Catalytic heaters, how big 8.5 x 24" cargo trailer

[Sevo]

I am converting a 8.5 x 24' trailer and was looking at one of the catalytic heaters. I see they make heaters that go from 1600-8000 BTU's. How many BTU's do you think I would need to heat a trailer this size?

Thanks for the help guys

Chris

[8ball_99]

Uhh your going to want the 8000 atleast... It depends a lot on what temps your camping in, your insulation, and how quick you need to heat the trailer up.. I have a 7x24 plus 2' V.. I have a 19,000 Btu furnace.. It will take my furnace about an hour or so to heat the trailer up from mid 20s to around 68-70. I can pretty much keep it as hot as a want after that. While I was building the trailer we stayed in it a couple of times before the furnace was fully installed.. With just a Mr heater heater buddy, Which on high is 9,000 BTUs it would take a while to get the trailer warm. I would not go any smaller then around that size in less you just won't ever need to warm the trailer up very fast. Once everything on the inside is warmed up keeping it warm isn't a huge deal. But that first little while when all the surfaces are cold the trailer will just swallow heat.. BTW mine is fully insulated,, even the floor. HTH

[Glenlivet]

I'd say def the 8000. I have the 1600-3000 in my 6 x 10 and it's just about right, even a tad small.

Mount it so it aims at where you sleep or where you hang out. It's better at direct radiant heat than at heating the air and the air warming you.

[Sevo]

Thanks guys for the replies.

After some research and after looking at 8_balls conversion I don't think the catalytic heater will be enough. I think I will go with the furnace. I feel this will be our best option to heat the entire trailer.

If you guys know of a good one on sale please let me know

thanks for the help

Chris

[8ball_99]

Np, And don't get me wrong a 8000btu would probably work. Just would take a long time. If you can stomach a RV furnace its really the way to go.. I got Very lucky on mine.. On ebay I bought a suburban 19k ducted furnace brand new in the box for around 320ish.. At the time it was atleast 150 cheaper then I had seen anywhere else.. Might be worth keeping an eye on there. Just really look hard at anything used. Some times you get lucky and people just upgrade to larger units quickly.. I'd avoid older units or anything missing parts.. You better off just buying new cause you can easily spend a couple hundred bucks getting a bad one working..

Thanks guys for the replies.

After some research and after looking at 8_balls conversion I don't think the catalytic heater will be enough. I think I will go with the furnace. I feel this will be our best option to heat the entire trailer.

If you guys know of a good one on sale please let me know

thanks for the help

Chris

[Sevo]

Np, And don't get me wrong a 8000btu would probably work. Just would take a long time. If you can stomach a RV furnace its really the way to go.. I got Very lucky on mine.. On ebay I bought a suburban 19k ducted furnace brand new in the box for around 320ish.. At the time it was atleast 150 cheaper then I had seen anywhere else.. Might be worth keeping an eye on there. Just really look hard at anything used. Some times you get lucky and people just upgrade to larger units quickly.. I'd avoid older units or anything missing parts.. You better off just buying new cause you can easily spend a couple hundred bucks getting a bad one working..

Thanks guys for the replies.

After some research and after looking at 8_balls conversion I don't think the catalytic heater will be enough. I think I will go with the furnace. I feel this will be our best option to heat the entire trailer.

If you guys know of a good one on sale please let me know

thanks for the help

Chris

Great advice! I wont rush on that for sure, especially with summer coming around the corner. I was thinking 19,000 BTU or bigger. I really think it will be a lot more efficient to heat that big space than a catalytic.

I will need to plumb the propane in preparation to getting the furnace and I just ordered my stove top. . Do you guys have a quick and dirty site on how to do the plumbing for LP. I have never done LP lines before.

8-ball, where did you run yours?

thanks for the help
Chris

[8ball_99]

I used copper all the way on mine.. Most travel trailers have black iron under the trailer and copper inside. Reason is the black iron is very tuff so rocks flying up, ect won't hurt it. If I would have used black iron it would have added atleast 3 connections to my line. I also would have had to run the iron down low because of the way the framing is on my trailer. With the copper I was able to drill out the joist and run the line through them right up under the floor. So the line is pretty well protected. I also didn't have to run mine very far since all my stuff is in the front of the trailer. Right where the line comes in the trailer I installed a shut off valve. The idea is if you smell gas or have a problem with an appliance you can shut the gas off quickly vs rushing outside and turning the bottle off. (btw you should still turn the bottle outside off) The idea thing would be to have a main shut off first and also have shut offs for each appliance.. Shut offs need to be in an easy to access place. Problem is a bunch of Valves and pipe in easy to access space means you loose a bunch of easy to access cabinet space. lol. So I just have the one main shut off inside.
Copper isn't that hard just tank your time and don't kink the line when running it. All you need is a flaring tool, cutter and the various fittings to connect everything.
Here is a picture showing the regulator and the copper line going down to the frame of the trailer

Here is a picture showing the valve and the connections inside.


I don't have any pictures showing the line under the trailer.. you don't really thing to take pictures of that stuff while your doing it. Most of the pictures I did take are just with my phone, A buddy asks you what your doing you send him a pic lol

[Engineer Guy]

Last time I ran the numbers, the usual 1,500 Watt Electric Heater sold everywhere = 5,200 BTUs each. They draw about 13 Amps at 115 VAC. With adequate temporary Electrical supply off of, say, 2 or 3 separate AC Breakers, you could run/borrow several such Heaters and run actual Tests using 10,400 BTUs [2 Heaters run simultaneously] or 15,600 BTUs [3 Heaters run simultaneously] and see, in general, what BTU level provides the results you want.

If it hasn't jumped off a Furnace Spec Plate at you, note that there are Input BTUs and Output [actual delivered] BTUs on Furnaces since they're less than 100% efficient. You would want to concentrate, after the Electrical Heater Test, on finding a Furnace that has the Output BTUs you want; not the Input BTUs.

Other than the fact that Electrical Heater 'heat' might stratify up to the CT Ceiling, since warm Air rises, and a Furnace Fan pushes Air around and equalizes it, this proposed Test should get you in the BTU ball park req'd without guessing and wasting money. The point about stratification is that Air moved around 'feels' more comfortable. This means that fewer BTUs might provide equivalent Human comfort IF that Air is moved around by a Furnace.

I can't stand the Furnace noise in my '83, 31' 'Avion' Trailer. However, the smaller, non-ducted Furnace in my '89 ~15' 'Play-Mor' Trailer is significantly quieter.

Catalytics do produce the byproduct of Water/Humidity. Some folks don't mind that; other do.

[Sevo]

8_ball, great reply . I really like the way you have done your conversion. You really have put a lot of thought into the little things. I appreciate you sharing those with us. I will do just the same with mine.

Engineer: Thank you as well. That is a great idea of how to get the BTU's needed. I would have never thought of that. I will give it a shot and see what I can come up with.

Thanks again for all of the input guys. I really appreciate the help

Chris

[8ball_99]

NP at all, Glad to help.

Engineer guy is right on the Furnace input VS output.. They are rated on the input and some of the heat does go to the outside. I never had much luck finding the true output BTU rating when I was picking a furnace. I went with the 19k one because it was the highest output in that size cabinet. I also looked around at the size furnace that comes in commercial travel trailers of around the same size. You don't want to go to large or you will burn up. These things have a 5 min cool down. Meaning once its running and the set temp is reached the furnace still circulates air for 5 mins to cool it down. Since its still very hot it will keep blowing hot/warm air during this cool down. Couple that with these things are either off or on. There is no low, med, hot. Its just hot and off.. Stick a 40,000BTU furnace in a 24 footer and you will probably hate it inless its VERY cold outside.