's no heater in there anymore (bad ducting setup causes premature failure and you remove the heater).

Interestingly the Wallas installation manual states:
"If the device uses the main tank of the boat, note that the device cannot take the fuel from the same fuel output line as the engine of the boat."
... so looks like I have to put another hole in my tank. I plan on putting in a bus heater too so doubt I would use this much while underway under power, but I have also heard stories of diesel heaters that won't run well when the engine's running when you share a fuel supply (I think the engine takes all the fuel it wants leaving not enough for the heater).

Originally Posted by ramblinrod

If the ducting is for a previous diesel forced air heating system, then there must be a lot of infrastructure present for the old (removed?) system. If the ducting is for an air con system, there will be more work to do.

You should be able to tap the fuel line to the engine rather than tap the fuel tank. If so, tap it after the water separator.

[CarinaPDX]

Originally Posted by basssears

Interestingly the Wallas installation manual states:
"If the device uses the main tank of the boat, note that the device cannot take the fuel from the same fuel output line as the engine of the boat."
... so looks like I have to put another hole in my tank.

The problem arises when the fuel line at the tee has a vacuum when the engine is running. Buy a Walbro boost pump and install it in the heater fuel line just after the tee. Or use a day tank which gravity feeds the engine and heater.

Greg

[Sandero]

Originally Posted by jtsailjt

But if the circulation air is drawn from outside where it's cold, that means it's also drier air that you are pumping into your boat, while displacing some of the warmer, moister air out, so eventually the inside of your boat gets pretty dry, eliminating or at least reducing the sweating on hatch and port frames that can be so annoying as it drips on you while laying in bed.

Well yes and no... when you cook and breathe you are filling the air with moisture. The colder surfaces will cause air in contact with them to shed their air... like the morning dew. But if the humidity is very very low the condensation will be less.

[DeborahLee]

I installed a Red Dot heater used in school buses $110 connected to the hot water lines off engine. Couldn't see burning more diesel than I already was going down ICW. About $75 to install. Since I already had a Honda 2000 I got a ceramic heater $25 and used that in the evening and mornings. Had a 12V electric blanket for sleeping $45. Total $255. Only needed for a couple weeks as Bahamas were warm. Still use occasionally in Chesapeake.

[ausnp84]

Originally Posted by basssears

Interestingly the Wallas installation manual states:
"If the device uses the main tank of the boat, note that the device cannot take the fuel from the same fuel output line as the engine of the boat."
... so looks like I have to put another hole in my tank. I plan on putting in a bus heater too so doubt I would use this much while underway under power, but I have also heard stories of diesel heaters that won't run well when the engine's running when you share a fuel supply (I think the engine takes all the fuel it wants leaving not enough for the heater).

It's really not difficult fitting another outlet from your tank. From memory I bought a fuel pickup from ebay for around $30. Also gives you the peace of mind that should your master engine pickup line ever fail / get blocked, in theory you have another line available that could be emergency plumbed in.

n

[jtsailjt]

Originally Posted by Sandero

Well yes and no... when you cook and breathe you are filling the air with moisture. The colder surfaces will cause air in contact with them to shed their air... like the morning dew. But if the humidity is very very low the condensation will be less.

Isn't that what I wrote, and even explained HOW the diesel heater reduces (didn't say eliminates entirely) moisture in the air on your boat, by displacing some of that moisture filled air with outside, drier air, thus reducing (again, not necessarily entirely eliminating) condensation?

In my opinion, that's the primary advantage of a forced hot air system that draws the circulated air from outside the boat over other systems that just heat the air present inside the boat so don't contribute as much to a change in the air or, in the case of unvented propane heaters, even add to the amount of moisture present. However, any vented heater will tend to dry a boat out because the heated air will naturally rise and pass through the dorade vents or small openings around the companionway, etc., carrying moisture with it and causing outside, drier air to gradually be drawn into the boat to replace it. But a forced hot air furnace such as a Webasto or Espar heater does the drying out job much more quickly because it is actively importing cooler, drier air and pumping it into your boat at a much higher rate.

[Lizzy Belle]

Originally Posted by ramblinrod

Having a little difficulty with some of the posts suggesting that propane and alcohol is a wet heat. The product of any combustion should be vented to atmosphere to avoid carbon monoxide poisoning. // The moisture, that is most certainly a product of propane or alcohol combustion, goes up the chimney.

Agreed - but did you check the heaters I was talking about? All you can do is place them close to a hatch, and open that hatch as far as you can w/out letting too much heat escape. More or less a no-win balancing act

[leftbrainstuff]

Originally Posted by Tampabayfireman

As we all watch the latest round of storms pound the northeast, I ponder the question of installing a heater for the cooler months cruising southbound. No not talking where the snow is 2 ft deep, more for these cold snaps in Florida. I looked at the propane fired wall furnace/fire boxes vs the diesel. Looking for real world feedback




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Diesel preferred. Assumes a well integrated forced air espar type heater. We love oue espar. Very frugal on diesel consumption.

Propane might be simpler for a temp or portable solution.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[leftbrainstuff]

Originally Posted by Lizzy Belle

I'm a liveaboard, and currently only have a Zibro heater. Works just fine, but not the safest option and it does nothing to keep the boat dry (quite the opposite).

Before next winter, I'm installing a Webasto. Officially, they're diesel only, but they do fine with petroleum* as well. Which, at least here in the Netherlands (well - Belgium to be honest), is (a lot) cheaper then diesel.

*Hope that's the correct English word for it - I mean the same stuff you use for Zibro heaters.

Petro. Seriously! Do you mean kerosene?

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[mitiempo]

Originally Posted by ramblinrod

Not familiar with Wallace. Espar is the market leader, and Websasto is a significant contender.

You should be able to tap the fuel line to the engine rather than tap the fuel tank. If so, tap it after the water separator.

If you can mount the diesel heater "engine" in an area "communicating" with the auxiliary engine compartment, that ventillation system will provide supply air.

RamblinRod
Marine Service Provider]

Wallas is the quietest of the three forced air heaters by far - both inside the boat and outside. It is also the only heater of the three designed for marine use specifically - the other 2 are re-purposed truck heaters, where noise is not an issue - good but noisy.

DO NOT tap into the engine fuel line. The engine's fuel pump will pull air into the line from the heater and stall. A separate dip into the tank is easy - with the Wallas dip tube it is a simple job to drill into the tank for its installation.

Wallas 30DT uses a dual pipe exhaust. The exhaust goes out the middle and the combustion air is drawn down the exterior pipe.

The 30DT is a good choice for a 30-32' boat.