Rear Heater - Night heater conversion

[cptsideways]

Ahah - I have it tee'd into the blue 61-214 pipe, so its circulating the wrong way as I thought, well actually the right way but via the header tank & everything else etc, , mighty effective going that way haha

Well swapping it around the other way is no goer, it appears this is not the way the heater system works, back to the first method I think.

Just to clarify: It appears not to work pumping into the block first - the flow route suggested by the diagram.

[g8dhe]

Are you not disconnecting the heater matrix then ? But rather pumping heated water thru the entire system ?

[g8dhe]

Would you not be better taking the feed to your heater from the engine side of 61-213 and then feeding your heated water back in at the same point but going to the heater matrices? That way engine pumped coolant would flow thru your heater in the normal driving mode, but then when you stop and fire up your heater the hottest coolant would go straight to the heating matrices directly ?

[cptsideways]

Would you not be better taking the feed to your heater from the engine side of 61-213 and then feeding your heated water back in at the same point but going to the heater matrices? That way engine pumped coolant would flow thru your heater in the normal driving mode, but then when you stop and fire up your heater the hottest coolant would go straight to the heating matrices directly ?

Yes!

This is the next plan, involves some longer pipework but now having worked out whats actually going on this should work well.

Any engine heat will reduce heater usage - I can turn it on, it automatically circulates the water & will turn the burner on when water temps drop below 60deg. Hopefully I can get it to work though there is always the issue of path of least resistance.

Just ordered some new T pieces & pipe

[mikeonb4c]

Would you not be better taking the feed to your heater from the engine side of 61-213 and then feeding your heated water back in at the same point but going to the heater matrices? That way engine pumped coolant would flow thru your heater in the normal driving mode, but then when you stop and fire up your heater the hottest coolant would go straight to the heating matrices directly ?

Might this not miss a trick though. First, if the Webasto pump is able to pull coolant around the whole system, it will be able to take legacy heat from a hot engine and use it to good effect by passing it through the rear heater matrix. Then , when its thermostat tells it to light the burner, it will be able to invest heat back into the whole engine block so that it can in turn black-body / conduction radiate gently heat into the cab via the central engine cover area. Also, a small low capacity circuit is more likely to cause the system to 'hunt' as the volume of coolant requiring heating is much less and the thermal mass of the body to be heated is much less also, so that the thermostat may be forever switching the system on and off.

I'm no heating engineer though so the above really is just questions, not authoritative suggestions

[cptsideways]

UPDATE

I can confirm it works!! A bit too well if anything

Just back from 5 days skiing in the Vosges region of France, parked up at Altitude it got down to -10 a couple of nights & I still had to leave a window or two open to let the heat out

Think a thermostat of some sort would be a good idea in the long run. It's runnning full loop so heating the engine & all the works, a full exterior front window cover that overlaps the bonnet top lip would mean getaways first thing with no demisting. I have interior blinds which are frankly rubbish putting them on the outside worked 10 times better.

Fuel use was hardly noticeable compared to the Bongo's general thirst @ about 11-12L/100km which is frankly awful compared to my two other cars a Lupo 3L & Honda Insight lol.

[g8dhe]

Did you move the heater path to the outlet from the engine/inlet to heating matrix ? Or is it still on the nearside ?

[cptsideways]

The heater pump "sucks in" from the left hand side small pipe by the alternator into the heater & out via a pipe that feeds & tees into to the rear heater matrix "input"

Its using the original header tank which is handy, I'm using an original Rover 75 heater output pipe which has a handy bleed valve on top which is just in the right place for this job.

If you wanted to just pipe to the heater that would work fine but you would need a remote header tank for the system.

[mikeonb4c]

UPDATE

I can confirm it works!! A bit too well if anything

Just back from 5 days skiing in the Vosges region of France, parked up at Altitude it got down to -10 a couple of nights & I still had to leave a window or two open to let the heat out

Think a thermostat of some sort would be a good idea in the long run. It's runnning full loop so heating the engine & all the works, a full exterior front window cover that overlaps the bonnet top lip would mean getaways first thing with no demisting. I have interior blinds which are frankly rubbish putting them on the outside worked 10 times better.

Fuel use was hardly noticeable compared to the Bongo's general thirst @ about 11-12L/100km which is frankly awful compared to my two other cars a Lupo 3L & Honda Insight lol.

This is SUCH a good idea. I recall raising this idea on BF years back and getting blank responses so it cheers me no end to hear it's been done. Potential advantages off this are (in my view):

A better kind of heat, stabilised by heating a large thermal mass.
A healthier kind if heat if the radiant approach is used - blown dry hot air is not the best for breathing.
Potential for less noise in the night due to longer intervals between needing heater on once thermal mass is warmed.
Even g5entler heat better for driving off damp, keeping engine warmed etc.
Potential to heat water if suitable tank put in circuit (with heat exchanger)

But this could all be bunk so feel free to lay into my logic.

[cptsideways]

UPDATE

I can confirm it works!! A bit too well if anything

Just back from 5 days skiing in the Vosges region of France, parked up at Altitude it got down to -10 a couple of nights & I still had to leave a window or two open to let the heat out

Think a thermostat of some sort would be a good idea in the long run. It's runnning full loop so heating the engine & all the works, a full exterior front window cover that overlaps the bonnet top lip would mean getaways first thing with no demisting. I have interior blinds which are frankly rubbish putting them on the outside worked 10 times better.

Fuel use was hardly noticeable compared to the Bongo's general thirst @ about 11-12L/100km which is frankly awful compared to my two other cars a Lupo 3L & Honda Insight lol.

This is SUCH a good idea. I recall raising this idea on BF years back and getting blank responses so it cheers me no end to hear it's been done. Potential advantages off this are (in my view):

A better kind of heat, stabilised by heating a large thermal mass.
A healthier kind if heat if the radiant approach is used - blown dry hot air is not the best for breathing.
Potential for less noise in the night due to longer intervals between needing heater on once thermal mass is warmed.
Even g5entler heat better for driving off damp, keeping engine warmed etc.
Potential to heat water if suitable tank put in circuit (with heat exchanger)

But this could all be bunk so feel free to lay into my logic.

All spot on I'd say, I'm going to rubber mount the unit as its just audible on the high output & starting up (more internal fan noise than anything) but still pretty quiet. The Bongo blower is fine & barely audible, being be able to adjust it from air below, above or both is great. When sleeping I set it on the lower setting so you get a heated bed! Works brill, if up & about then sticking it on the upper vents warms the whole van up nicely & quickly too. It really is rather good & I can get up when -10 outside & get on the road to skiing straight away with a warm engine.

Best bit is I have storage by the lower blower so you get heated ski boots

[mikeonb4c]

You'd be doing us all a huge favour by producing a fact sheet with photos that could live in the member's area in the factsheets library. The centrally mounted engine of the Bongo is what makes your approach especially valuable.

Do you think there would be a way of incorporating a fresh water heater in the circuit, as that would be a very useful enhancement.

I can honestly say this is (for me) the most interesting Bongo modification i've ever read about on here. Congrats

[cptsideways]

I'll see what I can organise on that front

[mikeonb4c]

I'll see what I can organise on that front

Yayyyy:-) Gawd but i could be tempted to have a go at fitting something. What do you think about the possibility of hot fresh water? Could that work? Presumably something with heat exchanging coils/matrix would be needed?

Note to readers: Don't try this at home on an air cooled rear engined VW Type 2 folks

[cptsideways]

I'll see what I can organise on that front

Yayyyy:-) Gawd but i could be tempted to have a go at fitting something. What do you think about the possibility of hot fresh water? Could that work? Presumably something with heat exchanging coils/matrix would be needed?

Note to readers: Don't try this at home on an air cooled rear engined VW Type 2 folks

Hot water yes, but you'd need a calorfier I think they are called, a heat exchanger would work plumbed inline but only really if the system was up & running. The unit itself takes about 2mins to get going so I can't see it being good for direct (via heat exchanger) hot water as such. They run at about 65-75C water temps IIRC

[cptsideways]

Right done a full write up but pics are too large for some reason, can I email someone the blurb for a techy file