Custom calorifier + Webasto Thermotop

[Blizz]

Hello,

I wanted to share my custom hot water system although I haven't invented anything new I think it could be interesting for someone.

I built a custom calorifier. Why custom if there many ones one the market? Basically because I could not fit the market ones where I wanted. My van is a L2H2 (130" MR) FWD wich means it has 10cm (4") more head space inside because floor is lower than RWD/AWD versions.

I started ordering a custom made SS tank with the fittings I needed. A big 1" thread for an electric resistor, two 1/2" more for the inlet/outlet and two small ones for drain/temp sensors.

Ordered with one of the ends unwelded.







Then had a pipe bending company build a coil made of 16mm SS. Welded some tabs to rest against tank walls.





With the idea of taking profit of my solar surplus I installed a 12V 200W resistance. It's slow but quite cheap so I can put a bigger one if I want.



Welded the cap and the coil pipes toghether



Installed some fittings on the coil's ends





As my van is still under warranty I prefer to avoid teeing the engine coolant's system (But it's the v2 idea) so i bought a flashed OEM BMW Webasto Thermotop from salvage yard and tried the system outside, redneck style





After the test which was good, I bought some chimney pipe and end caps to develop the tank outer cover



Cut it to size



Put the water tank inside and let's do a cake. Used insulation PU foam



After curing I cut the excess



Cut some holes on the caps



Finished product



(Continues)

[Blizz]

I used a long copper pipe for the tank cold water inlet to be far from the hot water outlet.



Installed a thermostat mixing valve and pressure relief with check valve too



Located the place for the water pipes to go in and out of the van



All my van's water system is done with PERT-AL-PERT pipe and press fittings, made all that was possible to do out



That's the space I designed the calorifier to go, did four holes and installed rivnuts



Phew! All fits and nothing sticks out more than the diesel tank



Before installing the valves and isolating the hoses



If possible, I always like to prepare my wiring outside. This is the Thermotop power supply, starting signal and temp sensor wiring



Installed a Y on the aux fuel port (I already had an Autoterm Planar 2D heater installed on it)







Tried to route all the wiring and pipes the best I could



Crossed to the passenger side over the heat shield parallel to an OEM wiring loom







(Continues)

[Blizz]

Designed a support plate and got it laser cut



Bolted the plate to the Thermotop and the set to the van body



Intake and exhaust where temporary, those are the OEM BMW ones cut to fit



Designed a small protection plate to avoid road splash





After some paint and installed



Made a temp support for the expansion tank



The pipes coming/going to the calorifier are under the kitchen's sink



Now I'm using the system completely independent to the engine cooland system. Thermotop takes 10 minutes to rise my 15l hot water tank to shower ready temperature. I plan to connect it to engine's cooling circuit in a future but I'll wait (Van it's still under warranty)

I'm super happy with the system. I installed an intake silencer and still need to installe an exhaust one altought the noise the Thermotop makes is more a "plane" or turbine sound rather than combustion noise.

Hope you like it!

Cheers,

David

[Altransit]

Nice work

[johnporter11]

I see you've used extruded aluminium also....

[Blizz]

I see you've used extruded aluminium also....

Yes, and I love it.

Not cheap but the finish is so good and sturdy...

Cheers,

David

[johnporter11]

45.JPG

Snap!