Flat Plate Heat Exchanger Questions

[Jeffrey]

The pump that Greg provided me works real well, and you have lots of hot water for an hour or more after the engine is turned off. Easy to install. I hate running the engine just for hot water, and never do it.

[daveb]

Great heads up on the heater hose Greg. Loss of coolant can lead to an expensive tow out of the field. I'll be looking at your silicon hose.

[Abitibi]

2nd revival of this good thread.

In post 6 or so, Steve (BACKRDS) nailed pretty good what I'm looking for but didn't really get an answer.

I'm also installing an Espar Hydronic and need to know how the engine coolant loop works to properly plumb in the Espar.

Where on the engine do I tap to get the coolant to feed the Espar and where on the engine or which hose should I tap in the return?

Can it be affected by the front heater control? ie. if set on cold will it cut the flow to the back as well?

Thanks
Mr. D

His post:
Can someone describe or provide a line drawing about the hose and pump arrangement of a Espar hydronic system, flat plate heat exchanger and the engine coolant loop. Are there extra pumps or check valves? I've been using the espar and flat plate, and after I added a tempering valve we are now happy with the setup. We also take showers with a warm engine (espar off). However without circulation through the warm engine, the shower water gets cooler and cooler. So I want to add an auxiliary 12 volt pump to circulate coolant through the warm engine and the flat plate heat exchanger. One option is to put the aux pump in series, but it will result in some degree of restriction if it is not "on" when the espar is also on, with the espar pump running. I don't know if the restriction will be enough to be a problem for the espar if the aux pump is not on. Any experience here?

What produces the flow from the engine to the flat plate heat exchanger when just driving down the road? Is there a split somewhere downstream of the engine water pump where part of the flow goes to the radiator and part goes to the loop with the espar and flat plate heat exchanger? If so, does the partial stream of flow to the radiator mean less effective cooling for the engine?

So, how does the SMB supplied Espar and flat plate heat exchanger connect with the engine coolant loop?

[BACKRDS]

Let me also clarify my earlier set of questions about wanting to pull heat from the engine while the engine is off and without the espar firing up. 1) I understand this could be done either by hacking the espar controls to be able to toggle the pump on (without the burner on), or by 2) adding an aux pump in the SMB installed coolant loop. I thought I read somewhere that SMB plumbed (tee'd on both sides) the espar/flat plate loop into the feed and return of the heater core, which would feed hot coolant to the flat plate if the engine was running. However, when the engine is off, wouldn't an extra aux pump on the espar loop really force the coolant through the heater core (easiest path) and not through the hot engine itself? Seems like a check valve might be needed?

Thx,
Steve

[daveb]

http://www.badgertrek.com/sportsmobile/appliances.shtml