Current HWH options/opinions?

[kbeefy]

Prepping for a new van build.


Up in the air how to heat water....


Short-term Boondocking, dispersed camping. Usually 3 days maximum. Just dishes, handwashing and occasional outdoor navy showers. Occasional extended roadtrips, longest so far was 10,000 miles/60 days.



I originally wanted propane/110v/motoraid, but I feel it will be overkill. My current class A has motoraid and it's awesome, but only for a few hours after parking.
Previous campers had suburban propane heaters that worked well.


I don't want electric for primary water heating, primary boondocking. so propane is primary. Hydronic is a nice benifit but maybe not necessary.


I have a toyhauler with on-demand and it is spotty. I plan on installing a recirc system to make it more useable.




So, I guess my question is on-demand or storage water heating, and is motoraid is worth it?


Part 2, what recirc hot water systems are people using and are they worth it?

[posplayr]

Originally Posted by kbeefy

Prepping for a new van build.


Up in the air how to heat water....


Short-term Boondocking, dispersed camping. Usually 3 days maximum. Just dishes, handwashing and occasional outdoor navy showers. Occasional extended roadtrips, longest so far was 10,000 miles/60 days.

I decided on propane because of the high energy density that does not demand electrical power. Planning on Under mount tank with remote fill E-350 EB.

As you mentioned there are several options. The tankless HW is smaller and more efficient than the conventional WH.

I have debated having something in between which is a Tankless with an accumulator to preheat prior to a shower.

I posted but received no comments here. I already have a heat exchanger and have rear A/C unit. I plan to put a hot water cutoff for the summer.

In the picture, I assume there is an accumulator tank (1-2 gallon) after the Tankless heater.

https://www.sportsmobileforum.com/fo...tml#post318251

I have not doesn't any of this but it would seem to serve various purposes across seasons and is not too hard to do.

[b. rock]

If you get a diesel van, I've poked around at a combo engine heater/hydronic heater. Use the same glycol loop, then a little HX to transfer to a HW system. Basically same thing as the motor aid style, but can run w/o the engine, and also preheat your engine, and if you put a coil inside - heat the van too.

[kbeefy]

Originally Posted by b. rock

If you get a diesel van, I've poked around at a combo engine heater/hydronic heater. Use the same glycol loop, then a little HX to transfer to a HW system. Basically same thing as the motor aid style, but can run w/o the engine, and also preheat your engine, and if you put a coil inside - heat the van too.

I had read about putting a pump inline to also warm the coolant, but I didn't even think about a cabin heater, like big trucks use....




I do plan on getting a diesel.

[b. rock]

Heat is heat. Just depends on how you want to do the exchange. Air to air, air to water, or water to water.

That's my plan if I keep my van.

Edit: worth noting that I already have a shuttle style rear heater box, so all I need to do is take over the fan control. Might be slightly more complicated with the Ford rear unit, not positive.

[kbeefy]

Originally Posted by b. rock

Edit: worth noting that I already have a shuttle style rear heater box...

You just reminded me I have an aftermarket heater box thats been sitting on the shelf for years. I just may incorporate it into this build!

[86Scotty]

Big truck cabin heaters are Espar/Webasto type units, the 'CDH' style small diesel furnaces that everyone has been going to in camper-van world for the last few years.

I recently bought a Lavaner for my new van build, which is about the best quality Chinese made one available so far as I know, and it is very nice. No winter experience yet but the parts/unit quality is certainly as good as my work truck Espar D2. The price is about halfway between the cheap Chinese ones and the very pricy Espar/Webasto units.

For commercial applications up until recently all there was was the Espar/Webasto units with some Planars around but not very popular in the US. If you go poking around pretty much every 18 wheeler on the road you'll find an Espar D2 usually paired with a Thermo-king or similar APU for charging and air conditioning. Their use of Espar is fully incorporated in to the climate control system and works off the same wall mount controller and wired from the APU's main board in most cases.

You say you don't want electric but why not if it's DC? I recently took a small under sink tank (NOT tankless) HWH and swapped it to a DC element and it gives me reliable hot water at a fairly low cost. Mine is a 6 gallon unit (overkill like I wanted) but the small 3 gallon ones are a popular #vanlife hack swapping the AC element to DC. It keeps water warm overnight. Our plan is to run it while driving and have residual hot to warmish water for overnights.

[arctictraveller]

On the other hand I get all the hot water I need by heating it on the stove in the coffee pot, except for showering when I use a solar shower. If the solar shower hasn’t had time to heat up, I just add hot water from the coffee pot. It helps conserve the limited amount of water I carry too.

[kbeefy]

Originally Posted by 86Scotty

I recently bought a Lavaner for my new van build, which is about the best quality Chinese made one available so far as I know, and it is very nice.

That was my original plan, but now b. rock has me thinking about an Espar.
For alot less money I might try one of these...


https://www.ebay.com/itm/26631700261...3Avlp_homepage

Originally Posted by 86Scotty

You say you don't want electric but why not if it's DC?

It's a pretty big electric load, I would think. 100w heating element x 12 hrs = almost 100A.


I just reread your message, your just running it while driving, right? That would be fine then, but I'd be curious about how warm it is in the morning.

[1der]

HWH is such a luxury and such a pita to figure for a van based rig.

"Instant" electric - only if you have an incredibly large Lith bank and a way to recharge that size Lith bank.

"Instant" Gas - heat exchanging plate - still takes time as there is no stored hot water.

Our current setup is a SPA 15 - 4 gal tank with both a 120vAC 750w element and a custom 12vDC 230w element. The SPA15 holds water at 160F and uses a mixing valve to temper the water at the faucet. That part is nice since in effect we have a true 4 to 5 gals of nice hot water when we arrive at a campsite and into the next morning depending on how much hot water we use and if I want to re heat the water via a Lith battery drawdown. Depending on the duration of our drive, while driving, I will use the 750w AC element via the inverter which heats the 4 gals to 120 in about 1 hour., 160 in about an hour and 45 minutes. Or, on a longer trip I use the 12vDC 230w element for about 3 to 4 hrs. I have not bothered to hook up the available motor assist loop due to primarily due brining very hot pressurized coolant into the cabin.

Things get more challenging on Day 2 and later if we are not driving, or driving for a couple of hours. If there is plenty of sun hitting the 400w solar panel then the 12vDC heating unit generates a nice rise in heated water everyday. If it is snowing or shaded then we are back to heating water on the butane stove for subsequent stationary days. Not bad, but not as nice as hot water on tap at the sink or rear shower.

Water conservation (recirculation) related to waiting for the heated water to dispense from either fixture is done by capturing the water in a clean container and pouring it back into the water storage tank. We have an easily accessible large 3" diam filler port with a screw cap which makes filling super easy. Without some type of additional water pump (with ability to handle hot water) a true recirculation system would not be possible, as far as I can see.

Above is our current system.

I think many people think a 4 gal regular hot water heater is going to work. It will provide about three gals of diminishingly hot water as the tank is replenished w cold/ambient temp water. Maybe 2.5 gals of "hot" water. This where a 160F water storage and a mixing valve provides an even temperature of hot water through the 4 or so gals before starting the temperature drop off.

Some other approaches / potential mods:

One way to handle subsequent stationary with no solar days would be to install a hydronic water heating unit and running its output through the motor assist loop. Essentially, "Motor Assist" with a separate hydronic heater. This would heat the water in the SPA 15 to usable hot, I am told, in about 30 mins. This set up can be made even more functional (and more complicated) by adding a heat exchange plate as well as an engine coolant heating connection. Lots more valves and connections.

In an upcoming build I have been looking at the offerings from Aquahot. Their system is a multi heating source (electric/motor assist/ fuel) hot water system with ability to also run cabin space heating loops via thermostat controlled radiators (multiple zone capable) that the hot water is passed through. From what I see they use a 2 gal hot water storage tank with a hydronic heating unit that mounts below the floor. I need to do more research. I am not a fan of using hydronic to heat the cabin. Airtronic units are far less energy (no water pump, only a fan) and thus quieter.

One of our vans came with the 6Gal Atwood AC electric/motor Assist/ propane water heaters in it. If driving water is being heated. If connected to shorepower, flip the breaker on. If dispersed turn on the propane burner. Works great. Also comes with a big hole cut in the side of the van.

From what I can determine so far, the AquaHot 125 can do what the Atwood does using gasoline or diesel (no propane tank needed) as the heating source and no hole in the side of the van (but a significantly bigger hole in the wallet).

They're also the straight hydronic to heat exchanging plate systems. Very space efficient and provide unlimited hot water after it has warmed up the plate enough. I have no real world experience with these. Heat plate freezing and cracking is a concern depending on where the heat piste has been mounted.

Then there are the Joolca style instant propane units. While really only for outside use, some have been installed on the inside of rear doors. These set ups are primarily for showers and use with doors open to allow the exhaust gases and heat to dissipate. They are excellent well proven water heating units but do not really lend themselves to a four season van "hot water system". Thoughts around making these units more usable in an integrated system have been to incorporate them mounted to an outside box / compartment and plumb the connections (hot and cold) into the in cabin plumbing. Certainly is not going to work in freezing weather.

I would love to hear more ideas people have! We use our rig in all seasons and significantly through winter. Right after a great cabin heating system, turn the tap for hot water is really nice!