After market rear heater advice please.

Early planning on a future Sprinter Van conversion Here is my idea for a bit of heat in the night. My van will have a 38 ish gallon 40 inches long inside the van under the sink/stove cabinet.
There will be louvers in lower cabinet area covering the water tank. Now if during the day one heats up the water tank to 85 degrees with a 300 watt fish tank heater, will the latent heat be
enough to keep the van from getting cold till morning. Solar power will charge the batteries during the day to power the converter.

mtbmitch said:

Early planning on a future Sprinter Van conversion Here is my idea for a bit of heat in the night. My van will have a 38 ish gallon 40 inches long inside the van under the sink/stove cabinet.
There will be louvers in lower cabinet area covering the water tank. Now if during the day one heats up the water tank to 85 degrees with a 300 watt fish tank heater, will the latent heat be
enough to keep the van from getting cold till morning. Solar power will charge the batteries during the day to power the converter.

Click to expand...

Interesting idea but heavy, 320 lb at total 3.3 of kWh capacity down to 40F (2.3kWh to 50F). Using material like ceramic tiles was common in the past to retain heat overnight with wood and coal stoves where weight was not a concern.

George.

mtbmitch said:

Early planning on a future Sprinter Van conversion Here is my idea for a bit of heat in the night. My van will have a 38 ish gallon 40 inches long inside the van under the sink/stove cabinet.
There will be louvers in lower cabinet area covering the water tank. Now if during the day one heats up the water tank to 85 degrees with a 300 watt fish tank heater, will the latent heat be
enough to keep the van from getting cold till morning. Solar power will charge the batteries during the day to power the converter.

Click to expand...

Its an interesting theory and will of course work a little bit, but I must ask what you think the btu rating would be and for how long.

I think im correct (but could be wrong) thinking I have heard tgat humans put out 200 btu and thats at 96 degrees constantly.

Your 85 degree water might stay 85 degrees but you would need to keep heating it 24/7. There is a lot of time between 6:00pm and 2am if you are not heating the water and to get heat your tank must shed heat which means your temps are declining constantly. I would think that you would maybe getting 100 btu out of that system?
When its 40 degrees out 5200 btu makes me happy.

Of course there are people that find the heat of a single light bulb is enough.

What is your theory on how much heat and how long it can last?
And what outside temps are you trying to stay warm in?

I had the same idea but abandoned it. I was afraid the warm water would have a tendency to grow bugs.

I also had the idea of placing my portable 5 gallon shower water beer keg under my bed platform at night. Mounted it there to see if it made any difference. It was worthless for heat.

Then I tried a 12 volt heating pad under my sleeping bag and let the van inside get cold at night. Bingo. That works very well with the exception of my head being cold. Body was very warm at either the #1 or #2 setting on the 7 position switch on the heating pad. Heating pad is a constant amperage with the varied amount of heat produce by changing the on and off cycle. So I still have 3-4 times more heat available for colder conditions. Electrical usage remained about the same. The reason is the refrigerator runs much less in a cold interior than in a warm interior. This solution is very quiet without an operating heater fan/burner and the refrigerator on time substantially reduced. I was using 7-8% of my 255 amp-hr battery capacity overnight with a warm interior and that did not change with a cold interior plus heating pad. The cold head problem was rectified with a snowboarders balaclava.

Another idea I had was to design the interior so that it can be partitioned off into separate areas so that the sleeping section is separated from the rest of the van. It would take less heat to keep the sleeping section warm if the remainder of the van was not heated. Refrigerator should be located in the cold part of the van. With my interior design, it would be easy to install a removable panel separating the front 2/3 of the van from the back 1/3 sleeping area. I did not proceed with this idea because the heating pad worked very well so partition was not required.

Graphite Dave said:

I had the same idea but abandoned it. I was afraid the warm water would have a tendency to grow bugs.

I also had the idea of placing my portable 5 gallon shower water beer keg under my bed platform at night. Mounted it there to see if it made any difference. It was worthless for heat.

Then I tried a 12 volt heating pad under my sleeping bag and let the van inside get cold at night. Bingo. That works very well with the exception of my head being cold. Body was very warm at either the #1 or #2 setting on the 7 position switch on the heating pad. Heating pad is a constant amperage with the varied amount of heat produce by changing the on and off cycle. So I still have 3-4 times more heat available for colder conditions. Electrical usage remained about the same. The reason is the refrigerator runs much less in a cold interior than in a warm interior. This solution is very quiet without an operating heater fan/burner and the refrigerator on time substantially reduced. I was using 7-8% of my 255 amp-hr battery capacity overnight with a warm interior and that did not change with a cold interior plus heating pad. The cold head problem was rectified with a snowboarders balaclava.

Another idea I had was to design the interior so that it can be partitioned off into separate areas so that the sleeping section is separated from the rest of the van. It would take less heat to keep the sleeping section warm if the remainder of the van was not heated. Refrigerator should be located in the cold part of the van. With my interior design, it would be easy to install a removable panel separating the front 2/3 of the van from the back 1/3 sleeping area. I did not proceed with this idea because the heating pad worked very well so partition was not required.

Click to expand...

Hi Dave, good luck in your selling and buying adventures. What was the coldest night at which your heating system, including cold mornings, was still OK?

George.

GeorgeRa said:

Interesting idea but heavy, 320 lb at total 3.3 of kWh capacity down to 40F (2.3kWh to 50F). Using material like ceramic tiles was common in the past to retain heat overnight with wood and coal stoves where weight was not a concern.

George.

Click to expand...

I agree. Cold air moved over an 85F tank without fins will transfer very little heat. I would also avoid having a tank of water which needs to be kept from freezing.

vic

So far the coldest has been 25 degrees. I suspect it will be fine at lower temperatures. I do plan on leaving space under van in my next conversion for a under floor Propex propane heater if I find that necessary.

I will not use an Espar after my 6 months campaign and $1300 cost to fix my original equipment Mercedes supplied Espar water heater. Many visits to Mercedes dealership to finally convince Mercedes that indeed they built my 08 Dodge and it was supplied by Mercedes with a factory installed heater. Became friends with my local Sprinter service adviser as he tried to get support from Mercedes to obtain the software required to troubleshoot the bastardized design. I have nothing but nice comments about how my local advisor doggedly kept trying to get support. He finally succeeded by going through a back door in the Mercedes system. In a way it was quite comical but in other ways it was BS.

If anyone is in the Santa Rosa area and needs Sprinter service, the adviser is Matt and he has your interests in his mind as he tries to support the Sprinter. I will miss the contact and honesty he displays.

Graphite Dave said:

So far the coldest has been 25 degrees. I suspect it will be fine at lower temperatures. I do plan on leaving space under van in my next conversion for a under floor Propex propane heater if I find that necessary.

I will not use an Espar after my 6 months campaign and $1300 cost to fix my original equipment Mercedes supplied Espar water heater. Many visits to Mercedes dealership to finally convince Mercedes that indeed they built my 08 Dodge and it was supplied by Mercedes with a factory installed heater. Became friends with my local Sprinter service adviser as he tried to get support from Mercedes to obtain the software required to troubleshoot the bastardized design. I have nothing but nice comments about how my local advisor doggedly kept trying to get support. He finally succeeded by going through a back door in the Mercedes system. In a way it was quite comical but in other ways it was BS.

If anyone is in the Santa Rosa area and needs Sprinter service, the adviser is Matt and he has your interests in his mind as he tries to support the Sprinter. I will miss the contact and honesty he displays.

Click to expand...

Sorry about your Espar or just Mercedes dissatisfaction. My current experience with Espar Airtronics D2 is very short and very good.

But my experience with gasoline powered Eberspacher was very long and very good. Started with the installation in my VW Westfalia in Germany and a few years later reinstallation into the Chevy Suburban. The Eperspacher went to other hands 10 years after the original install in Germany.

For Sprinters the D2 0.85-2.2 kW Airtronics is just about a perfect fit. In LP world only the Propex could compete successfully, I think.

George.

I would think the Espar heaters with Espar controls are a viable alternate. It is too bad that Mercedes made a poor engineering decision to modify a standard Espar and then not be able to support it.

I do think a heater that is fueled with a cleaner burning fuel would be an advantage compared to a diesel fueled heater.

It is unfortunate that I live in a temperate climate and have not had the opportunity to use the heating pad in colder temperatures.

We dry camp quite a bit here in Idaho. No need for AC in the summer up in the mountains. Temps are usually in the 40's at night during July and the freezing mark by November in the lower camping spots. I forgot to factor using up the 38 gallons of water. The electric blanket
running off some Lithium Ferrous Phosphate Batteries sounds like a good idea. Also going to use aerogel insulation and build the cabinets out of foam and fiberglass. I prefer to build lighter weight for the mtn. roads up here. Changing out the fiber glue and wood dining table for a foam and glass table went from 26 pounds to 3 pounds for example in the trailer.
The Propex or Espar heaters installed underneath are a great space saving idea that will
be on the potential build list. Watched a youtube video of euro rv vans. They really do alot with
the space they have.

HowardB said:

Its an interesting theory and will of course work a little bit, but I must ask what you think the btu rating would be and for how long.\

I think im correct (but could be wrong) thinking I have heard tgat humans put out 200 btu and thats at 96 degrees constantly.

Your 85 degree water might stay 85 degrees but you would need to keep heating it 24/7. There is a lot of time between 6:00pm and 2am if you are not heating the water and to get heat your tank must shed heat which means your temps are declining constantly. I would think that you would maybe getting 100 btu out of that system?
When its 40 degrees out 5200 btu makes me happy.

Of course there are people that find the heat of a single light bulb is enough.

What is your theory on how much heat and how long it can last?
And what outside temps are you trying to stay warm in?

Click to expand...

mtbmitch said:

The electric blanket
running off some Lithium Ferrous Phosphate Batteries sounds like a good idea.

Click to expand...

A 12 volt heating pad under the person is better than an electric blanket over a person. Heat rises. 12 volt DC also conserves energy compared to 120 volt AC blanket. No inverter running. Maybe you use a 12 volt electric blanket?

We've used our d2 for ten years now without any problems whatsoever on our 02 158".

Most of the use is in the daytime. We don't think it is necessary at night if the outside temps will stay above freezing. But we do some cold-weather and higher-altitude camping---the little d2 was fine for a 8F winter overnight in a deserted Delaware Water Gap campground.

Dave's electric bed warmer is a fine idea. We went in a more expensive direction with a 800 fill down comforter. It lets our 100w bodies manage without furnace or electricity in above freezing outside temps. Feels luxurious.

We typically bring along a 1800w ceramic cube heater as backup in case the d2 ever failed on a cold trip. We are normally drycamping but will haul it out on the rare occasion we have shore power somewhere.

Dan

Graphite Dave said:

My original heating system design was utilizing the Espar water heater option I purchased with the Sprinter. That ended up being more complicated than I expected. Had radiant heating hoses in the floor going back to a "truck cab" radiator/12 volt fan combination near rear doors. When I discovered I could electrically heat shower water in a beer keg that eliminated the need for a normal water heater system. Removed the radiant heating and radiator/fan. Now I use the Espar at night before going to bed and in the morning to heat van. During the night I use a 12 volt heating pad under the sleeping bag. Very quiet.

Click to expand...

Dave, what were the complicated bits about the "cab" style heater running off the engine espar? I am looking at an affordable way to heat the cabin and maybe domestic hot water. I like your sleeping pad idea, but would like warm ambient air in the van for crawling in and out of bed and lounging with coffee in the morning. My engine espar on an 06' is currently not working, but have only explored the low hanging fixes. It seems like a slick way to get heat, but I don't know much yet about controlling it, and getting through all the info here is pretty serious : ) thanks, chris

I purchased the 08 with the optional Espar water heater. Plan was to use that to heat van and shower water. I even bought the rear heating prep. option to get two pipes from system for future connection to my heating system. Bought a truck cab radiator/12 volt fan and mounted it in the rear of the van and had 5/8" heater hoses running through my 1 1/2" thick floor. First problem was the Mercedes installation has hot water in the pipes with the Espar running and engine off which I expected. What I did not expect was hot water in the pipes with Espar off and engine running. So that would require extra valves to prevent the hot water being inside during the summer.

During this same time frame I got in a discussion about heating shower water on this forum. The end result was the modification to a 5 gallon SS beer keg to produce warm shower water. Removed beer valve and dropped a 12v submersible pump into the tank and added a pencil 120 volt electric heater element with a thermostat. I get 5 gallons of 90 degree water after 45 minutes of driving. Perfect, no hot/cold mixing required. I have a 600 watt inverter powered by the Sprinter to provide the 120 volt power while driving.

At about the same time I decided to try the 12 volt heating pad instead of heating the whole van. That also worked well.

Result was I did not need the Espar to heat the van at night or to heat shower water so I took out the plumbing and the radiator. Now I use the Espar to heat the van in the morning when I get up. Works well for my application. Next conversion will have a 1000 watt vehicle powered inverter so I can add a 750 watt electric heater in back that can run with the engine running.

There is information on this site on how to rewire your Espar to operate without the engine running. You have a heater so why not fix it and use it?

I just purchased a D2 and Im deciding what location to mount it. I have a rear rear bath/Kitchen area with siding door thats tight on space. In the main cab area I have two bench seats with under storage that Im considering to use(close to tank) but I plan to use my sprinter as mobile office and I would prefer to have a really quiet space. I have a carrier low profile heat pump with ducting running above windows, I was considering routing Espar D2 into it but wouldn't want a unexpected backdraft into D2 to destroy it, any advice?
Thanks