New outside vented stove design

[planet-beaver]

Bob just posted a video about heating the van. I use a stove just like him cause I think the Buddy heaters are pointless. BTU per LB of propane is the same no matter how you burn it. One major problem for me is always mousture. Everything gets wet and damp. Not a big problem in the desert but out east, it will drive you insane. Plus I always smell the propane fumes. Can't be good long therm.

Anyways, I worked as an engineer designing cooling and heating systems for 24 years and I think having a vented heater for small spaces would be awesome. I just designed one and want to see what you guys think.

The heater is a solid aluminum plate 12" long by 8" wide with two sqaure tubes, one as a burning chamber, the second as a manifold for fumes. The heater will be at 45 degree angle so that the burned gasses will travel up and out. It will be vary efficiant. 97% of heat is tranffer to the heater unlike most furnesses that have simple baffle. The gasses have to slowly travel up in small channels tranffering heat to the aluminum plate. Because the plate is at 45 degree, the surrounding air will travel through the holes grabbing the heat. There will be mount holes to add $51 eight inch fan (12v). One can place their feet on the heater to warm them up (my biggest problem in winter) because it is at 45 degrees and it is solid plate. Everything would be machined and bolted making this thing last forever. Other than propane gas valve and fan, nothing else to brake. It would require two holes to be drilled in the van for intake and exhust pipe (standard 1" NPT fittings so you can run it however you want it). The valve will controll how much heat you want (basicaly having 9 tiny pilot flames) and can be left on all night long supplying steady dry, fumeless heat. 20lb tank should last 80-100 hours.

I looked at the heater cores and radiotors for this design but they are too weak for travelers. One bump and they get demaged. All small heaters on the market are ventless and the vented once are huge and cost a fortune.

So what do you guys think? Good,bad idea? Any conerns? I can have it priced to see how much they would cost if there is intrest for it. Not trying to make money here. You would buy it directly from a machine shop.

 

[planet-beaver]

Couple more images

 

[user 13531]

Fan-tastic.... Add a "ODS" sensor and you're good to go!

 

[Minivanmotoman]

Great job. And it doesn't appear to be rocket science. Different fuel. Lol. Couldn't something like this be made from off the shelf parts or minimal fabrication?

 

[user 13531]

Wall mounted gravity flow propane heater for vans and rv's.... He's already filing for a patent

 

[planet-beaver]

This is nothing new. There are many vented heaters on the market but they need electricity, are huge, designed to heat large space and cost arm & leg.

 

[regis101]

I like the concept.
The heat exchanger idea is ingenious. It's almost like an air to air turbo intercooler.
How do plan to keep the burned gases sealed with the two piece exchanger design.
As long as you calculated the amount of BTU's and/or propane flow per burner port vs channel volume vs length of exchanger , all should be well.
Keep going. The RV world needs a better heater .

 

[skyl4rk]

Some thoughts:

Make it so that it can be mounted vertically so it doesn't take up much room.
Or flat on the floor, strong enough to walk on.
It should be able to operate at low levels when you don't need a lot of heat.
Can it be run overnight safely?
Can it be run without a fan?
Is it too hot to touch without burning yourself?

 

[Weight]

There is a reason to use steel or iron for contact with gas flame. Aluminum can ignite.

 

[tx2sturgis]

It's a basic design that could work but...

It definitely needs a safety screen or grill around the front and probably some insulating standoffs for the fan frame. 

And it needs a real safety valve with a thermocouple. 

It reminds me of a simple heat exchanger...just have to use the right materials and balance the sizes of the different parts to match the heat levels.

Still, you may be on to something here!

 

[planet-beaver]

There is a reason to use steel or iron for contact with gas flame. Aluminum can ignite.

Most cookware is aluminum. You need extreame temperature and air to ignite Aluminum.

 

[planet-beaver]

Some thoughts:

Make it so that it can be mounted vertically so it doesn't take up much room.
Or flat on the floor, strong enough to walk on.
It should be able to operate at low levels when you don't need a lot of heat.
Can it be run overnight safely?
Can it be run without a fan?
Is it too hot to touch without burning yourself?

It has to be at 45 degree to work without a fan. Not everyone has power storage to run fan all night. If you place it verticaly, you need a fan to blow thru holes. If you lay it down, the gasses will not rise and you will need long vertical exhust pipe to create suction

 

[planet-beaver]

It's a basic design that could work but...

It definitely needs a safety screen or grill around the front and probably some insulating standoffs for the fan frame. 

And it needs a real safety valve with a thermocouple. 

It reminds me of a simple heat exchanger...just have to use the right materials and balance the sizes of the different parts to match the heat levels.

Still, you may be on to something here!

The front grill would require more manufacturing steps and safety switches would complicate everything and now, it neads power to run it.

Im trying to keep this design simple and available to anyone. I will have couple shops quote it but i will upload all CAD drawings here so you can try to build it elsewhere. 

Milling machine will be needed. Does not have to be CNC as i keep everything in straight lines for easy of machining.

 

[tx2sturgis]

The front grill would require more manufacturing steps and safety switches would complicate everything and now, it neads power to run it.

Yep but off the shelf hardware cloth (metal mesh) would be super cheap and easy. And the fan is using DC power, so you would already have DC in, and the safety valve and thermocouple do not need external power, thermocouples are heat powered.

For high pressure propane, you need a regulator, but that can be at the tank, rather than at the heater.

Then also you would probably combine the safety valve with the tube and gas orifice, gotta have that. And maybe a way to regulate the air intake, for different altitudes. 

These are a few things it would really need to have...just sayin...

 

[skyl4rk]

I prefer simple and no electricity needed. But I don't have much floor space. Could this be mounted under a desk or bed? Or movable?

 

[MrNoodly]

Is this device "smart" enough to vent out only the by-products of combustion and not the heat?

 

[skyl4rk]

A couple more questions: Does this use regulated propane or high pressure propane? Is it one setting only, or can it be adjusted - high, medium, low?

 

[MrNoodly]

The flames can heat air directly, but you're using the flames to heat the metal and the metal to heat the air. That seems less efficient.

 

[tx2sturgis]

On all vented, gas fired heaters, there is always a metal barrier between the combustion process and the heated air on the other side.

 

[John61CT]

> Most cookware is aluminum. You need extreme temperature and air to ignite Aluminum.

I've many times let an aluminum pot boil dry and returned to a molten puddle.