Is there a max. height for Thermosyphon to work ?

[TheyCallMeDave]

If a solar collector is mounted on the ground and there is a horizontal (inclinded) piping run of 25' (each for supply and return) then a vertical run of 10' to the water heater tank....will the water still move ? Are there limits ?? Thanks

[AC_Hacker]

Originally Posted by TheyCallMeDave

If a solar collector is mounted on the ground and there is a horizontal (inclinded) piping run of 25' (each for supply and return) then a vertical run of 10' to the water heater tank....will the water still move ? Are there limits ?? Thanks

Dave,

I can't answer your question directly, but I was browsing through a very dated manual on steam heating, which didn't use circ pumps and did have to contend with most of the considerations you are facing. If you can't get answers directly to your questions, you might hunt up an old steam heating manual for clues on how to approach the problem.

-AC_Hacker

[Daox]

My best guess (and just a guess) is that it will work, however not well. That is a pretty long jog horizontally.

[TheyCallMeDave]

Probably steam and a full head of water have different movement characteristics . I suppose a small bronze pump will have to implemented but first ill see if it thermosyphons.

[Daox]

It would probably help to insulate the hot line to make sure that the water doesn't cool down over the long horizontal leg.

[GaryGary]

Hi,
This is a pretty interesting article on a thermosyphon system with long runs:
http://www.builditsolar.com/Projects...ater97_shw.pdf

It looks to me like it might work OK.
With any thermosyphon system, its important to have no places in the plumbing (even short sections) where the pipe gradient is adverse to the thermosyphon flow -- even a very short section or badly oriented fitting can stop the flow.

Some more articles/tests on thermosyphon systems: Solar Water Heating Projects and Plans


Gary

[TheyCallMeDave]

Originally Posted by GaryGary

Hi,
This is a pretty interesting article on a thermosyphon system with long runs:
http://www.builditsolar.com/Projects...ater97_shw.pdf

It looks to me like it might work OK.
With any thermosyphon system, its important to have no places in the plumbing (even short sections) where the pipe gradient is adverse to the thermosyphon flow -- even a very short section or badly oriented fitting can stop the flow.

Some more articles/tests on thermosyphon systems: Solar Water Heating Projects and Plans


Gary

Thanks for the sites. Ive got the system completely installed and elected to parallel the water heater ( using a bypass system of 3 valves ) and have the Collector water feed directly into the hot water supply line to the entire house ; this way, when i open a hot water faucet , line pressure forces the water out of the Collector . It is working exceptionally well ........ on a sunny 90 f. day after 5 hours the Collector water is up to 158 f. And on a 84 f. cloudy day where it rained much of the time, the Collector water still reached 110 f. --- certainly enough for a 5-10 min. shower. This is with the Collector at a steep 30 degree angle from vertical (winter position) . So, right now, i see no good reason to switch to thermosyphon or pump system . Its a very basic system and works out well for all my hot water needs , which admittedly, are minimal. I will post a URL of the project soon.