o1, this topic usually turns into one of those "So's your old lady" arguments that no one seems able to agree on. I've posted on this topic many times but gawd help me if I can find one of them now--so here goes.
While my heater is the L5 and not the L 10 there will be size differences in the unit but the exact same mechanism of operation still apply. In short, I built a closed steel locker to house the heater in. Air of combustion (and cooling) enter from under the bus while exhaust (and heat) exit through a port high up on the side of the body No air of combustion comes from inside the bus and no ehxaust enters the bus. I installed a sealed access plate to allow for temp/flow adjustment and battery replacement and provided a remote placement of the on/off switch. My unit has been operating flawlessly now for nearly 5 years. The only "improvement" I've made on my installation was to install a recirculating system to prevent the endless on/off cycle of the heater and to conserve water while waiting for it to heat up. Of course since the recirculation of heated water back into the fresh water tank eventually raises the inlet temp at the heater -- especially when the tank is low, it is necessary to install a thermocouple switch of the desired temp at the outlet from the water heater to prevent scalding etc.
Here is where the "Ah pisha it'll never get hot enough to need all that metal surround" starts. Remember that wood begins to char at 450 degrees F after a few hours ignites. It immediately ignites at 700 degrees F. With the heater rated at 37,500 BTUs, those exhaust temps are easily reached.
01, the L5 is most definetly NOT an indoor unit and MUST have venting. It is propane fired and equally as dangerous indoors as the L10. I just checked my L5 owners manual and the unit as sold is only meant for outdoor use.
I always find these topics amusing as to "Oh my god it is a propane device and needs to be vented or it (Cue Doug Marcaida voice) WILL KILL you".
Yet nobody so much as peeps as to the Propane stove that spends more time burning daily making coffee, cooking bacon, frying eggs and all things keeping us fed and sometimes lit just to take the chill out.
Those heaters burn so infrequently that when I install mine my only concern will be just making sure that nothing gets too close to the unit but venting will definitely not be a concern.
Well ShagNasty you get the "So's your old lady" award on this one. Luck has a hand in the survival of each of us--I just like tipping the scales to the positive when I can.
Jack