Diesel heater fan only

[Kevinm]

Im wondering if any of the diesel heaters on the market, be it Chinese or planar etc. or aftermarket controllers (afterburner etc) are capable of running the fan without heat?

Im wanting to use it for creating positive pressure to keep dust out of my truck canopy (while driving) and possibly just ventilation in warm or rainy weather

I would be using a similar filter set up as pictured to filter the dust out. Also any insight into which MERV level i should get and if this is practical. ie not too restrictive?

The goal is to just keep things from getting dusty. I imagine a MERV 5 or even lower would accomplish that but i have zero expierence

 

[Dave in AZ]

Good idea

 

[Victorian]

Autotherm does have the fan function

 

[86scotty]

My Lavaner has that function as well.

 

[Kevinm]

Unless the heater uses some kind of brushless motor...
If the controller has no option for manually running the fan.
Making the fan run on its own, just add switch and separate electric source to the fan circuit.

Without seeing a specific heater to know its specific configuration.
Probably best using at least two pole form "C" switch to keep the heater controller 100% isolated from the separate source.
A three pole would be better. Using the third pole to prevent the heater trying to run when the fan is switched to manual control.

I actually just finished taking my Chinese heater apart to see it the motors wires were exposed so i could do just that. I was happy to see its quite easy to do. I was thinking to use a diode to prevent back feeding power to the controller. However i have no idea what to order or if there is the right diode for the job out there. I plan to use a rheostat for adjustability of the fan fyi

I suppose i could use a relay but if a diode would do the trick that seems much simpler. Im good with basic DC power but i have no idea what to order when it comes to diodes. A quick look on digikey left me with more questions than answers.

I actually do want some diodes for a similar purpose on other parts of my truck build, so if someone could point me in the right direction it would be appreciated

 

[NatersXJ6]

This is completely a guess, but my guess is that most of the small Diesel Heaters / Chinese Diesel Heaters don’t have a fan powerful enough to draw through that filter or create much of a positive pressure in a camper sized space. It would probably be something you could measure with a decent manometer, or just do because you want to, but theory and reality are probably far apart in this case.

 

[Kevinm]

Yeah all i can do is guess at this point. I feel like it doesn’t take much positive pressure or flow to stop dust from coming in. The restriction from the filter is the biggest variable in my mind.

Regardless if i use CDH to keep dust out or not i will be setting up my diesel heater the same way. The only thing i would be adding to the system is the filter, which i can do some experiments in the garage before i install in truck and see how it goes

 

[Toyaddict]

I found out on my Chinese heater if the temperature sensor on the combustion chamber fails in a way that causes high resistance the fan will not shut off, and it will not fire off. Maybe a person could wire a switch and resistor into that circuit for your purposes.

 

[Kevinm]

Yeah i came across that info aswell. You can accomplish the same thing by shorting out the two wires running to the sensor. On mine i found that it cycles the fan (fan on 90% of the time) and no way to control the speed i don’t think

 

[burleyman]

What Naters said above.

The fan(s) motor shaft protrudes from both ends. The motor drives two fans, one (black) for interior heating. The second fan on the other end (brownish) that you can't see, draws in combustion air, and shoots it out the exhaust pipe. The Amazon link below shows the fans. Notice the chunks removed on the brown fan for balancing. Combustion air would be flowing all the time with no flame.

My 2kw Chinese version has developed a short squeal on cool down after seven years of fairly light use.. A replacement fan assembly is half the cost of a complete heater kit and is rather time consuming. I'd rather replace the entire heater. That would provide lots of spare parts.

Motor noise/squeal is a common complaint for them all on the web.