M1088 camper conversion

ckouba

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Starting to poke around the internet for water heater stuff and found this:


This fits the bill for the two coil water tank, one loop with the engine coolant being circulated and the other fed by an Espar or other hydronic heater. This also has a 12V electric element which I've also seen controllers use as surplus solar loads if the batteries reach full charge and there's still sun shining on them. A unit like this is appealing.

Still thinking about how it (the Espar) might be plumbed to be able to pre-heat the motor if desired, but that should be possible. It would likely require a handful of valves to divert flows but shouldn't be too complicated. I would prefer to keep them separated as to not put too much of an additional load on the engine's coolant pump and I want to make sure there's a sufficient bypass that the Espar's pump isn't going to burn out pushing against a closed thermostat. It's all been done before so I am certain it's possible, but I want to make sure I'm not introducing extraneous issues.
 

NavyNuc84

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Not really... I've honestly got nothing concrete on paper yet, but no better time to start talking about it.

My experience with this comes from working on our boats where we've had hot water heaters with engine coolant loops built in to heat the water in the tank while the engine is running. None of this is researched for compatibility issues, but conceptually I want to have both a diesel water heater and a marine type of water heater (by "marine" I simply mean one with motor coolant loops). These would both be housed in the habitat and I am presently inclined to connect it to the truck system near the expansion tank.

For the sake of this conversation, let's call the tank with an engine coolant loop through it a "tank heater", i.e., a static volume of water in a tank which is heated by the passage of warmer fluid (in this case, motor coolant) being pumped through loops of pipe inside the tank. We'll call the D6L and the others like it a "water heater", as they heating the water directly.

There is a feed into the motor's expansion tank which, if analogous to gas motors I've worked on, should be the input to the tank, and the tap from the bottom should be going back to the motor. What I am thinking of doing is splicing into the line feeding the expansion tank and sending the motor's coolant through the "tank heater" and then returning the motor coolant to feed the expansion tank. This would heat the volume of water in the tank heater to motor coolant temp and get me hot water while underway.

That part feels pretty straightforward. I would make sure the expansion tank remains the highest point of the cooling system and still have to check for any other compatibility issues, but I think it's a pretty solid plan. Until someone here points out the obvious thing I missed...

From here on out, I am improvising for the sake of discussion.

There are two ways that incorporating diesel water heat could be done fairly easily. The simplest is a diesel water heater like the "tank heater" I described above except with the water being heated by combustion of diesel fuel instead of passage of engine coolant through the tank. A selector valve would need to be used to avoid pulling water from the motor side tank if it's already cold and I know we'll only use the diesel side tank. What's the down side? I don't think they exist.

The other fairly easy way is a tank heater which has a second set of loops through it. In a tank heater like this, I could use one set of loops for engine coolant (spliced in as described above) and the other one for the fluid heated by a "water heater" like the Espar. What's the down side? This system would require a bit more plumbing, using the water heater as a hydronic heater and pumping the hydronic fluid through the second set of loops, but the side benefit is we could also use the hydronic fluid for heat as well. It would also play into the other suggestions about avoiding freezing issues in the water tanks. The other downside? I'm not sure the dual loop tank heaters exist either.

Reality may force me to combine the two concepts. I would be inclined to have a tank heater plumbed into the engine cooling system and take advantage of the waste heat to heat water. In addition, a hydronic system might be used to heat water in another tank heater. A selector valve could be used to toggle between them based on what was already hot. It'd be a bummer to heat a full hydronic system on a hot day to just take a shower if the motor side is already cold, but it would be the system which does everything.

I have stumbled across the Aquahot products while casually surfing as I write this post. They sound awesome but good grief they are expen$ive... Are they gold plated?

Definitely open to suggestions, recommendations, etc...
 

NavyNuc84

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Starting to poke around the internet for water heater stuff and found this:


This fits the bill for the two coil water tank, one loop with the engine coolant being circulated and the other fed by an Espar or other hydronic heater. This also has a 12V electric element which I've also seen controllers use as surplus solar loads if the batteries reach full charge and there's still sun shining on them. A unit like this is appealing.

Still thinking about how it (the Espar) might be plumbed to be able to pre-heat the motor if desired, but that should be possible. It would likely require a handful of valves to divert flows but shouldn't be too complicated. I would prefer to keep them separated as to not put too much of an additional load on the engine's coolant pump and I want to make sure there's a sufficient bypass that the Espar's pump isn't going to burn out pushing against a closed thermostat. It's all been done before so I am certain it's possible, but I want to make sure I'm not introducing extraneous issues.
I'm using this Oasis Zephyr – Itrheat with dedicated engine preheat loop. Great footprint (mounting outside below habitat).
 

coachgeo

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I'm using this Oasis Zephyr – Itrheat with dedicated engine preheat loop. Great footprint (mounting outside below habitat).
Im not really a welder but geez... the welding on this tanks pic looks like shiat??

why all the trouble using a calorifier... as expensive as they are. They are old school in method. IMHO just use a very well insulated 5-10 gal LP / 12v (converted to 24v elements) Electric RV water heater but have the fill system go thru a coolant/water heat exchanger. If you want to reheat every once in awhile with coolant..... plumb the drain line to cycle back thru the heat exchanger and put a solenoid on it to open/close it as you see fit.
 

NavyNuc84

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Im not really a welder but geez... the welding on this tanks pic looks like shiat??

why all the trouble using a calorifier... as expensive as they are. They are old school in method. IMHO just use a very well insulated 5-10 gal LP / 12v (converted to 24v elements) Electric RV water heater but have the fill system go thru a coolant/water heat exchanger. If you want to reheat every once in awhile with coolant..... plumb the drain line to cycle back thru the heat exchanger and put a solenoid on it to open/close it as you see fit.
That is the other advantage to ITR Heater....it is instant hot water heat. No need for a calorifier/hot water heater. I'm a sailor and so had a similar setup in my boat.
 

coachgeo

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That is the other advantage to ITR Heater....it is instant hot water heat. No need for a calorifier/hot water heater. I'm a sailor and so had a similar setup in my boat.
do not know what an ITR is but yeah.. agree instant is better .... especially if you add a recirculating valve to push the not yet warm water back to the water tank. Most full time RV'rs end up going that way now.... But at same time understand that why not capture coolant heat and store it. Question is does the devices to capture the coolant heat add up to so much money (and more to go wrong) that it does NOT offset the expense of paying for the energy to heat the water w/out it.
 

NavyNuc84

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do not know what an ITR is but yeah.. agree instant is better .... especially if you add a recirculating valve to push the not yet warm water back to the water tank. Most full time RV'rs end up going that way now.... But at same time understand that why not capture coolant heat and store it. Question is does the devices to capture the coolant heat add up to so much money (and more to go wrong) that it does NOT offset the expense of paying for the energy to heat the water w/out it.
The Heater does capture engine heat. I went this route because when I calculated footprint and cost for a Webasto, Calorifier, heat exchangers, Solenoid valves it didn't make sense. I'm probably going over the top with this system...but if you want to be able to preheat engine while boondocking...can't beat it.
 

ckouba

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Question is does the devices to capture the coolant heat add up to so much money (and more to go wrong) that it does NOT offset the expense of paying for the energy to heat the water w/out it.
We may be experiencing a philosophical difference George. Generating hot water while underway is a no-brainer to me. I am not building this camper to waste money but I am also not building this camper to save money, and I understand amenities cost money. Down the road, I don't think I'll remember that I paid $500 for a calorifier, but if I pass on it, I will be reminded of that every time I turn on the heater and wait the extra 40 minutes and burn fuel to heat the tank. Or wait even longer and worry about the extra load on the solar if trying to do that through a 12V/24V element (if it's even possible). I don't see too much additional complication or risk in a second loop through the calorifier.

I took a quick look at the ITR site but didn't see any detail pics regarding the weld quality but if it has the full spectrum of benefits as NN84 indicates, it will be a strong option. Need to investigate pricing as well though.
 

NavyNuc84

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We may be experiencing a philosophical difference George. Generating hot water while underway is a no-brainer to me. I am not building this camper to waste money but I am also not building this camper to save money, and I understand amenities cost money. Down the road, I don't think I'll remember that I paid $500 for a calorifier, but if I pass on it, I will be reminded of that every time I turn on the heater and wait the extra 40 minutes and burn fuel to heat the tank. Or wait even longer and worry about the extra load on the solar if trying to do that through a 12V/24V element (if it's even possible). I don't see too much additional complication or risk in a second loop through the calorifier.

I took a quick look at the ITR site but didn't see any detail pics regarding the weld quality but if it has the full spectrum of benefits as NN84 indicates, it will be a strong option. Need to investigate pricing as well though.
 

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coachgeo

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much thanks.... gives me ideas on how to install my old school coolant military diesel heater and smaller china heater coolant side for just bunk or low heat
 

ckouba

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After getting lockers installed, it seemed like the best thing to do would be go test them. I went back to something I tried when I first go the truck which I needed a few attempts to clear. This time was right up and over without issue. Felt great!

While I was out, I took a few pictures in the open with the subframe on:




And then when I got back, I did the best I could to articulate the suspension to see what the subframe does. I stacked 2 dead tires and drove over them. In all honesty, the frame flexed a little more than I thought it would, but the subframe is clearly doing its job:




Will get back to serious fabrication in the next week or two. For now, VERY happy with the locker install! Thanks Bryce!
 

Mullaney

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After getting lockers installed, it seemed like the best thing to do would be go test them. I went back to something I tried when I first go the truck which I needed a few attempts to clear. This time was right up and over without issue. Felt great!

While I was out, I took a few pictures in the open with the subframe on:




And then when I got back, I did the best I could to articulate the suspension to see what the subframe does. I stacked 2 dead tires and drove over them. In all honesty, the frame flexed a little more than I thought it would, but the subframe is clearly doing its job:




Will get back to serious fabrication in the next week or two. For now, VERY happy with the locker install! Thanks Bryce!

Nice looking! I know I have seen the build as you have gone along - adding the frame and subframe. Definitely making progress! I can't wait to see more!

Tim
 

Third From Texas

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Im not really a welder but geez... the welding on this tanks pic looks like shiat??
You should see *my* welding ! LOL

I can't say for sure, but I'm not certain that is a weld. Look closely at the base. Some kind of molding process is present at the bottom (and may explain the oddness at the upper seam). Maybe an external secondary layer of tank that encapsulates a (plastic or epoxy) insulation ?

Or maybe their metal-gluing guy sucks at it like I do.

/shrug

;)
 

ckouba

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I needz dat antenna !
Antenna itself (there are different colors to choose from):

Mount:

I originally got a 9' whip antenna but that ended up way too far into the trees. This brings it down so it's not hitting trees, stoplights, or power lines (just kidding), but the larger size increases the aero drag and bends it back a bit. I need to somehow secure it upright but haven't solved that problem yet.
 

Reworked LMTV

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After getting lockers installed, it seemed like the best thing to do would be go test them. I went back to something I tried when I first go the truck which I needed a few attempts to clear. This time was right up and over without issue. Felt great!

While I was out, I took a few pictures in the open with the subframe on:




And then when I got back, I did the best I could to articulate the suspension to see what the subframe does. I stacked 2 dead tires and drove over them. In all honesty, the frame flexed a little more than I thought it would, but the subframe is clearly doing its job:




Will get back to serious fabrication in the next week or two. For now, VERY happy with the locker install! Thanks Bryce!
Sure looks solid! I like the dual upper and lower springs. Did you source those from McMaster Carr?
 

ckouba

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Sure looks solid! I like the dual upper and lower springs. Did you source those from McMaster Carr?
Close.... Grainger. Look up die springs, lots of lengths and rates to choose.

I will end up replacing the upper springs on the aft 4 perches with shorter ones- actually going to use the springs from the first set of perches in the upper positions. Originally I was going to insulate and build the floor on top of the subframe structure but now will be bringing the external envelope around the bottom of the subframe instead. Need to drop the springs down so they clear the cabin skin.
 
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