Plumbing Espar Hydronic D5

[B350]

Looking for a little help and input on simple Espar Hydronic D5 plumbing to provide hot water for a sink and exterior shower only.

My questions:
1. Is it necessary to put a hot water tank into the system since the Espar D5 is able to heat water as it passes through the heater?
2. The Espar has a 1gpm pump rate while the Shurflo pump has a 2.3gpm pump rate. Will this end up pushing water through the Espar too quickly for it to heat the water?
3. Being the Espar does have a pump that circulates water when it is turned on would it be necessary to put in a water bypass circuit so water can actually circulate and get heated?
4. Will the pressure coming out of the Espar and hot water tank be enough for the shower and sink? Or, would a second pump be needed for the hot water?

This is the plumbing diagram I put together. No drains or other details are included for simplicity. Appreciate any help!

 

[loonwheeler]

The flow rate of the Espar D5 is definitely not enough for a sink or shower. Consider integrating another tank and a dedicated pump for both the shower and the sink.

Also keep in mind the D5 works in a circuit (loop), not one way to the hot water tank. It has an internal thermostat and when the water in the loop drop below a set point, the heater automatically fires back up and keeps the temperature as near the set point as possible. The diagram would be more accurate if you had a loop between the hot water tank and the D5. Then, run the cold water line from the accumulator into the hot water tank on the inlet side and get hot water out.

 

[S2DM]

You absolutely need to have two separate loops. The espar is not designed to heat water directly, in fact it is not rated to run water at all, it needs to be a glycol or similar solution. That solution is heated and then comes into contact with the water you would like to heat through a heat exchanger like a flat plate.

In short, you need the espar, an expansion tank in line, and then heat exchange elements. That could be a copper coil in a water tank or a radiator type arrangement with a fan.

You can do something similar to what you are after with a flat plate heat exchanger to give on demand hot water. Check out Jeeps flat bed and composite panel build thread. But it still requires two loops in order to achieve it.

 

[loonwheeler]

The espar is not designed to heat water directly, in fact it is not rated to run water at all, it needs to be a glycol or similar solution. That solution is heated and then comes into contact with the water you would like to heat through a heat exchanger like a flat plate.

You are right - the Espar circuit does need a solution like glycol to prevent corrosion of the internal components. Sorry - I missed that detail in my previous post. All other items you mentioned are spot on.

 

[B350]

Thank for the insight guys. Taking this into consideration I revised the setup so that the Espar runs a smalled closed loop through the heat exchanger with coolant.
Does anybody see any flaw/s in this setup?

 

[grizzlyj]

Hi.
.
The water filter will reduce flow a little, so hot vs cold at the sink might be too imbalanced?
.
Maybe have hot, cold and a separate drinking tap?
.
The Espar circuit will get air in it over time, so a bleed point at all high spots makes life a bit easier, and a header tank is supposed to be needed too. My last set up had neither and once air was in it was a pain to get out again!

 

[javajoe79]

It's also pretty easy to tie the Espar into your engines cooling system so you also create hot water while you drive

 

[fluffyprinceton]

"Thank for the insight guys. Taking this into consideration I revised the setup so that the Espar runs a smalled closed loop through the heat exchanger with coolant.
Does anybody see any flaw/s in this setup?"
That would work & it's the simplest arrangement but consider other uses for all that heat created like cabin heating and heating the engine before starting in freezing temps.Moe

grizzlyj & Javajoe have some excellent advice -
"The Espar circuit will get air in it over time, so a bleed point at all high spots makes life a bit easier, and a header tank is supposed to be needed too. My last set up had neither and once air was in it was a pain to get out again!"

"It's also pretty easy to tie the Espar into your engines cooling system so you also create hot water while you drive"

 

[dwh]

I think all those hydronic units have a minimum amount of required coolant for the glycol loop in order to prevent short cycling.

 

[Abitibi]

This is how I started building mine. I made manifolds so that 3 heating systems are possible.

*engine and wvo pre-heat
*hot water
*interior heat

My heater is the larger unit but all the same. Anyway here's a picture to "explain it"...

I circled in red my breather valves, one per circuit which I believe is a must. I'm using mine to pre-heat my veggie system but most won't have that...

I also put valves on each circuit so that I can bypass a circuit when not needed. Who needs to have hot coolant run through your bus heater in the middle of summer, right? I just unscrew and remove the handles (i keep one in my toolbox) so they don't get opened by mistake or catch up on branches...

Cheers
David

Sent from my SM-G900W8 using Tapatalk

 

[B350]

Thanks again for more good info on this Espar setup. I am really trying to keep it as simple as possible and use it for water heating only. I'll have another unit for air/cabin heating and I'm not worried about preheating the van's engine. It starts easy enough at -10F here in MN and doesn't get used in the dead of winter.

Taking into consideration the need to bleed air from the coolant/gylcol loop and increasing the loop's capacity, would an over flow tank like the one pictured work? It has approximately a 1L capacity, an inlet and outlet, and the ability to bleed air and fill coolant at the cap. Would this work?



New plumbing setup would look like this then.

 

[javajoe79]

I think you would just want the expansion tank to T into the main line. The lines on the one pictured are too small to flow what the espar flows. Also those tanks aren't sealed, they are vented as it's meant to hold the coolant from a radiator as it warms up and expands and then allow it to be sucked back in to the radiator as it cools. I would think that you want a pressurized system just like a vehicle's cooling system. One with a pressure cap and an expansion tank.

 

[fluffyprinceton]

dwh - "I think all those hydronic units have a minimum amount of required coolant for the glycol loop in order to prevent short cycling." Correct - it's at least several gallons if I remember correctly. Do yourself a favor & log on to Espar's website and gain a better understanding of how these things need to be installed.Moe

https://www.eberspaecher-na.com/download-center/technical-manuals.html

 

[Pinnacle Campers]

Thanks again for more good info on this Espar setup. I am really trying to keep it as simple as possible and use it for water heating only. I'll have another unit for air/cabin heating and I'm not worried about preheating the van's engine. It starts easy enough at -10F here in MN and doesn't get used in the dead of winter.

Taking into consideration the need to bleed air from the coolant/gylcol loop and increasing the loop's capacity, would an over flow tank like the one pictured work? It has approximately a 1L capacity, an inlet and outlet, and the ability to bleed air and fill coolant at the cap. Would this worK?

New plumbing setup would look like this then.

You say you want to keep it simple but you are adding complexity and duplicating parts that you already have.

If you have a rear HVAC, installing the unit into the system couldn't be simpler.
I tapped into the 3/4" rubber heater hose headed for the rear HVAC right behind the doghouse. Ran it to the espar and from the espar back to the point headed to the rear HVAC. I used the barbed couplers and rubber hose that came with the kit.
I have run the system since last fall setting the timer for just before I leave in the morning. It's nice to have the coolant loop preheated and dash heat (and defroster!) right away.
I plan to tap into the coolant loop again inside the cabin where there will be a plate type heat exchanger for hot water heating.
In other words, don't be afraid to tap into the existing coolant loop and use the product how it was designed. ✌🏼

 

[javajoe79]

You say you want to keep it simple but you are adding complexity and duplicating parts that you already have.

If you have a rear HVAC, installing the unit into the system couldn't be simpler.
I tapped into the 3/4" rubber heater hose headed for the rear HVAC right behind the doghouse. Ran it to the espar and from the espar back to the point headed to the rear HVAC. I used the barbed couplers and rubber hose that came with the kit.
I have run the system since last fall setting the timer for just before I leave in the morning. It's nice to have the coolant loop preheated and dash heat (and defroster!) right away.
I plan to tap into the coolant loop again inside the cabin where there will be a plate type heat exchanger for hot water heating.
In other words, don't be afraid to tap into the existing coolant loop and use the product how it was designed. ✌🏼

My thoughts as well. Doing so will actually simplify your setup. No need for an expansion tank at that point. Probably won't need a bleed point if it's all mounted low but a bleeder is really simple if needed