Into Hot Water Again!

July 12, 2011

Into hot water again. Yes, the luxury of having on-demand hot water in The Tortuga Expedition Camper was addictive. Our Seaward marine hot water heater took heat from the engine coolant or our Espar D5 Hydronic coolant heater. The problem was, we were carrying around 6 gallons of water that could not be used unless we pumped cold water into the tank to push the hot water out. The solution was to install a FlatPlate double wall brazed plate heat exchanger. This little piece of 21st-century technology, about the size of a loaf of bread, will give us endless hot water as long as the engine or the Espar D5 Hydronic is pumping coolant through its plates. The diesel-powered Espar D5 is even smaller than the FlatPlate, and can also preheat the engine on cold mornings, thanks to a system of valves and distribution manifolds designed for us by Espar. More on this after we’ve taken a hot shower.


Espar D5 Hydronic

Espar Manifolds

2 Responses to “Into Hot Water Again!”

  1. Amazing space saving device!!
    In the last picture there is a aluminum box witch the espar feed (of output) water, is that your expansion tank?
    Or with such setup you don’t need that either?

    Are you using a radiator for heat exchange to heat the living space also?
    Thanks for the clarification


  2. Samuel,

    Our Espar D5 Hydronic heater heats coolant from the engine cooling system. The two stainless steel boxes are transfer manifolds. Different valves allow the D5 to heat the Hunter radiator in the camper, the Flatplate hot water heater and preheat the engine on cold mornings. The D5 just heats coolant and pumps it to what ever we want to heat, engine, Flatplate, Hunter, or all three at the same time. If the engine is already hot from driving, or while driving, the valves and transfer manifolds can be set so the Hunter radiator and Flatplate hot water heater are working as long as the engine’s coolant is being pumped through the system by the engine. On a normal morning in camp, with the engine off and cold, the Espar Aritronic heater is used as the primary heater for the camper. By setting the valves for the D5 to pump heated coolant, up to 187°F, through the Flatplate, we have hot water in about three minutes. A temperature control valve in line after the Flatplate keeps the water at a safe 120°F.


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