On demand tankless LP water heater

[IanC]

I've been looking at some of the portable tankless water heaters such as Ecotemp. They say 'for outdoor use' but then the one I was looking at says 'ca be mounted above the sink '.  I was wondering what the reason for that is. Could it be a venting issue ? I'd like to mount it inside my build, but I suppose I could mount it inside a box on the front of the trailer above the gas tank and lead a connection into the interior.

 

[highdesertranger]

keep in mind, "not for indoor use" is on all propane camping appliances. just say'in. highdesertranger

 

[LeeRevell]

Some do mount them inside, which is alright if you have adequate ventilation, like any non-vented gas heater.  Been looking at one myself.

 

[Optimistic Paranoid]

keep in mind,  "not for indoor use" is on all propane camping appliances.  just say'in.  highdesertranger

I believe the reason is that all indoor appliances have built in safety features that shut off the gas if the flame blows out.  Camping stuff doesn't have those.  I know this is true re gas ranges vs camp stoves, I'm guessing it's also true in other appliances.

 

[BradKW]

It seems to come down to a venting issue with these units...I've been playing around with the idea for a while now and have consequently been paying closer attention to the home units I see on jobs. The house/apt sized units kick out a good bit of exhaust and I've been tempted to get one of those little "camping" ones to play around with it.

You can use propane appliances inside as long as you provide adequate ventilation. You have to ensure that the heater has adequate ventilation for combustion as well as ventillation to allow the products of combustion to escape. If you burn propane once with an adequate air supply, you will only be producing water vapour and carbon dioxide. But if you reburn those gases, you will now be producing carbon monoxide in a large way.

So my basic idea is to have a sealed off back corner that will allow for intake and exhaust, and I'm hoping to come up with a design that services a propane tank vent, tankless heater, battery venting, and an interior mounted AC unit. I've seen portions of this in builds, but not all...and it may well be that mixing batteries, open flames and possible tank out-gassing can't be done right in a single ventilation system.

 

[IanC]

I was also wondering how hot the unit, itself gets. I was thinking of mounting it on a shower wall sheathed in fiberglass panel, so if the unit itself gets hot, that could be a problem. I wonder if housing the unit in a box, like a small breaker box with just the fittings coming out the bottom and the box vented to the outside would be an option


It seems to come down to a venting issue with these units...I've been playing around with the idea for a while now and have consequently been paying closer attention to the home units I see on jobs. The house/apt sized units kick out a good bit of exhaust and I've been tempted to get one of those little "camping" ones to play around with it.

 

[BradKW]

They don't get the mounting surface hot. They use your basic metal standoffs/ heat shield and are mounted on wood siding...

 

[masterplumber]

There are various Eco Temp models, some are vented and some not - well they are, but it's built in and can't be run outdoors. I have some friends with an off grid place in the mountains I've been working on. They bought 2 of the units - one for the bathroom and one for the kitchen. There are a couple issues to be aware of - 1st, do you have enough water flow? They work on a flow switch so you may need a bigger pump, and an accumulator tanks to smooth out the flow. 2nd, at what altitude do you plan to spend most of your time. The units my friend has are still in the box because there place is at about 9000 foot elevation. From what we can find they don't seem to work much above 6000 feet. We're trying to find out from Eco Temp if we can redo the orfices or something to get it to work, but so far no answer. This makes sense when you consider gas/oxygen ratios to create a flame. I know my Mr Buddy heater will work pretty well at 8500 feet, but I can hardly get it to stay lit at 11,000 feet.

 

[Mobilesport]

L5 mounted into Express van 40 door.
The exhaust chamber is completely sealed until I open the 40 door window , then the L5 exhaust out the window. 
Shower pan Is hidden under the floor (recessed 
Floor opens up on hinges

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[IanC]

L5 mounted into Express van 40 door.
The exhaust chamber is completely sealed until I open the 40 door window , then the L5 exhaust out the window. 
Shower pan Is hidden under the floor (recessed 
Floor opens up on hinges

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Clever set-up

 

[BradKW]

Very nice Mobilesport! Could you talk about what your experiences are with that setup, how you use it, etc?

 

[Mobilesport]

Very nice Mobilesport! Could you talk about what your experiences are with that setup, how you use it, etc?

At shower time I open the floor to expose the shower pan , there's 2 shower walls inside that fold out like monopoly boards (they are clear rigid plastic.  
I hold the walls in place with spring clamps
The 60/40 doors are water poof .
I flip a toggle switch that sends 12 volts thru a standard 30amp automotive relay to power the water pump  , when ever the switch is in the on position ,  water is pumped out of a 6 gallon green jerry can thru a clear tube with water screen  , when ever the ecotemp senses water it automatically heats the water as its going thru. 
I keep ecotemp water flow adjusted to max at all times. 
Toggle switch is mounted upside down by the ceiling so water don't run into it, obviously its reachable. 
I only use the temperature adjusment knob to dial in my desired temp.
During winter shower pan is cold so I fill a cup with boiling water and splash it on the shower pan to make it very comfortable on your feet and then dial temp back down to desired temp for showering
I forgot to mention I must open the 40 doors window because I built a chamber of the upper 40 door , from outside you cant tell there's a water heater vent .
I still need to add a cover to cover the 40 doors window lever  it will mount flush because the window lever does' ntstick out when the window is open   for the time being I've just been covering that window lever hole with a peice of cardboard and tape , finished product will be a piece of sheet metal and a hinge and latch or magne

 

[Mobilesport]

The L5 takes up almost zero space since its inside of the 40 door , I was thinking of installing some kind of water bladder inside the 60 door
You could use it as a outdoor shower if you wanted to , I don't shower outside but i do use it outside to wash my hands after working on the vehicle.

 

[masterplumber]

Very nice Mobilesport. What size pump do you use? I really like the hidden vent design.

 

[Mobilesport]

Very nice Mobilesport.  What size pump do you use? I really like the hidden vent design.

I bought the water pump from Northern tool.
Model 2682271B
The Brand is Northstar  ,,, pumps 2.2 gallon per minute

I really like the hidden vent design too but I need to fabricate some kind of waterproof cover to cover up that shiny hvac foil tape ,, I dont like looking at that tape.

 

[Ballenxj]

I wonder what the propane consumption rate is? This is a neat idea.

 

[Mobilesport]

The L5 takes up almost zero space since its inside of the 40 door , I was thinking of installing some kind of water bladder inside the 60 door
You could use it as a outdoor shower if you wanted to , I don't shower outside but i do use it outside to wash my hands after working on the vehicle.

Ive noticed this Ecotemp tends to shoot a flame out the bottom every once in a while,  I made sure my gas fittings were leak proof and i also was very careful not to overthighten the gas fitting. .
Since this heater was engineered for outdoor use I'll probably will pull it out , I ain't willing to risk it.