Coolant flow in 1HZ and Glind heat exchanger

Submitted: Tuesday, Apr 11, 2006 at 21:55
ThreadID: 32808 Views:6138 Replies:6 FollowUps:1
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A mate just installed a Glind shower in his 1HZ Troopie and when he compared his install to the one in my 100 series (1HZ), he reckons the flow through the heat exchanger is the wrong way round in mine. When I'm heating cold water, the water is never quite hot enough to shower in unless you slow the flow through the shower rose, so it got me thinking that it could be arse about. If the coolant flow comes from the drivers side of the block, then mine is installed correctly, but if it goes the other way, should I expect the shower to never be hot enough?

I've checked out the Glind site and it talks about installations in vehicles with heater taps in the heater hoses. Any ideas about 100's? Also, a valve is installed in the pipe between the engine and the heat exchanger, but shutting it off doesn't result in one side being hotter than the other and confirming which way the cooland flows. Any ideas anyone? and thanks in advance,

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Reply By: David from David and Justine Olsen's 4WD Tag-Along - Tuesday, Apr 11, 2006 at 22:07

Tuesday, Apr 11, 2006 at 22:07
I don't know the construction of the heat exchanger but it sounds like your si set up co-current and your mates is counter current. ie yours has the flow of cold water running in the same direction thru the heat exchanger as the hot water, and your mates is reverse. if so, this will account for a difference in performance.
AnswerID: 166552

Reply By: Tim_N - Wednesday, Apr 12, 2006 at 09:02

Wednesday, Apr 12, 2006 at 09:02
The coolant flow and the shower water flow MUST run in opposite directions and that is the way heat exchangers work in any application. To check if your coolant is running the right way, remove the coolant hose from the exchanger, the one right next to the shower outlet fitting. The coolant must be running from the hose into the exchanger to have correct direction of coolant flow.
Also with most 1HZ's, to get a constant flow of hot water, you should screw up the engine rpm to about 1200 rpm to get sufficient coolant flow to heat water, especially cold water. All diesels require more coolant flow than petrols and nearly all diesels benefit from the lift in engine rpm. Heat exchangers require a minimum of 6 l/min of coolanr flow in order to heat water sufficiently, some diesels at idle only pump through about 4 to 5 l/min, not enough, hence the increase in rpm to increase coolant flow and resultant heat.
The Troopie has a heater control valve and the 100 doesn't, but the coolant pipe on the back of the block on the passenger side of both is the feed line.
Another big area where heat is lost is when you may have an aftermarket turbo and water is tee'd off to the turbo. Some people put the heat exchangers in the line between the 2 tee's. What happens here is that the coolant flow after 1 tee is only about half as part of the coolant is diverted to the turbo and the other part runs along the main hose. This does nothing for either the shower or the turbo.
To do it properly, the heat exchanger must be plumbed into the coolant feed hose first and before it is tee'd off. This ensures the heat exchanger gets the full flow of coolant and the turbo gets its recommended amount of coolant. Otherwise both pieces of equipment will be compromised and not work to their fullest.
I hope this helps
AnswerID: 166610

Follow Up By: David from David and Justine Olsen's 4WD Tag-Along - Wednesday, Apr 12, 2006 at 20:26

Wednesday, Apr 12, 2006 at 20:26
Some older industrial heat exchangers are co-current flow. Inefficient I know but some are still configred that way.

Dave O
FollowupID: 421695

Reply By: Tim_N - Wednesday, Apr 12, 2006 at 15:21

Wednesday, Apr 12, 2006 at 15:21
Further to the above, if a heat exchanger is plumbed with the coolant and the shower water running in the same direction, you will get a blast of hot water for about 5 seconds and then it will run cold and even if you rev the guts out of the motor, you will only get very luke warm water. If yours is doing this, then it is plumbed in back to front and will never work. The efficiency of a heat exchanger is dropped by over half.
Simply flip the coolant hoses to opposite ends and hey presto it will wprk as it is meant to.
AnswerID: 166692

Reply By: atoyot - Wednesday, Apr 12, 2006 at 17:30

Wednesday, Apr 12, 2006 at 17:30

Thanks for that; very informative. I suspect that mine is plumbed wrong, as the cooland inlet on the H/E (with the arrow for directional flow) is connected to the pipe on the drivers side of the block. If this is correct, then I would actually have the pumped water flowing in the same direction as the coolant (heatant?).

It works OK if you restrict the flow and up the idle, and it works pretty well when I recirculate the water into a container for wating up water etc.

I'm not even sure if I need the valve on the inlet side of the H/E either, as it never really gets hot enought to have to restrict the coolant flow, but, then again, if it's all plumbed wrong, it wouldn't make much difference anyway,

thanks for you reply,

AnswerID: 166725

Reply By: Tim_N - Thursday, Apr 13, 2006 at 09:29

Thursday, Apr 13, 2006 at 09:29
Hi Andrew,
It sounds like yours is plumbed up the wrong way. With a 1HZ, you should be able to get a constant flow of hot water at full flow simply by increasing engine rpm to 1200 and if you reduce the flow at the shower rose, it will get very hot.
As the 100 series does not have a heater control valve, you can still use the hose on the drivers side but it must run out of the firewall, into the exchanger and run from the exchanger into the hose on the drivers side. To fix yours, simply swap the coolant hoses to the opposite ends.
You won't need a flow valve either as these are only used to slow coolant flow down if the shower is too hot at idle.
AnswerID: 166858

Reply By: Member - 'Lucy' - Thursday, Apr 13, 2006 at 14:40

Thursday, Apr 13, 2006 at 14:40

I have 1HZ Trooper with a shower in it and the sucker will 'boil you alive' if you are not carefull.

So I would suggest you definitely have something A' about in your set up.
AnswerID: 166891

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