Any engineers? Furnace exhaust heat. That's a lot of heat!

[Brandon T.]

Originally Posted by vswingfield

I think that you should embrace the water boiling. Get a small steam engine and use that to drive an alternator. Drive the alternator by running the belt off the flywheel, just like the old days.

Use the power generated to charge your batteries.

You could place it outside by the existing vent, eliminating the CO issues.

Lol! That's awesome.

[Brandon T.]

Originally Posted by OTRA15

[ . . . 30 minutes later from another night owl . . . ]



It is all lost heat. Welcome to the world of RV travel -- full of contradictions, inefficiencies, and miracles.

Go to bed and get a good night's sleep . . .



Glad you got the batteries sorted out, Brandon!

Peter

Me too! Seems to be holding well. Not stressing me out anymore.

Originally Posted by mimiandrews

Just remember there's some poisonous CO gas in that furnace exhaust. Any device to capture the lost heat must be prevented from diverting that into the air you breathe.

Co2. Got it.

[Magnet18]

Originally Posted by Foiled Again

My first AS was a 22ft. FB with a SMALL unvented furnace and electric tank heaters. It put out LOTS of heat for its size and propane usage, and the interior space was small enough that the whole place got warm quickly.

There is at least one marine propane stove which has a double layered exhaust pipe that draws in and warms outside air for combustion while the other exhusts the CO, water vapor, etc. Seems to be a little less piggy than a furnace where the pipes have to warm up before the air starts heating.

I'd choose this over a non-vented catalytic heater. Trouble is where? In a 25 Eddie Bauer. Thru the front window? Right over the propane tanks.... kaboom! Anyone?

Different layout, but I replaced a bedroom closet, very pleased

[Magnet18]

Originally Posted by Brandon T.

350°! That's...hot. I'd imagine one could even get that up further by using an insulated funnel to a 1/2 diameter directed at the device.
Exactly what I was thinking whilst hiking or out to have that tied into a simple lithium phone battery bank for use later. A contraption with a thermocoupler would maybe produce .05 volts and over couple days might recharge a battery bank the size of your hand.
A thousand? Twelve under a candle power will get you 12 volts(of course your wasting a ton of Watts using the candles. ) It's a neat back up to a back up if you have a power outage for days and didn't have a generator. Simply put one of these together and using a candle one can sloooowly recharge a phone while making hot chocolate on the other side.
Back to mulling over my options.

Yea but you won't get a useful amount of power

One of these would be way easier than soldering 1000 anything
https://www.digikey.com/product-detail/en/adafruit-industries-llc/1335/1528-2088-ND/5994925?&gclid=CjwKCAiA0uLgBRABEiwAecFnk1DUvqCdV1F j6TGZrzMeBiOUQPXMAczpz95dwo5-uBDetlvqNlcrGhoCx08QAvD_BwE

[Magnet18]

Originally Posted by Brandon T.

Co2. Got it.

CO, NOT CO2, one is an inert gas, one is a poison, big difference

I can't strongly enough discourage doing anything to impede or alter the furnace exhaust, especially venting it under the airstream where it can rise through the floor. Even a snowbank building up against a furnace exhaust vent can cause CO to back up into houses/RVs and has killed people

Any sort of heat exchange experiments need to be careful not to impede the furnace exhaust

[perryg114]

Get one of those propane catalytic wall heaters. More efficient than the furnace.



Perry

[Frey]

Originally Posted by Magnet18

How did you capture the heat and use it to warm the tank, without a pump?
I have a woodstove, and am curious about using it to heat water, but haven't noodled through the best way to do it.
The stove has threaded bosses to accept bolts, so a plate with tubes on it isn't difficult to do, but my concern is water in the tubes boiling

I used a check valve in the tubing on the tank side. Once the water heated, it pushed toward the low pressure side and pulled from the tank causing a syphon effect. The warmer the water, the faster it sucked. It never boiled. I made a copper heat exchanger that fit the rear of the stove. Since the stove and heat exchanger were higher than the tank under the floor, it often circulated the water even after the heat dropped.

[GM Airstream]

actually the most effecent way to heat is with elect... but, if its getting that cold.. what is the price of a gallon of gas vs the propane and use of battery ?

As stated above.. I too read the engineers report about how airstream wanted to improve the effecency of their trailer heating and cooling... so by adding a second AC unit and going to a more expensive radiant heating system.. I guess you could get that elusive 5 or 10% more... but as stated at what cost...

The problem is Airstream is just not insulated that well... and it starts with the hull... Alu conducts heat(cold) quite well... so with it being all alu.. it can transfer the outside temp right through the attached alu bulkheads to the interior alu skin... what about raising or lowering the temp inside... about the same a if your using a tent so some have said...

but... the best part I like is that A/S couldn't get it more effecent... and so instead played with the words... where as full timing was a possibility.. under the old environmental standards... it now is not.. and so they changed from a full time to 3 seasons trailer... of course you know what season they thru under the buss... so by going that way .. THEY DON'T CARE... about your expendature for heating or cooling... after all you bought it... end of story... kinda thing.. once it out the door.. its your problem...

That being said... I did confirm the gents statement above... when he said he used about 30# of propane more... (about 20 bux)... not bad... I know when I was full timing in my earlier AS... we had a 100 lb pig tank that we were hooked up to.. and it lasted about 30 days... but, we also suplemented the heating with the AC heater also... just to circulate the warm air around inside.. and not put a high demand on the heater blower motor... kinda thing.. after all them heater blowers only have DC brushes...(yes you can get a 120 vac motor.. ) and they will only last about 20 years... with full use...

the adventure contenues...

[Brandon T.]

Originally Posted by perryg114

Get one of those propane catalytic wall heaters. More efficient than the furnace.



Perry

Almost on the same wavelength. I was thinking along the lines of a flue recovery system. Such as this one. Not sure if this exact one would be compatible but this is where my idea was headed. Would compliment any winter heating furnace while at the same time being able to take advantage of preheating the cool water and taking not as long for it to warm up for showers etc. Possibly save on propane cost.

http://www.superhomes.org.uk/resourc...overy-devices/

[Brandon T.]

Originally Posted by Magnet18

Different layout, but I replaced a bedroom closet, very pleased

That is awesome.

[perryg114]

Your going to save much more if you put 2 inches of insulation on the inside walls. As others have said, the Airstream is like trying to heat a metal shed with no insulation. Not quite that bad but not great. There are also ways to help with thermal control by painting the roof black in the winter and white in the summer. You could put a solar hot water heater on the roof and use that to heat. If you are in the UK where there is no sun it might not be an option.



Perry

[Magnet18]

I have found that my wall insulation is in pretty good shape, i lose way way more heat through unsealed cracks and drafty windows.
Plastic and aluminum tape over the bedroom windows raised the temperature in the back of the bedroom about 10 degrees
The floor is totally uninsulated, nothing but plywood, and as a result is usually 50-60 degrees. I have 2" of insulation to put there, haven't gotten around to it

[Brandon T.]

Originally Posted by Magnet18

I have found that my wall insulation is in pretty good shape, i lose way way more heat through unsealed cracks and drafty windows.
Plastic and aluminum tape over the bedroom windows raised the temperature in the back of the bedroom about 10 degrees
The floor is totally uninsulated, nothing but plywood, and as a result is usually 50-60 degrees. I have 2" of insulation to put there, haven't gotten around to it

That's....a surprise. For this kinda money one would think they'd go all out. I was wondering why it was so dang cold there. I bought some fur slippers for that reason. Wow. Ok, I know my next next project.
Aluminum heat transfer plates coming up next. Cool this could stick onto the underside via heavy duty industrial Velcro. That stuff is some serious stick. Target specifically where to put the plates and it should help with the cold.
Three seasons RV....grrr

[OTRA15]

Airstreams have never really been billed as suitable for full-timing in winters IMO.

"Airstream three seasons" search results here FYI:

https://www.google.com/search?q=airs...com&gws_rd=ssl

"CO winter full time" -- https://www.google.com/search?q=CO+w...=airforums.com

Some of the threads/posts contain links for better winter camping trailers.

https://www.google.com/search?q=wint...=airforums.com
http://www.airforums.com/forums/f48/...am-170763.html

Good luck,

Peter

PS -- Good general guidance re: Arctic Packages etc.:

https://camperreport.com/best-cold-w...-extreme-cold/

Airstream is not on the "top ten" list.

[Magnet18]

As-sold, airstreams aren't 4 season

Some minor mods and they do just fine though

[vintageracer]

Wear more sweaters and sweat shirts to increase body heat in the trailer.

No exhaust gas issues either!

[JCWDCW]

Some years ago we had our '89 Excella re-coated and while in Mississippi on the way south the door didn't latch and blew open in the night. When I heard the furnace running excessively long I got up to inspect and found the door had latched against the trailer with the furnace vent blowing directly on the door!. I was sure the door was cooked and would require some attention....nothing....the re-coat was fine. Despite the apparent temperature, it is fairly normal. As a comparison, the exhaust temperature of a standard B Vent home gas water heater is way higher. I suspect the exhaust from the water heater is also higher than the RV furnace.
JCW

[Native143]

So I have a 20’. On another subject though, How are refrigerators vented? I occasionally smell what seems like exhaust coming from the refrigerator when I have my AS door open. Do I have a leak or is this normal?

[bartzstream2]

Originally Posted by OTRA15

[ . . . 30 minutes later from another night owl . . . ]



It is all lost heat. Welcome to the world of RV travel -- full of contradictions, inefficiencies, and miracles.

Go to bed and get a good night's sleep . . .



Glad you got the batteries sorted out, Brandon!

Peter

I would just like to add that the furnace fan (which supplies both combustion air and also circulates the heated air out of the furnace and into the trailer cuts off somewhat prematurely, since there is still plenty of heat yet to be extracted from the furnace for a period after the actual burn has ceased. I wonder why. I think the electronics set the fan limits incorrectly, at least as far as maximizing the amount of heat directed to the trailer interior is concerned. Perhaps there are other considerations of which I am unaware being purely a layman, but also a problem solver. Comments anyone?

[CruizinDux]

Originally Posted by Native143

So I have a 20’. On another subject though, How are refrigerators vented? I occasionally smell what seems like exhaust coming from the refrigerator when I have my AS door open. Do I have a leak or is this normal?

native 143, I'll send you a PM so as not to get this thread too off track.
bob