hydroponics water heater .... what ya think of this idea ?

[225digger]

so im a newb . tons of reading over the past yr about tears , and im about to start making my own . i know it wont take much to heat a tear , but heres an idea . im going to install a 6 gal propane water heater , me and the wife both need our little comforts and hot water is a must , so heres what im thinking , put a t before the hot water heater inlet and then a t on the outlet , with a pump on the outside this water would push through a mojave car heater {there 12v} picture below . then the water would return to the water heater to be heated again ..... i know i will need to find a water pump that can handle the hot water which shouldnt be an issue . but whats the thoughts on this ? the water pump and mojave fan would be 12v so there would be minimal power loss , i could make up a thermostat system to turn the pump and fan on at the same time .

im not sure if anyone ever thought of this or has attempted it , but i think it will work well

thoughts ?

[GuitarPhotog]

How much current does the pump take when running?

Are you planning on running this only when hooked up to shore power or off your trailer battery?

<Chas>

[48Rob]

Propane water heaters can be noisy when the burner is on (like a mini jet engine).
That said, my propane furnace isn't quiet either...
The pump and fan will draw a fair amount of power.
It might work okay, but you may need a large propane tank and an extra battery(s) depending on how cold it is while camping.

It is an idea that has been discussed several times, but I don't recall anyone here actually following through?

Rob

[GerryS]

Welcome to the fun . I see only two posts.

Not a bad idea. Unless your boondocking something I've never one. State paks almost always have power in our part of he world.... Power will be an issue. Pumps inconvenience a significant number of electrons to run.

How often are you cold weather camping? I've done a couple freezing nights, with just me in the camper under a down comforter I was comfortable. I'd recommend a knit cap though. Even though it was below freezing outside, inside only got to the mid 40s, with 2 it wouldn't have gotten that cold I'm sure. The human body puts out quite a bit of heat.

A small space heater (the ceramic type) got my living area up to 70s in just a few minutes. Leaving it on will bake cookies A $20 heater that you can leave at home in the warm weather is a lot easier solution that a heater coil etc. you'll probably find having that cubic foot of storage available is worth the trade off....unless you also plan on using it to heat domestic water as well....but again, my stovetop does that. We usually only heat a pot and add it to a sink of cooler water to get warm water to wash dishes etc.

When we started our planning, we thought we'd need hot water too....I've never regretted leaving it out of out plan. My AC on the other hand, I couldn't do without....

We've got a campinn ultra 560 now....

[Socal Tom]

I like the idea, but I share some of the concerns voiced above. The fan on the mojave heater will pull a fair number of amps. ( what I found on-line says 19.5 amps) . For a water pump I assumed this one from harbor freight http://www.harborfreight.com/12-volt-ma ... -9576.html. It says it draws 50 watts. ( I believe thats about 4 amps). So now you are at 25 amps for your system.....

That said, if you are doing a water heater anyhow, the mojave would be a reasonable way to add some heating, but I would use it sparingly. Like only when on shore power, or just to heat up the TD in the am before you climbed out of bed, or warming up the bedding before going to sleep.
My one experience with snow camping as a boy scout, we were in backpacking tents, camping on top of about 2 feet of snow and it was in the 20's overnight. I boiled some water and filled my canteen and wrapped a towel around it and stuck it in my sleeping bag. I slept like a rock. Other scouts that didn't take my advice shivered all night long. The point of my story being once we got our sleeping bags warm we could maintain it just fine, I think the same would be true of the inside of the TD.

If you do this I recommend adding a flow control valve ( not a ball valve) between the pump and the heater so you can adjust the flow rate to get max efficiency out of the system. ( The water coming back to the water heater should be as cold as you can get it). Reducing the flow rate on the water pump will reduce the amps it pulls, and if you get all the heat out of the water in a single pass, then you will be running the fan for less time.
Good Luck,
Tom

[pmowers]

It sounds like you are putting thinking about putting in a miniature version of steam heat or a car heater. Before you are set on the water heater, may I recommend standing next to one at a campground and listening when it is heating. It is quite loud, and do you really want to have that heater on all of the time? Additionally, the temperature difference may not be all that much, as most of the heaters only reach 120 degrees or so. Your car heater runs off the engine temp, at about 180 or more.

As I have "matured" I have become much more demanding of creature comforts. My "living out of a ruck days" are behind me, and I only go to campgrounds now. When I did my cargo trailer conversion, I considered putting in a hot water heater, but decided to put it off for the future. Other than washing hands, face and dishes, I really did not need it. Taking a shower at the site is nice, but you can run into alot of problems with waste water disposal- how are you going to collect it, hold it and dispose of it. Most people can't do it in just a gallon of water. As far as heat goes, I just use a ceramic heater to heat the interior of the trailer, and as Gerry said, you could bake cookies in there after awhile.

You did not say if you are boondocking or will be using campgrounds. I am assuming campgrounds as you did not mention large storage tanks and pumps to supply water. I would look at some of the small demand systems which can use a small 1# cylinder, and provide hot water just when you need it. http://www.youtube.com/watch?feature=player_embedded&v=amQehfJJgUk As others have pointed out, there are a lot of additional items and weight to consider. Once you take the chill off, body heat really warms up the small space inside a tear or TTT.

[225digger]

thanks for all the input , i understand how loud the water heaters are , i have a 36' class A with a 10g heater , its not tooo bad , inside you cant hear it , so i will try and seperate the heater from the inside the best i could with some fiberglass sound deadner or something . i have alot of thinking to do on this , so i might do it or i might hold off till after the 2 week trip out west and see how it really is . we stayed in north west wyoming alot and it can get cold at night , and thats where we will be staying a few nights so i might just suck it up and deal with it

That said, if you are doing a water heater anyhow, the mojave would be a reasonable way to add some heating, but I would use it sparingly. Like only when on shore power, or just to heat up the TD in the am before you climbed out of bed, or warming up the bedding before going to sleep.

thats what i was thinking , maybe just run the heater at night and then in the morning , me personally i like it cold to sleep , but that transition from nice cuddly blankets to cold is a shocker so the heater would work well for this .


My one experience with snow camping as a boy scout, we were in backpacking tents, camping on top of about 2 feet of snow and it was in the 20's overnight.

i remember those nights to , how can you ever forget them ? our troop was very active , camping atleast 1-2 times a month all over the north east , i am an eagle scout so i went through it all ... never got to do the OA becuase i had other ventures going on that didnt allow me .

You did not say if you are boondocking or will be using campgrounds. I am assuming campgrounds as you did not mention large storage tanks and pumps to supply water

there will be boondocking , the whole reason for this tear is becuase me and the wife want to do a trip west which would include 2 weeks of travel to hit rapid city area , onto cody /redlodge , through yellowstone , into jackson , over the pass into salt lake city , then south to the desert and back home . we did it 3 yrs ago in our motohome , but i had help driving so the 5k mile trip wasnt bad , but this time its just me and the wife and she cant drive the 36' mh with dingy. but anyways when we travel like this we dont make plains anywhere , we just go and where we end up for the night thats it . sometimes we get lucky and have a camp site , sometimes a hotel room , sometimes a parking lot . but having the tear with some ammenitys will help us stay in more remote locations instead of needing to drive out of the way to get somewhere bette


.but anyways , i was just thinking of this as a heating idea . there will be a water tank and a pump to feed the water heater .


we plain on doing this trip sometime in aug so i might hold off on this idea till after this trip , but it easier to plain for it than not plain for it and have to hack stuff apart .

[Shadow Catcher]

My feeling is that it is overkill. I have been thinking about this for some time and think a computer case fan (less than one amp) and a salvaged heater core with a small high temp solar water pump i.e. http://compare.ebay.com/like/1809244083 ... s&var=sbar would be more than enough heat. From personal experience a 6gal hot water heater is as suggested much like a small jet engine in a small space. I turn ours off at night.

[225digger]

i thought about the small fan idea also , im a tinkerer i love to make as much stuff as i can , and since i have a full fab shop i can make almost anything from metal as well as weld it so i might come up with some other alternative . i think for this trip im going to bypass the hydronic heater idea but make provisions for it in the future , i am however installing the water heater is a requirement for me and the wife . we can deal without heat but hot water is a must .

[Bogo]

I've thought of doing it too. Instead of using an already made fan and heat exchanger, my plan was to use a computer fan blowing through a CPU water cooler radiator. They can be found for 1, 2, & 3 fan sizes. A good quiet fan would draw under an amp. Search at Amazon and you can find a bunch of the CPU cooler radiators. A thing to lookout for is how high of temperature your pump can handle. I figured on using a 1 gallon per minute pump.

[mezmo]

Hi 225digger,

Here are some links that you may find useful:

Some European hydronic caravan/rv heaters:
ALDE
http://rv-pro.com/news/rv-supplier-sees ... ing-system
http://www.alde.co.uk/
http://www.alde.co.uk/alde-compact-products.php [Illustration]
http://www.alde.co.uk/itemdetails.php?itemId=1 [Details]
EBERSPAECHER
http://www.eberspaecher.com/nc/en/press ... d/419.html
ESPAR
http://www.youtube.com/watch?v=UjJ5m7uvJbE

Cheers,
Norm/mezmo

[Bogo]

Some European hydronic caravan/rv heaters:
ALDE
http://rv-pro.com/news/rv-supplier-sees ... ing-system
http://www.alde.co.uk/
http://www.alde.co.uk/alde-compact-products.php [Illustration]
http://www.alde.co.uk/itemdetails.php?itemId=1 [Details]

I was looking at the Alde Sigmar Dual-Coil Marine Calorifier which is linked to on the above pages. It would likely be better to go with a IsoTemp unit because of how long they keep the water hot. http://www.indelwebastomarine.com/home/ ... /7957.html

For plumbing, I'd pump the water from the boiler through the engine heating loop in the calorifier (water heater), then on to the radiator coils, and then back to the boiler. That way the hot water is heated to full temperature every time heat is needed. A bypass to bypass the heater coil will be needed for summer use. An expansion tank will also be needed. Calorifiers are really meant for situations where there is an engine to scavenge heat from. Great for a boat or RV, not so good for a trailer. A water cooled genset could be plumbed into the loop with valves so it heats the water when on.

In general calorifiers are setup to heat the water as much as possible, then a temperature adjust valve is used to lower the water to safe temperatures. Because of this a 5 gallon unit usually will provide around 7 to 10 gallons of full temperature shower or dish water.

The biggest issue is cost. The boiler will be costly, well over $1000, then the calorifier to get hot water will add another $700+ on to that. Yeah, they are expensive, but they are made for the marine environment. I think the lowest I've seen a boiler for is $1200 and that was diesel fired, deeply discounted, and only 5k BTU. That is why I've looked at using a regular RV water heater.

[Wild Turkey NZ]

I like the initial idea!
I tried making a heating system. i used computer fans and a oil cooler for the heater unit and a wet back in a small fire place as the water heater a small 12v camping shower pump circulated the water. http://www.tnttt.com/viewtopic.php?f=50&t=54738.

the problem i think you might incounter is not pulling enough heat out of the water. with a car heater unit the problem will be less. after you car is warmed up put the heater on full bore and reach under the bonnet and put your hand on the heater inlet and outlet by the fire wall. on my car the temperature difference is not alot but i can feel it.
for my heating system i have a old car oil cooler with two computer fans as my heater. they dont use much power and they have more than enough air flow to heat such a small space. however the water that comes out is only a few degrees cooler than when it goes in so my heating system just gets hotter and hotter. the first time i used it i just kept adding cold water into the system, as i only have a cheap little pump that is not made to handle hot water. it ran for 3 or four hours until the battery died. but in that time it knocked of the chill in the teardrop and heated it up to around 18 deg C (it was 0 deg C outside). i shut the system down when we went to be and we were warm all night just from out own body heat.

In my humble opinion i would not bother with a heater unless you had the money to throw at a propane heater(small, safe but loud). we spent a night when it was minus 8 deg C out side and we had a comfortable sleep without any heating.

if i was to do it all over again i would make a small stainless box in the tear drop that vented out the wall or roof that i could burn a few bits of charcoal in and had a couple of computer fans moving air around. cheap, simple, safe and quiet...next time.

[bdosborn]

Hmm, do you really want to run your drinking water through a radiator? I wonder if they use lead solder? This idea has been kicked around for years but no one has done it that I'm aware of. I went down that path during the design of mine but abandoned the approach when I thought of the drinking water issue.

Bruce