Espar return air puzzle

[Portage_Bay]

Before we get started, yes I know it's really Ebersparcher. In the USofA they are sold as Espar.

Old D8 unit. Return air is drawn from the guest cabin and the engine room. Thinking of blocking off the return air duct in the engine room unless someone can tell my why there's a good reason to draw engine room air and send it to the living areas. I can't think of one. I can think of plenty of reasons why it's a bad idea.

Discovered this in a new-to-me boat when troubleshooting the Espar.

And while I'm at it drawing return air from the guest cabin is not a great idea. Not enough air exchage in the main cabin where we want more heat more often than the guest cabin.

Looks like I've got some duct work to do after I get the old D8 running agins.

 

[SteveK]

wow, I wonder if the intent was to heat the engine room and done assbackwards. Not a good idea if only for ER smells encouraged into the living space.

 

[Bmarler]

I always preferred to pull in the air from outside. The heat loss from cold air intake is not noticeable.
You also get lower humidity, and positive pressure inside the boat makes it less drafty feeling.

 

[av8r]

My system has a “y” in the air supply to the heater, part of it is return air from the floor of the salon and part of it is fresh air from the lazarette. Both ducts have adjustable louvers so I could change the balance of air drawn into the heater but I’ve never changed them from wide open.
As I recall the old D8 manual talked extensively about making sure there was no airflow restriction in either the supply side or the outlet side.

 

[Portage_Bay]

Thanks to all who have replied. I agree. The engine room return air duct will be blocked.

 

[Marco Flamingo]

I can tell you what I've done for ducting on the Espar and identical units. I'm not saying it's right, just that it works. When I installed an Espar D2, I found an installation manual that had the length limitations for intake and exhaust duct, including subtractions for Ys, Ls, and registers. Even the registers have resistance that, when figured into the calculation, would shorten the recommended duct run by a foot or so. Now, I can't find that info on the net, other than Espar limits the combustion intake to 2 meters and the exhaust to 2 meters (including the intake silencer and exhaust muffler). As I recall, the recommended minimum length of the heat duct was surprisingly short, also something like 2 meters each side, with deductions for Ls and even bigger deductions for Ts.

Knowing that the length of ducting/exhaust effects the efficiency and maybe the maintenance, I looked to keeping both of them as short as possible. My latest heater installation is in the engine room with no ducting at all on the fresh air heat intake. Straight out of the engine room. Assuming Espar allows 4 meters total duct length, I can use all that length just on the distribution side. I've read here several times about concern of "bilge odors" being distributed, but never a real discussion of what those odors are. Holding tank? Diesel? Wouldn't the concern (and the fix) be the source of those odors? I guess if I suddenly smelled smoke/diesel/poop I would need to fix that. The engine room air intake for the heater would still be fine. Maybe I should claim that having the air intake in the engine room is a safety feature!

My combustion air also comes from the engine room. I also don't have much length on the intake ducting. Just enough to attach the air intake silencer. The combustion intake makes a whining/whistling noise when running on high. Since it's in the engine room it is hardly noticeable at anchor, but with the silencer it really is silent in the cabin. The exhaust ducting has a DIY muffler and >2m of stainless pipe to a through hull, all wrapped in lagging. There are a couple places in Ballard that will fabricate fancy lagging relatively inexpensively if you have a pattern. Otherwise, fiberglass tape made for wrapping headers or, probably less expensive, 2" wide fiberglass tape from Amazon and SS bands.

An exhaust muffler is really required, not so much for you but for your neighbors. Lots of people say that their generator is really quiet (because the exhaust is pointing at others), but a good little muffler on a diesel heater actually is quiet. I run mine in the marina and nobody can hear it. My fuel pump makes a tick, but it is wrapped in foam and suspended from a rubber strap, so it can only be heard when sitting on the head, which is next to the heater.

There would still be some benefit for drawing engine room air even if the heater itself is outside of the engine room, assuming that the engine room has sufficient fresh air. The fresh air would provide some positive pressure in the heated cabin and help reduce humidity. If your system draws air from both the guest cabin and the engine room using a T fitting, I'd probably eliminate the T and just draw from the engine room.

 

[SeaDogAK]

I would be far more concerned about carbon monoxide than odors, if my heater drew air from the engine room. That would be an absolute no from me, from a life safety standpoint.

 

[Portage_Bay]

That's my main concern as well. CO risk with diesel is minor but real.

I would be far more concerned about carbon monoxide than odors, if my heater drew air from the engine room. That would be an absolute no from me, from a life safety standpoint.

 

[Marco Flamingo]

Yes, CO is a minor concern with diesel. I'm very sensitive to diesel exhaust, so I would smell it. Or one of my CO detectors would go off either in the engine room or the cabin. They are also extremely sensitive. The one time I smelled diesel exhaust, it was the exhaust from the diesel heater that was leaking. I doubled the hose clamps and used a high-temp sealant.

I wouldn't have a diesel heater onboard without detectors, as the heater itself is likely to be the source of CO. Better to have a diesel heater in the engine room from a life safety standpoint?

 

[SeaDogAK]

Yes, CO is a minor concern with diesel. I'm very sensitive to diesel exhaust, so I would smell it. Or one of my CO detectors would go off either in the engine room or the cabin. They are also extremely sensitive. The one time I smelled diesel exhaust, it was the exhaust from the diesel heater that was leaking. I doubled the hose clamps and used a high-temp sealant.

I wouldn't have a diesel heater onboard without detectors, as the heater itself is likely to be the source of CO. Better to have a diesel heater in the engine room from a life safety standpoint?

Your boat, your call. I wouldn’t do it.

 

[Caballero II]

I can tell you what I've done for ducting on the Espar and identical units. I'm not saying it's right, just that it works. When I installed an Espar D2, I found an installation manual that had the length limitations for intake and exhaust duct, including subtractions for Ys, Ls, and registers. Even the registers have resistance that, when figured into the calculation, would shorten the recommended duct run by a foot or so. Now, I can't find that info on the net, other than Espar limits the combustion intake to 2 meters and the exhaust to 2 meters (including the intake silencer and exhaust muffler). As I recall, the recommended minimum length of the heat duct was surprisingly short, also something like 2 meters each side, with deductions for Ls and even bigger deductions for Ts.

Knowing that the length of ducting/exhaust effects the efficiency and maybe the maintenance, I looked to keeping both of them as short as possible. My latest heater installation is in the engine room with no ducting at all on the fresh air heat intake. Straight out of the engine room. Assuming Espar allows 4 meters total duct length, I can use all that length just on the distribution side. I've read here several times about concern of "bilge odors" being distributed, but never a real discussion of what those odors are. Holding tank? Diesel? Wouldn't the concern (and the fix) be the source of those odors? I guess if I suddenly smelled smoke/diesel/poop I would need to fix that. The engine room air intake for the heater would still be fine. Maybe I should claim that having the air intake in the engine room is a safety feature!

My combustion air also comes from the engine room. I also don't have much length on the intake ducting. Just enough to attach the air intake silencer. The combustion intake makes a whining/whistling noise when running on high. Since it's in the engine room it is hardly noticeable at anchor, but with the silencer it really is silent in the cabin. The exhaust ducting has a DIY muffler and >2m of stainless pipe to a through hull, all wrapped in lagging. There are a couple places in Ballard that will fabricate fancy lagging relatively inexpensively if you have a pattern. Otherwise, fiberglass tape made for wrapping headers or, probably less expensive, 2" wide fiberglass tape from Amazon and SS bands.

An exhaust muffler is really required, not so much for you but for your neighbors. Lots of people say that their generator is really quiet (because the exhaust is pointing at others), but a good little muffler on a diesel heater actually is quiet. I run mine in the marina and nobody can hear it. My fuel pump makes a tick, but it is wrapped in foam and suspended from a rubber strap, so it can only be heard when sitting on the head, which is next to the heater.

There would still be some benefit for drawing engine room air even if the heater itself is outside of the engine room, assuming that the engine room has sufficient fresh air. The fresh air would provide some positive pressure in the heated cabin and help reduce humidity. If your system draws air from both the guest cabin and the engine room using a T fitting, I'd probably eliminate the T and just draw from the engine room.

What he said. On my GB, drawing fresh air for heating and combustion makes sense given distance constraints because the fresh access from the ER as more than adequate, and so lessens the amount of ducting in an already crowded er space. We don't care what air we burn for combustion. Mufflers are helpfull, mostly for your neighbors.

I guess we eliminated any noticeable odor in the er when we switched to fresh water heads, so has not been a problem.

 

[Caballero II]

What he said. On my GB, drawing fresh air for heating and combustion makes sense given distance constraints because the fresh access from the ER as more than adequate, and so lessens the amount of ducting in an already crowded er space. We don't care what air we burn for combustion. Mufflers are helpfull, mostly for your neighbors.

I guess we eliminated any noticeable odor in the er when we switched to fresh water heads, so has not been a problem.

And what I meant was drawing fresh air from the engine room, because there's plenty there.

 

[Caballero II]

I would be far more concerned about carbon monoxide than odors, if my heater drew air from the engine room. That would be an absolute no from me, from a life safety standpoint.

Umm (?), what CO, from what source? Assuming you are diesel.

 

[SeaDogAK]

Diesel exhaust can contain enough CO to give a lethal dose, even though it’s less than a gas engine.

 

[Portage_Bay]

From the U.S. Department of Health and Human Services Diesel fumes do kill I do recall years ago having to work when diesel exhaust was blowing my way and getting very ill.

However as Marco says

Yes, CO is a minor concern with diesel. I'm very sensitive to diesel exhaust, so I would smell it. Or one of my CO detectors would go off either in the engine room or the cabin. They are also extremely sensitive. The one time I smelled diesel exhaust, it was the exhaust from the diesel heater that was leaking. I doubled the hose clamps and used a high-temp sealant.

I wouldn't have a diesel heater onboard without detectors, as the heater itself is likely to be the source of CO. Better to have a diesel heater in the engine room from a life safety standpoint?

And along with his remarks regarding duct length I may re-think this.

But first I've got to get the ancient Espar running again if I can. (creating thread drift here on a thread I started) it could be time for Chinese diesel heaters. I have ordered one for my shop to test it out.

 

[SteveK]

From the U.S. Department of Health and Human Services Diesel fumes do kill I do recall years ago having to work when diesel exhaust was blowing my way and getting very ill.

However as Marco says And along with his remarks regarding duct length I may re-think this.

But first I've got to get the ancient Espar running again if I can. (creating thread drift here on a thread I started) it could be time for Chinese diesel heaters. I have ordered one for my shop to test it out.

I had an espar that I got running again, for a short time. Closer inspection saw that the circuit board was replaced in the past.
Going to suggest stop wasting your time. It is past the best before due date.

 

[Portage_Bay]

I'm tempted to toss it and start over. But a new Espar unit is $8K. To go with the Chinese units it would take two heaters to do the job which means more ducting, another exhaust port, another fuel setup, another power supply. Not anything I'm looking forward to doing. Hard to say which is the lesser of two evils.

I had an espar that I got running again, for a short time. Closer inspection saw that the circuit board was replaced in the past.
Going to suggest stop wasting your time. It is past the best before due date.

 

[Bmarler]

I'm tempted to toss it and start over. But a new Espar unit is $8K. To go with the Chinese units it would take two heaters to do the job which means more ducting, another exhaust port, another fuel setup, another power supply. Not anything I'm looking forward to doing. Hard to say which is the lesser of two evils.

the d8 is a very robust heater. i would definitely try to get it operational if i were in your position.

 

[Portage_Bay]

It's running! I always tell everyone else when troubleshooting to start with the simple things. Start at t one of the system or the other. Don't jump in the middle with assumptions in hand. It was starved for fuel. I should learn to listen to my own advice. Three possibilities.

1 - Plugged filter. Yeah, I know, it's clear. Just check and if in doubt change it.

2 - Low fuel. Me thinks this fuel pickup is done right, well off the bottom of the tank so the heater can't run the fuel too low.

3 - Pump was not anywhere near the recommended up angle. A bracket came loose. Easy fix.

I put a 5 gal can of clean diesel next to it and ran a hose straight to the pump. New can, new diesel so I felt safe in bypassing the filter.

the d8 is a very robust heater. i would definitely try to get it operational if i were in your position.

 

[Bmarler]

It's running! I always tell everyone else when troubleshooting to start with the simple things. Start at t one of the system or the other. Don't jump in the middle with assumptions in hand. It was starved for fuel. I should learn to listen to my own advice. Three possibilities.

1 - Plugged filter. Yeah, I know, it's clear. Just check and if in doubt change it.

2 - Low fuel. Me thinks this fuel pickup is done right, well off the bottom of the tank so the heater can't run the fuel too low.

3 - Pump was not anywhere near the recommended up angle. A bracket came loose. Easy fix.

I put a 5 gal can of clean diesel next to it and ran a hose straight to the pump. New can, new diesel so I felt safe in bypassing the filter.

Glad to hear it. Like I mentioned, those are very robust heaters and worth the effort to get running.

 

[MVCalypso]

But first I've got to get the ancient Espar running again if I can. (creating thread drift here on a thread I started) it could be time for Chinese diesel heaters. I have ordered one for my shop to test it out.

Spring last year I went through the "Fix the Espar" or try the cheap Chinese diesel heaters (CDH) exercise...

WARNING - A CDH heater can (and is likely to try to) kill you!
I'm not being melodramatic. CDH manufacturing quality control is horrid.

I had an Espar D3L in my boat for 30+ years. Two expensive repair attempts last yer and it still would not work right; some key parts no longer available. I liked the Espar. It was one of the few pieces of equipment that has given 98% trouble free service for 30 years - in a marine environment.

The plan was to remove the Espar, replace the heater unit itself and reuse most all of the other (already installed) components (ducting, fuel lines, exhaust runs, thru hull exhaust fitting etc.).

Even so, I couldn’t overlook the pricing for the CDH units so I bought one to try it out. I was prepared to loose $99 for the heater kit if the experiment went bad.

Potentially fatal problem #1:
As the heater arrived, there was a silicone glow plug cap which was not inserted/seated into the heater body. That would let CO mix from the combustion chamber into the heater warm air output. As delivered from the factory, the heater would have pumped CO into the living spaces. The fix was simple (correctly reassemble the heater), but the danger was high.

The next step was to test run the CDH in the shop - that all went fine & the heater showed no problems (I thought). Then I installed the CDH into the boat...

Potentially fatal problem #2:
On first start up, after a few minutes when it got up to operating temp (3 of 6 heat setting) there appeared a lot of smoke from the base of the heater & from the exhaust wrapping.

The heater was very quickly shut down. I have no sense of humor when it comes to potential fires on a boat. Smoke coming from the engine room gets my attention.

Once I realized I did not have a fire situation, I began thinking that this is something burning off from the CDH. But whatever it is is likely to be from the boat install as it did not do this during the test runs.

I got online and started asking questions on CDH forums. I was quickly told that some heaters come with a rubber (not silicone) gasket between the heater base and the mounting plate. In fact, there are videos online of that damn rubber gasket catching fire! Note: The combustion exhaust port is HOT at high heat: 572F !

I solved this by removing the heater and replacing the rubber gasket with the silicone one from my prior Espar.

Other problems (Not potentially fatal, just very, very irritating):
a) The CDH heaters do not shut off when the thermostat temp is reached. They just throttle back - so the temp inside just keeps climbing.
b) The controls provided with CDH heaters are close to incomprehensible. Each one is slight different re user interface and settings - and the poorly translated manual did not match what the control actually did. I eventually replaced the internal heater CPU board and the control with a 3rd party, open source controller which cost 1.5x the heater price.
c) The various parts supplied with the heater kits are junk. Fuel hose that is so soft the fuel pump pulses just expand the hose instead of traveling to the heater. Exhaust hoses that appear to have been made from Al foil chewing gum wrappers. etc. etc. etc. The only reason The installation works is that I reused all the quality parts from the prior espar install. Those parts far exceed the cost of the CDH heater kit.

I have it all working, the problems are solved. But that $99 (literally delivered to my front door by amazon) heater kit required around an additional $800 in parts and it tried two different ways to kill me. Even at minimum wage for my time, I think a new Espar would have been the better deal.

When the CDH eventually dies (or just looks at me cross eyed), it will not be replaced with another CDH.

I strongly recommend that one think long and hard before deciding to be seduced by the pricing of a CDH. The price of a new Espar or Webasto can quickly come to not look so expensive.

 

[Portage_Bay]

I've done my due diligence on the Chinese heaters and was aware of the problems you found except for the glow plug not being sealed. Thank you for bringing that up. I've bought enough inexpensive Chinese hardware to know you don't just push the 0/1 button. You have to do a thorough inspection, there will likely be things to fix right out of the box.

I've purchased a Chinese heater to warm my shop and work out the kinks if I decide to go that route on the boat. I don't expect it to work out of the box, shop or boat. I do expect to replace the fuel line, about $15, Extend the exhaust, what comes in the kit is too short, about $16. Wrap the exhaust another $15. All in for the shop try out about $145. To install in the boat I'd use higher quality exhaust components. So a bit more yet for boat installation but no where near $800.

I'd need a pair of them to do what the 8D does and at cost of $800 each that's still a bargain compared to the $8000 replacement cost for the 8D.

If/when the 8D dies it won't be replaced with another Espar or a Webasto. Cost aside there are better ways to heat a boat. I've given this a lot of thought.

Previous boat had a Hurricane hydronic system. More comfortable heat, better zone control, 'real' thermostat control, heated domestic water, used engine heat when underway and could easily be plumbed in to pre-heat the engines, drew less electrical power than the Espar does. I could pull the hoses through the existing ducting. Wiring runs for the thermostats might be a challenge. I spent enough time and $$ fixing the botched install of the Hurricane I am well aware of what is needed and compared to those apes an expert.

If I wanted to take advantage of existing ducting to install another forced air system and willing to spend The $$$ I'd go with Wallas. Compared to Espar or Webasto. Silent and smaller. Clean enough and safe to install in the living space. Forward cabin is a challenge to heat, a Wallas unit would solve that problem nicely.

If I could get it by my sweetheart I'd put in a drip burner in the saloon. Silent radiant heat.

Potentially fatal problem #1:
As the heater arrived, there was a silicone glow plug cap which was not inserted/seated into the heater body. That would let CO mix from the combustion chamber into the heater warm air output. As delivered from the factory, the heater would have pumped CO into the living spaces. The fix was simple (correctly reassemble the heater), but the danger was high.

I have it all working, the problems are solved. But that $99 (literally delivered to my front door by amazon) heater kit required around an additional $800 in parts and it tried two different ways to kill me. Even at minimum wage for my time, I think a new Espar would have been the better deal.

When the CDH eventually dies (or just looks at me cross eyed), it will not be replaced with another CDH.

 

[koliver]

In my first few years of ownership, my D7L Espar heater cost more to maintain than my two 150hp propulsion engines and my 4kw Genset, combined.
What I learned about the Espar in that saga boils down to the original design of the unit being for a bus, in a very different environment than our boats, and that cold fuel is unwelcome in the heater. Eventually, I found that mine worked well after everything was warmed thoroughly, but startup after being left a few days in cold weather was near impossible.
Long after I had given up on this unit I had a long conversation with a former Espar technician, who put all of my observations in perspective, essentially agreeing that the old D7L technology had never been intended for a marine environment, nor for the usage typical of pleasure boating in Vancouver winters.
When you have the opportunity, choose something else.
In my case, space heating in cold weather is provided by my diesel stove in the galley (down in the layout of my boat).
As for the air supply, mine was a single 4" duct from the saloon, just above the floor, so a short run of pipe to the heater located just below in the ER. Combustion air was drawn directly from the ER.
Heated air was distributed through the boat by a 4" pipe exiting the heater, branching to smaller pipes as it got further from the source, the smallest looked to be 2.5" at the ends of the runs.
Sourcing the "cold" air in the ER may have been to help deal with the starting issues, to give the heater the warm ER air after the main engines had been run for a while and thus get better performance from the heater.
Unless you have a serious problem with the exhaust system on your propulsion engines, all of their products of combustion, except heat, will go out the exhaust, so drawing from the ER should be safer than drawing from the lazarette, where a "Station wagon" effect may draw some contaminated air.

 

[Portage_Bay]

koliver,

I agree with what you are saying. As I said above, the D8 won't be replaced if / when it dies. And I'm not paying someone thousand$ to keep it running. There are better options to heat a boat. The only thing I think you missed, and it is nit-picking, is the D8 is larger than the D7.

Projected ownership of this boat is 2 - 3 yrs. I hope to keep it running that long.

 

[MVCalypso]

Hi,

After almost a year since I did that project, it still causes an emotional reaction from me. Sorry if I was in rant-on mode.

Taking the the approach that a CDH is a kit of sorta related parts and treating it's operation like it's a coiled rattle snake, is prudent.

BTW, if you don't mind fiddling, and want good (including remote) control of a CDH, you may find the afterburner controller of interest.

Thanks for the ref to the Wallas, I've not looked into them. When the CDH does, I'll check them out.

 

[Portage_Bay]

As with any equipment support is as important, perhaps more important than the equipment itself. In that respect if you go Wallas think about Scan Marine in Seattle. For me if I go forced air it will be one extreme or the other Chinese, cheap, I'm on my own and questionable quality. Or Wallas, install, sit back and enjoy the comfort.

I'm aware of the afterburner controler. If need be I'll look into that. In the past year or so the controls on the cheap heaters have gotten more sophisticated. The one I purchased has an iPhone or Andorid app. Maybe it's more than simple on/off. We'll see.

There's another add on controller worth looking into as well by Bureck.

Experimenting with all of this in the shop is a pretty painless way to learn.

No need to apologize for the rant. It was pretty minor. I could do the same about the apes that installed the Hurricane on my previous boat. But I won't. Takes me too long to settle down after I get going.

Hi,

After almost a year since I did that project, it still causes an emotional reaction from me. Sorry if I was in rant-on mode.

Taking the the approach that a CDH is a kit of sorta related parts and treating it's operation like it's a coiled rattle snake, is prudent.

BTW, if you don't mind fiddling, and want good (including remote) control of a CDH, you may find the afterburner controller of interest.

Thanks for the ref to the Wallas, I've not looked into them. When the CDH does, I'll check them out.