[P @ F]

My water goes in at the point the coils start, up towards the loose coil , this is the burner end , then it comes out through the long straight away from the burner , that is the downside to being able to slide the whole coil out, but it does do away with internal connections .
Gonna weigh this lot in with old alloys and batteries soon !

[a900]

Did the copper wrap around the outside work at all?

[P @ F]

Did the copper wrap around the outside work at all?

I don’t think it made a difference to be honest  , it only really made a difference when the feed water was quite warm , when cold it seemed to zapp heat from the chrome pipe to the point that the inner coil suffered  as a result, don’t forget though that that was on Mk1 where the inner coil was hard up against the inside of the chrome pipe

[a900]

I’m going to change my set up. So I have water out the tank through the EGR cooler into the pump. Then Through the exchanger then either to the hose reel or a pressure relief valve into the tank.

That way I will always be able to keep the coldest water over the egr cooler to extract the most wasted exhaust heat. This should give me a little warmer inlet temps for the main heat exchanger. Hopefully this is the simplest way to increase the efficiency a little.

Is your pump working hard to overcome the 6 bar relief valve? I’ve just order a 2 bar. Hope that’s enough

[Perfect Windows]

Here's a nice, daft question (and it cuts back to earlier points in the thread before trying to get "waste" heat out of the exhaust). Rather than using a heat exchanger to move heat from a closed loop into the pure, has anyone tried just running pure directly through the heater and seeing if it becomes contaminated in any way?

For information, I've not been following every word of the thread so this may (1) already have been covered (2) not relate to what's being done now (3) be a really stupid question for a reason I don't even know exists.

Vin

[P @ F]

I’m going to change my set up. So I have water out the tank through the EGR cooler into the pump. Then Through the exchanger then either to the hose reel or a pressure relief valve into the tank.

That way I will always be able to keep the coldest water over the egr cooler to extract the most wasted exhaust heat. This should give me a little warmer inlet temps for the main heat exchanger. Hopefully this is the simplest way to increase the efficiency a little.

Is your pump working hard to overcome the 6 bar relief valve? I’ve just order a 2 bar. Hope that’s enough

I dont have a 6 bar PRV , its a 3 bar ! , So about 45 PSI + 20% , so 55 PSI release , its the standard valve that plumbers use day to day , I can get a 2 bar on Ebay for £10 .
That should release at 35 PSI tops , back when I had a pressure gauge within the  system I found that running as normal with Univalve open was about 25 PSI , so 35 blow off should be perfect !
The 3 bar does not really labour the pump as it is but 2 would be a better choice I think .

[P @ F]

Here's a nice, daft question (and it cuts back to earlier points in the thread before trying to get "waste" heat out of the exhaust). Rather than using a heat exchanger to move heat from a closed loop into the pure, has anyone tried just running pure directly through the heater and seeing if it becomes contaminated in any way?

For information, I've not been following every word of the thread so this may (1) already have been covered (2) not relate to what's being done now (3) be a really stupid question for a reason I don't even know exists.

Vin

 

That is what I am doing Vin !
Tank-Pump-DI-Copper coil inside exhaust-Hose-Window .
When I shut pole off the hot water goes back to tank and back through above again .

[P @ F]

No secondary water cicuit , extra pumps , batteries , split chargers .
Just an 85 amp Numax MF linked to alternator and solar charge system .

[Perfect Windows]

That is what I am doing Vin !
Tank-Pump-DI-Copper coil inside exhaust-Hose-Window .
When I shut pole off the hot water goes back to tank and back through above again .

Sorry, as I mentioned, I've not read every word of the thread.

The setup I thought might be effective was something along the lines of those people who have an immersion, so heating the tank of water but with a Webasto rather than the dodginess of a self-installed immersion heater.

Your work on recovering the heat from the exhaust is a crucially important addition, in my opinion.  It seems to me that in an ideal world you'd want the exhaust to come out at ambient temperature for maximum efficiency.  It really surprises me that no-one offers this as a built option.

Vin

[a900]

https://youtu.be/IjDDlI_42a4 Might be useful to making that set up work perfectly

[P @ F]

That is what I am doing Vin !
Tank-Pump-DI-Copper coil inside exhaust-Hose-Window .
When I shut pole off the hot water goes back to tank and back through above again .

Sorry, as I mentioned, I've not read every word of the thread.

The setup I thought might be effective was something along the lines of those people who have an immersion, so heating the tank of water but with a Webasto rather than the dodginess of a self-installed immersion heater.

Your work on recovering the heat from the exhaust is a crucially important addition, in my opinion.  It seems to me that in an ideal world you'd want the exhaust to come out at ambient temperature for maximum efficiency.  It really surprises me that no-one offers this as a built option.

Vin

If I had a bit of wedge to build this thing into an off the shelf item I would believe me !

[P @ F]

https://youtu.be/IjDDlI_42a4 Might be useful to making that set up work perfectly

Best link since sliced bread that !
I saw his first review vid , it was one of the vids that inspired me to build my machine.
But a quick look at the latest here has just given me 60 degree water on demand from cold tank !
a900  what a find matey , cheers 

Good job I ordered that heat wrap and prv you linked the other day as my chrome pipe has just made my infrared thermometer obsolete by getting over 650 Celsius !

[Perfect Windows]

Your work on recovering the heat from the exhaust is a crucially important addition, in my opinion.  It seems to me that in an ideal world you'd want the exhaust to come out at ambient temperature for maximum efficiency.  It really surprises me that no-one offers this as a built option.

Vin

If I had a bit of wedge to build this thing into an off the shelf item I would believe me !

I just found something on a narrowboat forum where they pointed out my theory above is incorrect.  You can't cool the exhaust too much as it will cause water vapour in the exhaust (around 12% of the exhaust volume) to condense into liquid in the exhaust if its temperature is too low.

Getting the right amount of heat however, is free energy.

Vin

[a900]

https://youtu.be/IjDDlI_42a4 Might be useful to making that set up work perfectly

Best link since sliced bread that !
I saw his first review vid , it was one of the vids that inspired me to build my machine.
But a quick look at the latest here has just given me 60 degree water on demand from cold tank !
a900  what a find matey , cheers 

Good job I ordered that heat wrap and prv you linked the other day as my chrome pipe has just made my infrared thermometer obsolete by getting over 650 Celsius !

Now this is getting impressive. 60c on demand.

I’ve replumbed my water heater to preheat the water from the egr cooler. And finding I’ve made it a lot more efficient. The pump speed that used to allow the heater to idle isn’t enough. It needs a lot more water flow. Not able to do anymore testing as the circulation pump has broken and waiting for a replacement.

[a900]

Your work on recovering the heat from the exhaust is a crucially important addition, in my opinion.  It seems to me that in an ideal world you'd want the exhaust to come out at ambient temperature for maximum efficiency.  It really surprises me that no-one offers this as a built option.

Vin

If I had a bit of wedge to build this thing into an off the shelf item I would believe me !

I just found something on a narrowboat forum where they pointed out my theory above is incorrect.  You can't cool the exhaust too much as it will cause water vapour in the exhaust (around 12% of the exhaust volume) to condense into liquid in the exhaust if its temperature is too low.

Getting the right amount of heat however, is free energy.

Vin

This is something I am finding now. Got my webasto 90 with an egr cooler on the exhaust. Water runs through the EGR cooler into the pump and through the heat exchanger to the reel.

The exhaust is now warm. Can hold your hand in front of the outlet and it’s a pleasent warm temp. Noticed I’m getting a lot of condensation in the tail part of the exhaust now. Will have to see how it effects the exhaust over time. Will it mix with soot and clog up. Who knows.

Will probably cut a small hole in the lowest part of your exhaust so condensate can drip out.

But success in efficiency. Before 12 on my controller kept the boiler from shutting off at idle. Now it needs 30 to stay on idle.

[P @ F]

I have just fitted the exhaust wrap and 2 bar prv , not run the heater yet but will know tomorrow if it makes a difference, as for the prv it would seem 2 bar is the one to have , when pole shut off it only 3 seconds until it opens up , and the pump then draws exactly the same power as it does with system running as normal

[a900]

I have just fitted the exhaust wrap and 2 bar prv , not run the heater yet but will know tomorrow if it makes a difference, as for the prv it would seem 2 bar is the one to have , when pole shut off it only 3 seconds until it opens up , and the pump then draws exactly the same power as it does with system running as normal

Ace. Keep us updated

[dazmond]

hows the heater running rich?

[P @ F]

hows the heater running rich?

Absolutely bang on Daz , now that I have found out how to access the burner settings on the LCD control unit I can adjust diesel injection and air intake to give me anywhere between 35 to 60 degrees on demand from a cold tank.
And all this is using just 5 amps an hour and between 400 and 600 ml of diesel per hour !
I am just in the process of refitting the van again so I can use the 10L tank supplied with the heater as opposed to topping up a 5L can every day .
I am also doing away with the steel frame on my hose reel and making a more compact one , have not gone back to the drill yet though 😁

[P @ F]

I have just fitted the exhaust wrap and 2 bar prv , not run the heater yet but will know tomorrow if it makes a difference, as for the prv it would seem 2 bar is the one to have , when pole shut off it only 3 seconds until it opens up , and the pump then draws exactly the same power as it does with system running as normal

Ace. Keep us updated

As I said, the 2 bar PRV is the one for me .
As for the heat wrap , it does not seem to have made much difference to temps, but it is serving a purpose in keeping the surface of the chrome pipe down, my fear was that on pull out the reel would maybe over spool and the hose would land on the hot pipe, not an issue now though.
You can tell it is cheap stuff though as when first fired up it smokes like mad and then changes colour to white , so I could have picked any old colour really 😆