Propane heat for T@G

Trailpixie

Has anyone considered one of these propane heaters for their T@G. It seems like it could be mounted beneath the T@G as indicated in the information below. You could also mount it on the tongue platform...or even possibly in the space under the sink(with the right venting).

http://www.propexheatsource.com/heaters/hs2211-furnace/

Discuss... :-)

WilliamA

Very interesting. I have lived in Europe off and on for many years (more than 12) and have seen all manner of tiny Caravans and Vans. They are ubiquitous over there and are as common as fleas. In the south of France, you can see them parked all over the place at night in parking lots, vineyards, church parking lots etc. The takeaway for me is that "those guys" have many more options for this kind of RV accessory than here where RV's need to be at least 500 feet long and have no less than 6 A/C units. (If it is as big as the space shuttle, weighs as much and gets the same mileage, it might BE the space shuttle!)

This heater is an example of that sort of technology, as are the vaunted (occasionally cursed) ALDE units that come in the T@B. I had mulled over the propane option for a long time before I installed my electric furnace. For me, the stick across the trail was unit cost. These things tend to be pricey. In addition, they tend to be way too big (thermal output) for the space needs of tiny trailers. Too big means inefficient. Let's break down the numbers for this unit:

PROPEX HS2211 FURNACE TECHNICAL SPECIFICATIONS
HEIGHT 9.06″ (230mm)
WIDTH 6.18″ (157mm)
LENGTH 16.93″ (430mm)
WEIGHT 16.98 lbs (7.7kg)
HEAT INPUT 6824 BTU (2.0 kW)
VOLTAGE 12V DC
CURRENT CONSUMPTION 1.7 A
FUEL Propane or Butane gas

Size and weight are well within the target of teardrop trailers. The PDF that accompanies this brochure give the voltage input range at 10-15V dc. That's fine. Nominal current is 1.7A. Also fine. It will work on Propane (American fuel of choice) or butane (European fuel of choice).

The sticky wicket for me is the heat input rating (how much heat you'll be getting all the time the unit is running), which is stated at 2kW! I've done many tests of ambient heat rise and hold and have come up with my own personal perfect number of .8 kW for a T@G. The heat output of this furnace is nearly 2 1/2 times that. It'll heat a trailer very well, but will be horribly inefficient. The installation PDF states that the furnace will require 150 gm/h of propane at 37 mb. That translates to 6 hours of burn time per kilogram of fuel. At 2.2 lbs per kilo, a 5lb cylinder of propane (4.2-4.4lb full) will run out in 12 or so hours. A 20lb propane cylinder would net about (I said "about") 3-4 "heating days" (that's total amount of time the furnace can run continuously), not including the amount of fuel you'd use for cooking.
My own experiments in heating have shown me that too hot is almost as bad as too cold. I'll leave that discussion for later and just present the numbers here.

According to the installation instructions, this heater should be fairly straightforward to install. I'd have to give it some thought and do some figuring, but I can see a few places that it could be mounted without too much trouble. One big caveat of the mounting is (as specified in the mounting instructions) that it must be shielded if mounted outside. That means it needs to be mounted in a metal box of some sort. It's not hard to fabricate a box out of ductwork but that has to be considered in. Sounds like you can't simply hang the thing off the bottom from a couple of pieces of plumbers strap.

The last potential problem is availability. According to the paperwork, it's "Countries of Destination" list doesn't include the USA. That probably means it's not certified (tested) for use here. Whether that means it's not available here I don't know. As to the certification, that wouldn't stop me from using it if I satisfied myself as to the safety factors.

I'd consider this sort of heat system (and have before) if it fell within the "bang for the buck" window I use for my trailer. If you do lots of off-grid boondocking in cold weather, then this is a good option. Installation will be a significant factor (if I were installing it myself, I'd use 25% of the cost of the unit as a number for installation.
If I were having it installed, I'd double the cost of the unit for installation) when figuring the total cost, as will be propane refills. Again, it just depends upon how often you'll be using it.

Considerations must also be made for maintenance. Are parts readily available? Can I do the maintenance (both repair and periodic) myself or do I need to outsource it?

Overall, it's worth much consideration and a bit of research. I consider some sort of reliable heat to be an absolute "must-have". There are many factors that I have preached to in other threads. I'd love to hear about any other research or experiences others have done/had on the topic.

WilliamA

Trailpixie

There is a US site with some distributors. http://www.propexheatsource.com/about/

I thought of installing it in the microwave location.

Hopefully the thermostat would cycle the unit on and off to keep the heat from being too hot. Where to put the outlet and return is a different question.

I don't think you would want a 20 pound propane tank. A 5 gallon would be lighter and more compact. Could also be used to fuel the stove.

As for price....that is a good question.

Michigan_Mike

I've seen that unit before but never have seen anyone install it inside a trailer. I thought about it briefly when I had my Silver Shadow and figured that something like that was a viable option with the use of propane. You'd have to be very careful with ventilation and air intake since these trailers are so small.

Trailpixie

@Michigan_Mike , the propane burning part of a heater like this doesn't vent into the living space. There is a heat exchanger that keeps the propane part completely isolated from the venting part.

Brent

Propex is the way