Diesel heaters?

[kidjedi]

Originally Posted by martin300662

One of the biggest issues with the Chinese vs Webasto/Eberspacher is the physical size. The Chinese units are around double the dimensions for the same output.

Are you sure about that? I am under the impression that the Webasto is actually larger. The Chinese unit I just installed was smaller than a shoe box (see attached photo). This was an "8kw" unit (I believe actually 5kw and comparable to a 5kw Webasto). It would be incredibly impressive if the Webasto/Eberspacher could put out this much heat at half the size. I'm also not sure where they'd stuff all the components if the whole unit was smaller than a tissue box.

[Eric F]

Thanks for all of your input and suggestions. McK's videos are great. Hopefully 5kBTU is sufficient. If not, I'll add a second.

I will use a 1m metal flex-duct to feed into the cabinet, and have branch-offs for the AS's ductwork. When operating correctly, the output temp should be the same as the suburban natural gas heater. I wonder about adding some fins (ideas anybody?) to the flex-duct to drop the temperature a bit.

[kidjedi]

Originally Posted by Eric F

Thanks for all of your input and suggestions. McK's videos are great. Hopefully 5kBTU is sufficient. If not, I'll add a second.

I will use a 1m metal flex-duct to feed into the cabinet, and have branch-offs for the AS's ductwork. When operating correctly, the output temp should be the same as the suburban natural gas heater. I wonder about adding some fins (ideas anybody?) to the flex-duct to drop the temperature a bit.

FWIW, I have been using rigid ducts. Their convenience will really depend on the kind of access you have, but they don't get smashed or fill up with dirt and debris like the flex tubes. I have dismantled enough old RVs and trailers to see what the ravages of time do to flexible and soft HVAC ducting. That said, with smooth insides, the rigid ducts do transmit more *noise* from the source (not much of an issue with the diesel heaters). I am in the process of doing the ducting for my GMC TZE and I am actually running my water lines inside the HVAC ducts. This will keep them warm in freezing temps and also makes for easier pulling if they ever need to be replaced (the ducting acts as a conduit). It also mitigates the number of places water could potentially leak (only at the ducting joints). The water lines do not run close to the heater, so there is time/distance for a temperature drop before the sections that contain water lines. The heat output of the diesel heater really is quite high; seems higher than the Suburban furnace at the source.

[martin300662]

Originally Posted by kidjedi

Are you sure about that? I am under the impression that the Webasto is actually larger. The Chinese unit I just installed was smaller than a shoe box (see attached photo). This was an "8kw" unit (I believe actually 5kw and comparable to a 5kw Webasto). It would be incredibly impressive if the Webasto/Eberspacher could put out this much heat at half the size. I'm also not sure where they'd stuff all the components if the whole unit was smaller than a tissue box.

Yes, there are plenty of comparison photos online. As for real experience, I have a Nissan NV200 microcamper, many folks fit a Webasto/Eberspacher under the passenger seat, the Chinese versions don't fit.

[kidjedi]

Originally Posted by martin300662

Yes, there are plenty of comparison photos online. As for real experience, I have a Nissan NV200 microcamper, many folks fit a Webasto/Eberspacher under the passenger seat, the Chinese versions don't fit.

In the interest of "good information," the Webasto Air Top EVO 40 dimensions are 16.65" long x 5.82" wide x 6.37" tall.

The Chinese 8K unit in the photo I posted above is < 15.5"x5.5"x5.5".

I'm not saying the Chinese heater compares in output, quality, etc., but the Chinese heater is slightly smaller, so the Webasto certainly is not half the size.

I think you may be confusing these little units with the giant units that have the actual fuel tank mounted inside the heater housing.

[martin300662]

There is no confusion on my part, just real data, not internet searches.

A Webasto Thermo Top Evo fits under the passenger seat on a NV200. The Chinese knock-offs look similar and using a 'if it walks like a duck, and quacks like a duck, it is probably a duck' logic should be the same. They are 1/10th the cost so I ordered one. I did not fit. I got rid of it and bought a Webasto Thermo Top and it fits.

I am not claiming the Chinese ones don't work - I bought one and would have happily used it if it fitted in the space available. But like most Chinese copies they look the same (or rather similar) and work the same (or rather similar) but they are not the same.

I am not comparing all Chinese models, or all Webasto/Eberspacher models but the Webasto Thermo Top is around 2/3rd of the size of the Chinese model I bought from Aliexpress.

[richard5933]

The confusion is likely due to the fact that there is not just one Chinese knock-off these. There are many companies making them, and to make it more confusing the names on them changes frequently. All the various versions look just like the authentic units on first glance, but on closer inspection they are all different. And they are all different in different ways.

A friend of mine was working at one time to install one in a bus conversion, and the problem he ran into with the knock-off was the plastic parts used near the exhaust necessitating extra clearance and ventilation space. I believe he ended up using a real diesel heater since it allowed tighter clearances and was thought to be safer.

[kidjedi]

Originally Posted by martin300662

There is no confusion on my part, just real data, not internet searches.

I'm not sure why you keep pushing back on this. I am not speaking from "internet searches." I am holding the product in my hands. I have installed three so far.

I do think (know) the Webasto/Eberspacher units are of much higher quality and backed by MUCH better service (the Chinese ones are not backed at all).

Originally Posted by martin300662

I am not comparing all Chinese models, or all Webasto/Eberspacher models but the Webasto Thermo Top is around 2/3rd of the size of the Chinese model I bought from Aliexpress.

So... the Chinese heater you bought on Aliexpress was bigger than a Webasto, but obviously that doesn't mean they all are. The one I referenced and for which I provided a photo is definitely *smaller* than a Webasto/Eberspacher.

I am pushing back on this information for those who are making decisions about what to put in their vehicles/trailers. Size doesn't need to be the reason to *not* go with the Chinese heaters. Safety and reliability are definitely still considerations.

[kidjedi]

Originally Posted by richard5933

The confusion is likely due to the fact that there is not just one Chinese knock-off these. There are many companies making them, and to make it more confusing the names on them changes frequently. All the various versions look just like the authentic units on first glance, but on closer inspection they are all different. And they are all different in different ways.

Right. The problem with all these "ultra-cheap" Chinese products is that there are so many versions, some from the same manufacturer and just rebranded, but some copied, and often not copied well. When each copy is just going for "cheaper," there is a quickly diminishing point of return on "if it's worth it."

FWIW, I bought three different "brands" from different sellers on Amazon (prices varying by about $40-50), and they all turned out to be identical (I even removed the housing and everything inside was the same).

Originally Posted by richard5933

A friend of mine was working at one time to install one in a bus conversion, and the problem he ran into with the knock-off was the plastic parts used near the exhaust necessitating extra clearance and ventilation space. I believe he ended up using a real diesel heater since it allowed tighter clearances and was thought to be safer.

"Thought to be safer" is absolutely a consideration. I definitely think these need to be utilized with additional care and consideration for the fact that they are using fuel to create heat, and probably not super-regulated as far as safety goes.

[suncoasteng]

Anyone tried one of these? Wondering what exhaust pipe temperature gets up to, seems like a double exhaust tube is necessary.

https://www.vevor.com/diesel-heater-...&utm_medium=US

[richard5933]

Originally Posted by suncoasteng

Anyone tried one of these? Wondering what exhaust pipe temperature gets up to, seems like a double exhaust tube is necessary.

https://www.vevor.com/diesel-heater-...&utm_medium=US

Are you thinking of using this inside or outside your trailer?

For mounting inside, a 'regular' diesel heater would be much more simple to install, even though it's in multiple pieces. The form factor of these units would seem to complicate installing inside, requiring a much larger space for the install. I'm not even sure that they're designed to be used that way. The videos I found about them largely show their use outside with the heated air being routed back to the interior.

[Eric F]

Those units are a combination of a "Chinese diesel heater" and a fuel tank. In our 81 westy I just buy the heater unit separately and mount the fuel tank somewhere myself. For the westy, I used a outboard fuel tank that goes in our roof carrier.

I love those heaters, and I'm in the process of mounting one through the floor just behind the driver's seat of my 74 argosy mh. That way, the exhaust is completely exterior of the vehicle.

I'm thinking of mounting the fuel tank in the rear exterior with three 1/4-20 bolts and wing nuts so that they can be removed in the summer.

Not that they are only 4kw, so you might need a second one for serious winter use.