Old skool gravity propane heater

[oltrunt]

I'm trying to use tapatalk again--hope it works!  You May have to enlarge the print in order to read it.  Jack

Sent from my LG-M255 using Tapatalk

[bevans6]

What makes it a gravity heater?

Brian

[oltrunt]

Brian, I asked the same question and after a bit of internet sleuthing, I'm still scratching my head.

I just went back to the net and found an explanation presented with great gravity by some long winded scientist.  Apparently materials who's molecules are tightly packed together have greater mass (hence weight) than materials who's molecules are loosely, less densely packed together.  Dr. science went on to explain that as air is heated it's molecules move  about more rapidly and begin to spread out.  This leads to fewer hot air molecules per volume than would be the case with cold air of the same volume.  The relationship between mass, volume and gravity somehow equates to weight and since hot air weighs less than cold air, hot air rises and cold air flows down to replace it--the basis for the name "gravity heater"

Bet you're sorry you asked--I know I am   Jack

[dtcerrato]

That's a very nice story Jack! Count me in when it comes to maintaining a vintage excellent piece of equipment. Lots of stuff that was salvaged out of our class C S&S after we totalled it on the grapevine went into our 4104 conversion. The "Fireball" S&S was a 1973 so it was going into a 53 bus and was like new stuff. One appliance in the bus to this day (as many appliances have been upgraded over the years) is an Empire radiant heater with an optional 12 volt blower fan on it. No electric other that that, light with a match, pilot light from there. It's only 11,000 btu propane. 5000 of that can be forced into the insulated holding tank compartment with the optional fan. Some years back we finally found a replacement gas control valve for it and was able to keep it in service. It is an ace in the hole especially if the batteries are dead. It has bailed us out a few times over the years and is externally vented for intake & exhaust, It is a backup to a modern Atwood 35,000 btu furnace and a memory awakener everytime we use it. I'm with you Jack...

[bevans6]

There are several new "gravity propane heaters" on the market, or so a cursory glance at Mr. Google shows.  I would personally call them convection heaters, gravity has nothing (directly) to do with it.  Simple, use no electricity (except some have a spark igniter), nice idea.  If the heatbox passes a corrosion/crack inspection, there is about nothing else to go wrong.

[sledhead]

this looks like a nice unit

http://propanedepot.ca/products/direct-vent-wall-furnaces/martin-mdv20vp-direct-vent-wall-heater/

dave

[oltrunt]

Wow!  That's nice.  If I was just starting my build I'd be all over that one.  Jack

[oltrunt]

double entry for some reason?  Jack

[Oonrahnjay]

this looks like a nice unit

http://propanedepot.ca/products/direct-vent-wall-furnaces/martin-mdv20vp-direct-vent-wall-heater/

dave 

     So, OK, there, eh!  Is it, like, for sale in the US, there, eh?  (Approved or recommended for vehicle use?)

     Also, anybody have any idea how you'd vent the "direct venting" in a vehicle installation?  How about the window?  There is a "VP" model with the window to look at the warm part and a "P" model without the window but same BTU rating -- would windowless be safer in a vehicle? 

     Nice.  Amazon in the US lists it as approved for US,   $1265 CDN.  "Does not ship to your location."

[sledhead]

the us model

https://www.amazon.com/Direct-Propane-Heater-built-thermostat/dp/B071ZTDX14?th=1 


way less $$$ for you guys

dave

[oltrunt]

I nearly choked on my gin when I saw the price!!!  $699--REALLY?  I'm not affluent enough to even consider that item.   Jack