Decisions, Decisions

So almost three years out from the initial hatching of the idea I drove home a new Toyota Tacoma. I am looking at the Bobcat shell and a few things.

I camp a lot in the winter so for me the water system is a waste of money and space but I'd like a real for true propane cabinet. I am thinking about the stove and some space for pots and pans.Maybe the icebox? I'll build my own sofa/bench because I want to be able to slide my skis beneath it or I may put the tracks on top. 

And I think I would rather have a radiant heater (I've been happily using a Buddy, am also interested in the Wave) than the forced air with it's noise, voracious use of fuel and need for an additional battery. 

In the winter I typically run The Buddy heater for a few hours in the evening and a few hours in the morning. I will sleep in a down bag and a synthetic comforter on a bench in the lower space and keep the top down if the temperature will be in the low teens or if there is a call for substantial snow overnight (I have difficulty cleaning enough snow off the roof for it to not be a frightening experience to lower) I don't mind cold but I have limits. If it will be in the single digits I get a room. My regular haunts are Eastern Callifornia from Tahoe to Mammoth. I remove and store the heater in the summer (usually earlier than I should)

And I have dog(s) (one just passed this summer - have one, will get another) Golden Retriever kind of guys. Fluffy tails and open flame. With that in mind forced air sounds great. But I don't camp near electrical outlets. 

How many hours of blower would I get off of the battery? (how long would I have to run the blower?) How quickly would  the battery re-charge? (I often don't drive many miles from campsite to ski trail) I know the answers will likely include something along the lines of "it depends" but what have other people considered? 

And this truck and the camper will be my only vehicle, I am going to leave the camper on so I need to retain space in it to haul trash cans and Home Depot stuff. And I'd like to keep the weight of the camper down. What does that extra battery weigh? The heater itself? 

Any advice is welcome. 

Edited by teledork, 29 December 2019 - 12:00 AM.

Hey, welcome back!  Congrats on the truck.  I believe you will be pleased with ATC, and they can certainly build it to fit your needs.  
 

I do recommend a furnace for heat, as it significantly helps control condensation, as well as a Fantastic fan and second vent.  Talk to Marty about more than one battery to extend your run time, and how to maximize your interior room..  The extra weight and space is dependent on the size of the battery, but I’m thinking 100 - 120 pounds.  Consider a good sized solar panel to help keep the battery(ies) charged.   
 

The Ski3pins have both a furnace and catalytic heater, so they could weigh in with their experience.  You might think about a portable Wave 3 to keep it out of reach of puppy dog tails.

Ask ATC about a wider door to accommodate trash cans and other bulky items.

I think you’re wise to minimize interior accommodations.  I overbuilt my Bobcat, then found it was very cramped with an 80 pointing dog, my gear and me.

If you want to chat, send me a PM, and I’ll detail how my Bobcat was built, and what I will do different on the next camper.  BTW, the next one will be another ATC.

Steve
 

Yup. Condensation. And I have poured over the 3 Pins's build. My cabinetry is - ahhh - rougher. 

Thank you for the conversation Mr Sagebrush. Just like camping I find the generosity of the people on this forum to be a wonderful balm for a sore spirit. 

How many hours of blower would I get off of the battery? (how long would I have to run the blower?) How quickly would  the battery re-charge? (I often don't drive many miles from campsite to ski trail) I know the answers will likely include something along the lines of "it depends" but what have other people considered?

There's good reason for "it depends" as there are can be many variables but here's my .02 ....

We used to do a bit of winter camper back in the day and my rule of thumb was the single battery would last ~ 2 days. So, a weekend without charging. This would be say, in 25 to 10 F weather running the furnace a few hrs each evening and morning.

Doesn't seem like much, eh ?

If I do a calculation using batt and furnace specs and a few of my own values I can come up with ~15 hrs of run time. Note, I'm thinking during the hours we are heating, the blower cycles on ~2/3rds of the time. So that ~15 hrs of blower run time could be ~22 hrs of "heating time". Say 4 days of use. That's double my recollection but the calculation is max/best case and we were also using the batt for lighting and perhaps other things.

Also note, ours is a 16K BTU furnace. The 12K BTU version then was rated at ~25% less current draw which could affect total run time capacity. And if you could slow down the heat loss thru the camper envelop (perhaps with an arctic pack ?) the cycling on time might be reduced.

From those days I decided - and suggest - for future winter camping we'd have 2 batteries and plenty of LPG. Now, I think I'd add having  a second method of heating - just in case. And I would oversize capacity - heating is just too important.

Further considerations:

-Typically battery capacity declines with battery age and, typically a battery will deliver less capacity as battery temperature is lowered. Keep the batteries warm if possible.

-A furnace is ideal for quickly heating up the interior. Great when you are coming in from the cold and wet.

-Forced air can speed up drying of wet clothing.

-Fully charging can take a long time !

Edited by klahanie, 29 December 2019 - 01:37 AM.

So almost three years out from the initial hatching of the idea I drove home a new Toyota Tacoma. I am looking at the Bobcat shell and a few things.

 

I camp a lot in the winter so for me the water system is a waste of money and space but I'd like a real for true propane cabinet. I am thinking about the stove and some space for pots and pans.Maybe the icebox? I'll build my own sofa/bench because I want to be able to slide my skis beneath it or I may put the tracks on top. 

 

And I think I would rather have a radiant heater (I've been happily using a Buddy, am also interested in the Wave) than the forced air with it's noise, voracious use of fuel and need for an additional battery. 

 

In the winter I typically run The Buddy heater for a few hours in the evening and a few hours in the morning. I will sleep in a down bag and a synthetic comforter on a bench in the lower space and keep the top down if the temperature will be in the low teens or if there is a call for substantial snow overnight (I have difficulty cleaning enough snow off the roof for it to not be a frightening experience to lower) I don't mind cold but I have limits. If it will be in the single digits I get a room. My regular haunts are Eastern Callifornia from Tahoe to Mammoth. I remove and store the heater in the summer (usually earlier than I should)

 

And I have dog(s) (one just passed this summer - have one, will get another) Golden Retriever kind of guys. Fluffy tails and open flame. With that in mind forced air sounds great. But I don't camp near electrical outlets. 

 

How many hours of blower would I get off of the battery? (how long would I have to run the blower?) How quickly would  the battery re-charge? (I often don't drive many miles from campsite to ski trail) I know the answers will likely include something along the lines of "it depends" but what have other people considered? 

 

And this truck and the camper will be my only vehicle, I am going to leave the camper on so I need to retain space in it to haul trash cans and Home Depot stuff. And I'd like to keep the weight of the camper down. What does that extra battery weigh? The heater itself? 

 

Any advice is welcome. 

I have a Panther shell with 2 burner stove. I added a Propex furnace below the propane compartment. I gave Marty the exhaust vent for the Propex and he installed it as part of the build. I had a Wave in my previous Hawk and for the most part was satisfied with it but I really like the Propex. I also had a bench seat built under the front window to house my 100ah battery (68 lbs) plus storage for all of our cooking supplies and bedding. My Truckfridge sits next to the stove/propane cabinet and for water I have a 5 gal Scepter water can that sits outside on the AT can holder I spec'd in with the build. I realize the Panther is larger than the Bobcat but so far I'm quite satisfied with the minimal amount of storage space that we have. On all of ours trips this year the only thing we've thrown in the camper is my wife's dufffel bag and Little Giant step stool. Have fun planning your build!!

I would think, things being equal, a higher BTU furnace might use the same battery power as a lower. Maybe less if the air comes out hotter. Theoretically it would run for a shorter time until the thermostat kicks the heater back on again. but... this is all theory!

The furnace is not a voracious user of propane. Battery power yes, sort of. You need a good deep cycle battery. Maybe two. Are you considering solar? Don't forget proper ventilation to keep the condensation down. I have a wave3 for backup heat. Its definitely not as good as the furnace. Radiant heat is great if you're sitting in front of it. I've found myself freezing while the dog is roasting. Plus the added moisture. Even if you go with a buddy or wave I'd want to run the furnace in the morning to dry things out. As for water, if you don't see showering a plus and your trips are short, portable water should be fine. 

I would think, things being equal, a higher BTU furnace might use the same battery power as a lower. Maybe less if the air comes out hotter. Theoretically it would run for a shorter time until the thermostat kicks the heater back on again. but... this is all theory!

Possibly, I don't really know...

Lesser and longer lasting heat output, the direct result of better insulation than found in my camper, would be my preference. If I was ordering custom from ATC this is what I would pursue.

I'm thinking the spec I used in my calc is simply a function of motor wattage, the mfr quoting blower running constantly. The same physical motor may be used in multiple models with differing heat outputs. And multiple models may have the same heat output but be equipped with different motors (thinking of the legendary, low amp 12K Dometic discussed on here before).

Another possible consideration is the gas efficiency of the furnace unit - the "voracious use of fuel", per the OP. I think a Buddy radiant is rated at ~95; a Propex, well mentioned above, is rated at ~90%;  a Truma VarioHeat ~85; and an old school, crappy RV type like mine ~77.

Thanks all!

I was always planning on the cold weather liner. And a Wave heater. And a solar panel.