installing a calorifier - need a new impeller?

[Modulation]

Snowleopard gave me some info a few months back on how to get domestic hot water even from my raw water cooled Yanmar 2gm20 engine. I'm well advanced with the installation and have already installed the tank and immersion heater - all works fine. Isn't on-tap hot water lovely?
If I can get away over the Xmas period I intend to do the connections between the engine cooling circuit and the calorifier heating coil. My niggling worry is if I need to beef up the engine water pump impeller. Because the "circuit" will be about 3 times longer than now will the existing impeller blades be strong enough? Or are they over-engineered and all will be ok?

 

[david_bagshaw]

all should be ok, unless you are restricting the flow heavly in some manner.

 

[snowleopard]

glad to hear it worked. the issue with the water pump isn't the length of pipe but the extra height to the top of the circuit. this needs some extra pressure initially but once the pipe is full the syphon effect will bring the required pressure down again.

just a note of caution - if you had an anti-syphon valve to start with, have you re-installed it at the highest point in the circuit? i'd hate to think i was instrumental in you getting a hydraulic lock!

 

[pappaecho]

If the "circuit" is closed then the pump will be sucking as well as pumping, like a central heating pump.. and in that instance 3 times the pipe length will not be a problem. If the system is open and not a circuit then you may be right about needing a bigger pump.... but I would try the system as is, and as long as the engine water cooling temperature stays the same, all you are doing is reclaiming the heat, before returning the raw water to the sea.

In that instance you will get a YOGI BLAIR <font color="yellow"> </font> badge for preventing global warming

 

[Anthony]

Hi,

I am grateful to Snowleopard who also shared the info with me /forums/images/graemlins/grin.gif, but I have yet to try it on my raw watrer 3gm30.

Please do let us know how well it all works when heating from the engine rather than the immersion.

Also where did u get your calorifier from? I was looking at the ones from ASAP supplies.

Thanks

Anthony

 

[GeorgeTina]

Hi
This is a request to Snowleopard. I too have a 2gm20 raw water cooled and would ike the information on how to connect to a calorifier. Can you help ?