Thinking to buy a Chinese forced air diesel heater

[sailing_gal]

I know someone who just installed a chinese forced air diesel heater in their boat. There was an issue with the exhaust. Of course, the muffler they send with it was useless, so it was tossed. However, check out the temperature of your exhaust hose. In this case, it was so hot that there was concern it could catch the fiberglass near it on fire. There was an additional larger metal hose that was eventually installed over it to provide more air to cool the exhaust and separate the pipe from the nearby fiberglass.

[Oeanda]

Well I know from experience that it does get super hot. In my case there’s a lot of room back there in no man’s land, between the exhaust and anything else. But I’m going to do that. Next time I’m on the boat with the laser thermometer I’m gonna check a few spots. It does get bloody hot. And between that floppy little fuel line and the exhaust pipe, which would vaporize it if touched, there’s only 3/4” of clearance. So I hope people do not follow step one of my instruction manual and ‘fill with gasoline’.

[hpeer]

Originally Posted by Oeanda

Got the second heater and installed it tonight. Hot air blowing on the feet is goddamn blissful. Long may it last!

Attachment 251409

We have been as low as 18°F here recently (about -10°C?) and the Espar D-4 has been running flat out for quite a while. I sometimes want an entire spare heater, so I can just swap it out, just in case.

——————

I installed our D4 OVER the engine. I made a bracket that would let it slide down for service and also use small chain, belts and suspenders - literally.

The exhaust runs a couple of feet before exiting the engine room, it is well insulated and supported. At one point I have aluminum sheathing wrapped around it.

The good side benefit of this is the exhaust keeps the engine room warm. Reduces risk of freezing.

[jtsailjt]

Originally Posted by sailing_gal

I know someone who just installed a chinese forced air diesel heater in their boat. There was an issue with the exhaust. Of course, the muffler they send with it was useless, so it was tossed. However, check out the temperature of your exhaust hose. In this case, it was so hot that there was concern it could catch the fiberglass near it on fire. There was an additional larger metal hose that was eventually installed over it to provide more air to cool the exhaust and separate the pipe from the nearby fiberglass.

My Webasto came with a thick flexible insulating cover to slide on over the exhaust line for that same purpose and it does make a big difference. I wouldn't want to be without some sort of method to keep flammable things from touching the exhaust hose because it does get VERY hot.

[Oeanda]

In my case the existing pipe from the Webasto was already insulated, so for now I just slid that down over the new setup. I see it’s old and starting to fray though so l’ll have to replace that soon. I dread touching and breathing those itchy fibres.

Any ducting experts here?

One thing that makes me curious.

I hooked the Chinese heater to the old pre-existing ducting run. This ducting is 3”-ish diameter for the first 12’ or so, where it has a vent into the salon. After that point it travels another 8’ forward, but at a reduced size- about 2” diameter, to its final vent underneath my bunk.

Naturally, the hot air is hottest closest to the heater, and cools as it travels. Predictably, that last run of narrow ducting doesn’t carry much heat. I’m tempted to enlarge it- though it will mean cutting larger holes through a couple panels and a bulkhead.

It seems counterintuitive to reduce ducting size up towards the colder end of the boat where you need that heat the most. Any ideas why it would have been installed that way?

[Shaneesprit]

Originally Posted by Oeanda

I notice the clicking sound that the fuel pump makes, normally inaudible, is picked up a bit by my guitar amp. Probably speaks to my grounding more than anything though.

First world problems are so hard… I’ll take the clicking if I have to

Attachment 251410

Suspend your pump by the flexible pipework & 45’ - don’t fix the pump to the boat

[Oeanda]

Thanks. The pump itself is pretty quiet and it is actually dangling in space at the moment. The clicking I mentioned last night was more of an electronic interference issue. Probably bad grounding in my guitar and possibly in the boat as well. I clocked in at exactly 240 bpm so as long as I played guitar in time with that it was fine..

[jtsailjt]

Originally Posted by Oeanda

In my case the existing pipe from the Webasto was already insulated, so for now I just slid that down over the new setup. I see it’s old and starting to fray though so l’ll have to replace that soon. I dread touching and breathing those itchy fibres.

Any ducting experts here?

One thing that makes me curious.

I hooked the Chinese heater to the old pre-existing ducting run. This ducting is 3”-ish diameter for the first 12’ or so, where it has a vent into the salon. After that point it travels another 8’ forward, but at a reduced size- about 2” diameter, to its final vent underneath my bunk.

Naturally, the hot air is hottest closest to the heater, and cools as it travels. Predictably, that last run of narrow ducting doesn’t carry much heat. I’m tempted to enlarge it- though it will mean cutting larger holes through a couple panels and a bulkhead.

It seems counterintuitive to reduce ducting size up towards the colder end of the boat where you need that heat the most. Any ideas why it would have been installed that way?

Larger diameter ducting results in increased flow to that area but whether it’s worthwhile is your call, depending on how many bulkheads you have to pass through and any tight spots that may have trouble accommodating larger diameter ducting and how much heat you need up there. I had that problem with the duct to my forward shower so had to downsize the duct diameter up there. Unless I close off my main saloon duct, barely a trickle of heat makes it past that and up to the forward shower but if I close off the main saloon outlet, even with the smaller ducting, it gets very warm up there. But unless I have guests aboard I don’t care if that forward shower is warm and I usually want max heat in main saloon or aft head so that forward outlet is normally closed off. I have the type grills that can be shut off on all my outlets and they are rarely all open at once. You just have to remember to never close all the outlets at one time.

If you didn’t have the ability to close or partially close some outlets then I can understand why it could be an advantage to try to balance the flow by using smaller ducting leading to the smaller forward cabin that’s like a branch off of the main trunk duct, but since you do have the ability to close off or modulate the flow to various outlets, then I don’t think there’s any downside to increasing the diameter of the ducting to the forward cabin if you want to and if there’s room for the larger diameter ducts.

[Oeanda]

Realization- to change the metronome tempo I just turn the heater down.

[JeffBurright]

I just picked one of these up and am noodling through the install. On the fuel supply, has anyone tried just installing a reducing tee in their main fuel supply hose between the boat's fuel tank and the diesel engine before it gets to the engine fuel filter? Would there be a good reason to not do this and do a separate fuel stand pipe into the main diesel tank instead? There's a nagging feeling in my brain saying it could be a bad idea, but I can't logic out how.



I also have the 15L tank that came with the heater, but I'd rather save the space if I can. I'd also have to pay attention to the fuel gauge to make sure I don't empty my main tank while at anchor.

[Sailing August]

Get yourself a good fire extinguisher to go with it.

[Chayal]

I can vouch for these heaters. They work very well considering the price.

I prefer my Dickinson/planar combo, but know many people who have ran these units with success and nothing terrible to say about them… surprisingly. I would ensure you can get spare parts like glow plug, new master switch etc.

The key is in the installation, I installed one and apart from working some bugs with the fresh air inlet, watch your length + bends on exhaust. Watch for the drain on the muffler if your running it, this should be the lowest section of exhaust so it can drain. Basically the muffler can only be installed in 1 position to properly drain. It’s sneaky and no mention in the poor provided instructions.

I would be safe to assume the negative comments about these is just information being parroted from one mouth to the other, with minimal knowledge or actual experience with these heaters.

Then again, you get what you pay for.

[Chayal]

Originally Posted by Sailing August

Get yourself a good fire extinguisher to go with it.

You should have a good fire extinguisher regardless of the brand.

Same with a co2 alarm.

[Shaneesprit]

Throw the exhaust muffler in the bin, don’t bother fitting it on a boat unless you can seal it, probably by welding around the entire flanges. The drain in the exhaust will give you exhaust fumes in the cabin - These are meant to be installed underside of Vans so outside. I have tried crimping the flanges with limited success.
If you fit an exhaust drain you need to pigtail it so that it’s full of water and doesn’t pass fumes.

On the ducting question raised your first duct is too large, ideally you want all of the ducts to be the same size or in effect to have the same back pressure, meaning the closer to the heater the smaller the duct would be.
Might be worth having 4 ducts of equal size rather then making any existing ones bigger.
Like wise any additional length or bends mean that warm air is less likely to reach that duct unless they all have the same length and bends.

I am beginning to feel the pressure of this thread and the need to get my heater running again in the future.

Why the fire extinguisher quotes? I mean need that anyway for insurance purposes, but has anyone actually had a fire confirmed to be from a diesel heater?

[Oeanda]

Yes we have several fire extinguishers and a couple CO detectors.

Besides a lot of the general scary safety warnings that people are fond of posting, I did find one online report of two deaths from these heaters when used in vehicles. One was carbon monoxide poisoning and the other was a fire caused by fabric igniting in the vicinity of the heater. My ducting run is mostly all insulated now, and the same ducting layout (minus the insulation) was used for decades so hopefully won’t bring any surprises unless the heater itself blows up. I haven’t found any obvious reports of that so far.

The air blowing out in the salon at the moment is hot enough to burn my feet a little if I’m too close. I could easily imagine it melting something. Presumably no different though than if I still had the Webasto installed.

I will look into expanding the size of the forward run of ducting. Yes we do have closing vent covers on the outlets. It’s wonderful to be able to easily focus the heat in chosen parts of the boat, which is something we have not been able to do with any of our various other heating systems. The head gets toasty warm, and quickly dries after showers. The ducting run itself is warm of course and therefore heats some recesses of the boat that to date have been perpetually damp. This is making the boat happy.

A couple side notes. The second heater I bought, although supposedly being the same purchase, was another mix of parts. Different (better) LCD controller although it did fit the same connection. Different manual. A different fuel pump, configured (based on its shape) to pump in the opposite direction to the first one we had. No arrow on it to show fuel flow direction either.

The eBay supplier continues to appear keen to replace any faulty parts, including (I think) an entire replacement heater if i ask for one. There’s a bit of a language barrier so I can’t say that I’m 100% clear about that last one even though they seem to keep saying ‘yes’. But for the record there does seem to be a certain amount of customer support at least