Heater Core Question for On Board Shower

Hey @2ski4life7 I'll sell you my Zodi propane heater for cheap if you'll use it. I wired it for 12v plug power so you don't have to carry giant d batteries around. It works great with the mini propane tanks or you can go buy a 5$ adaptor for a full size one.

I used it a couple times until I realized I could justify running a heater core through my engine.
You won't be able to build one that works better than the zodi one.

 

Thanks for the offer spencer. If I don't figure this electric heater thing out I will pry just go through the engines heater core. Thanks though!

 

@2ski4life


Here I did your homework for you

It's in metric but here's roughly what you're shooting for with this system-
Let's assume the coldest you can stand showering at is 40 degrees Fahrenheit (my engine powered has gotten me through several 30 degree trips)

Meaning your water cans will start off at 40 degrees. A comfortable shower is near 105 degrees, so you've got to bring that water up 65 degrees.

The propane heater and the engine powered type will reach that in under 15 minutes, so we will use 15 minutes for the time required to heat your water up
( who likes waiting for a shower anyways?)

We will also assume you and your lady (man?) will be needing to bathe, so let's use a 5 gallon volume to get that done.

SO.
5 gallons of water raised from 40 degrees to 105 degrees in 15 minutes brings us to a grand total of 1600 Watts of energy required to get that done.

Conservative factors:
I completely ignored the heat loss from the heater element to the water that will actually hit you out the nozzle, ignored any efficiency loss, and ignored any and all voltage drop from your truck and water pump running, so we will leave your volts at 12, time at 15 and your gallons at 5 for a fairly accurate real world calculation.

TL;DR:
Your idea would require an amp draw of 133.33. Even with the tow package from the factory you won't have enough power out of the alternator to perform this. Not to mention building a 1600 watt dc heating tank will cost you FAR more than using your heater core or buying my damned propane heater.

There is simply no replacement for the energy you can burn out of hydrocarbons.

 

? Huh?

 

Haha oh oh.
I really wish it would work but physics makes things difficult as usual..

 

Lol thanks for the calculations Spencer. I guess Ill start working on my heater core project.

 

It does take up space and weight and I suppose in some catastrophic event could be a fire hazard?
:dunno:

If you've got any questions, we'll be more than happy to help ya! It's tricky but so fuckin cool when you get it done. The only mod I use more than this one is my on board air.

Just move over to the on board water thread.

 

This is the thread. I started this one before finding the other one. They got merged and now all the real info is there as well as a couple other people that have gotten it done. Continue over there and you'll get plenty of help!

 

I just dont want to be carrying around a huge tank and more or less I just want to flip a switch and be able to shower instead of connecting a propane tank, etc. Although you have a good point in having propane for cooking etc. I think the heater core is the way I will go.

yeah Spencer I have been scouring that thread and the links this whole afternoon. Probably wont get to this for a month or two but have the ideas flowing just gotta figure out the good designs out of all and kinda make it into mine.

 

Good point. The whole flip a switch thing is exactly why I quit using my propane heater.
Another up side to the heater core project is not needing to carry water, so long as your destination has a source. I've got a hose I can drop into any water source, or hook the hose up to a spigot and have it run. Or I can hook up my water jug with the hose thread tap if I need to carry water.

Only issue I found with running a hose through a spigot is the heater core starts to act like a second radiator with very cold water and unlimited throughput- DO NOT run back to back showers without constantly monitoring your engine temperature. After 10 min or so it starts to pull the engine temp down too low.

 

When showering are you idling the engine at 1050 RPM like tweeek?

 

Yeah I don't wanna deal with controlling the throttle. I've seen a block of wood to hold the pedal down but eh my heat exchange is oversized and works great at idle. Overcooling seems to only be an issue when running a water hose because it puts more pressure colder water and unlimited flow instead of a lukewarm 5 gallon jug.

 

Maybe not more complicated but there are drawbacks. My zodi one comes in a box that you fill up and drop the little pump in. If you put a water hose in it would never heat up because it has to circulate for a couple minutes to heat up. External ones take forever too. The on board one takes all of 5 min to hook up a hose and the shower nozzle, but the portable one turned into a half hour ordeal setting up and waiting for the tank to heat up.

 

I had an ecotemp propane water heater. It's shortcoming and critical flaw is wind. There is a pilot light that goes out with a breeze and will anger you to no end. I played with it for an hour and sent it back. That was about 2 years ago...

 

I had the hot tap with case the first one listed. It comes in the red box which acts as a bucket . fill the bucket up and light the heater (I believe it's got a clicker and doesn't need matches) and let the pump recirculate till the whole bucket is hot.

I never had an issue keeping it lit, more of an issue with the fact that it takes a while to go from cold bucket to warm, then there's a 30 second window where you have to pull the shower head out and start using it, or it goes from hot to 2nd degree burn temperature.

Unless it's an on demand heating unit, most of these propane ones go like this

Pour water in bucket, set up heater, (did you remember fresh batteries?) take 5 min to light it,
Wait
Wait
Wait
Water gets warm, start to get undressed,
Oh crap now it's way too hot.
Stand there nekkid
Wait
Debate lighting it again
Start using it then it's cold by the end.
Put unit back in the garage, start gathering parts list for on board heater

 

What did you end up doing? I'm considering OBW as well but I'm not an engineer lmao.