Webasto Thermo Top To Heat Exchanger

[bullracing]

I am converting my shuttle to a camper.
I will have no need for the rear heater or roof vents so I was going to whip the motor and rear rad out etc.
I do however have a plate heat exchanger which I brought for a Veg conversion years ago which never happened.
My question here is, could I use this alongside the Webasto to heat water for a shower?

The heat exchanger is similar to this one. similar in look. I will have to get mine and look in more detail at it. To be clear I am not expecting to be having a power shower, simply a warm/hot shower in the middle of no where when I have had a day out on the quad.

LN569500010009 | Liquid Heat Exchanger, 214.5 x 80.7 x 24.1mm | RS Components

 

[DXX]

I thought a Thermotop supplied hot water? If so I don't see the need for an addition heat exchanger.
Without specification or any calculations it's fairly safe to assume that the plate heat exchanger shown is too small for a single pass shower system. You would probably need a storage cylinder and circulation pump linked to the small heat exchanger.
There are probably simpler ways to get a hot shower.
Approx 12L of water is plenty for a shower, heat 6L in a pot on a gas burner or hob, add a further 6L of cold to get temp right and use a 12v remote switched Whale pump with a shower head attached.
If worried about scaring the public use a toilet tent, Khyam do an ok one.

 

[bullracing]

Yes I get boiling water is fairly easy but it's not on tap so to speak.
The heat exchanger I have warms veg using engine coolant so is the same principle but I totally get where your coming from in terms of may need more passes.
The termo top only heats the coolant in a closed system so I was planning on just putting the heat exchanger in place of the big ass rear rad and fan motor currently installed.
I will find out what heat exchanger I have and the spec on the thermo top to see if I can maybe slow flow down or even up the heat exchanger. That will be easier then lighting a fire, getting the stove on, heating a kettle full of water and then mixing with cold to then use a small 12v shower, not ideal when your soaked, covered in mud and it's raining type of thing. I do have one of the 12v bucket showers and its not half bad but it's a 3 min quick wash for about 15mins prep.

 

[oldiebut goodie]

I thought a Thermotop supplied hot water? If so I don't see the need for an addition heat exchanger.

You are thinking of a Dual Top no doubt, that is for engine and hot water supply.

 

[bullracing]

I have removed the 2nd heat exchanger and kept the rad in place.
I will either run it through the heat exchanger as I mentioned above. It shows on a fair few motorhome places this is how it is designed rather then going directly through the webasto. see diagram.
I will probably upgrade my heat exchanger though to one like this. They say it delivers between 30-42C at the taps without passes which is perfect for a shower on demand. I will however have to think about how I activate the webasto if I keep it connected to the van engine.


Or can anyone help me with trying to find the part that will blank the webasto from the engine so I can run it as a seperate system just for hot water? I am not sure if it will be a different hose or some sort of joiner, anyone able to assist on what and where I should be looking or a part number would be fantastic? I only have the hot water 2nd heat exchanger. I do not have AC in the rear which is handy. This way I will seperate the heater altogether and run it just to heat the water.

 

[bullracing]

I have ordered a mixing valve kit, 30 plate heat exchanger and a insulated jacket. Similar to the webasto one but for less then half the cost and the plate exchanger being slightly more efficient within the same size.

 

[HotandCold]

If you isolate the Thermotop from the engine cooling system, you will need to fit a header tank to allow for expansion and to self bleed the air from your hot water system. I have a hot water system similar to what you propose except that mine has a calorifier which contains the heat exchanger and stores 10 litres of hot water. My system is connected to the engine as well as the eberspacher hydronic heater (same as the thermotop) so water is heated anytime the engine is running. I have put some pictures on my build thread.

 

[bullracing]

Yes I did spot I would need an expansion tank and that would be a paint to setup seperately. I will not have room for a calorifier although that is the best way to do it especially having the stored water.

I am awaiting for the heat exchanger and then I can start getting it setup, once the hardware is in place I can then move on to how I get the webasto to come on and run. I dont really want to have to run the engine and it would be nice to isolate the engine so I am not heating that when it does not need it. I have not had a chance to look at the circuit diagrams yet, I will get lost in that when I have the main bits in place.

 

[bullracing]

I am a little bit further along now.
Have the heat exchanger, an insulating jacket and a mixer valve.

 

[bullracing]

 

[HotandCold]

If you leave the engine connected, you can use engine heat to heat the water (after a run for example) and you could fit a second circulating pump in series with the Thermotop to use the stored heat in the engine to heat the heat exchanger.

 

[gmcphoto]

View attachment 53931 View attachment 53932 View attachment 53933 View attachment 53934

How did this turn out? Thinking of a similar setup on my recent purchase