Water Volume in an Closed Loop System
Water Volume in an Closed Loop System
(OP)
Hi all,
I was wondering how to calculate the required volume in a hot-water closed loop.
Interested to know how much volume of water will be necessary to fill the system and also to calculate volumetric expansions.
Thanks
I was wondering how to calculate the required volume in a hot-water closed loop.
Interested to know how much volume of water will be necessary to fill the system and also to calculate volumetric expansions.
Thanks





RE: Water Volume in an Closed Loop System
For expansion, search this site for water expansion or perhaps, hydrostatic test pressure change as the same calculations often apply. I think there's an FAQ on the pipelines page which gives expansion formulae or just google it for charts which give you change in volume per degree.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Water Volume in an Closed Loop System
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Water Volume in an Closed Loop System
http://sunearthinc.com/design-resources/sizing-exp...
As to how big a system you need, that will depend on what you are trying to heat and what you have as a heating source.
Cheers,
John
RE: Water Volume in an Closed Loop System
For calculating the expansion vessel volume I would need to know how much volume of water is actually is in my loop. Is it only a factor of pipe capacity?? So pipes total lenght and thereby total volume capacity?
I know the volumetric flow rate (per hour) but since its a loop, I cannot figure out actually how much volume I would require (for initial filling of the system and also for other calculations eg. expansion volume)
The Table you sent " Pipe Capacity (US Gal/100 ft)" is upto 3" pipe, I guess I will keep googling more then...
Thanks again
RE: Water Volume in an Closed Loop System
It is essential to know the length of pipe in the system, then multiplying by cross sectional area gives volume in the piping. Then just add a bit for the expansion tank (once you work out the size of that, but not full), and it's done!
Cheers,
John
RE: Water Volume in an Closed Loop System
Yup got it now.
Thanks ;)
RE: Water Volume in an Closed Loop System
Usually you do not include elbow length (or bend length) in pipe weight calc's for pipe supports and hangers. Straight-line (work-point-to-work-point) distance approximations are adequate for weight purposes.
HOWEVER, here you need to accurately use the weld-to-weld distances for INTERNAL diameter of the pipe in the design, AND then add in the INTERNAL volume of every elbow or bend AND add in the INTERNAL volume of your heat exchangers, tanks, and valves and pumps.
And, uh, internal volume of pipe can be calculated (not just from Google)
volume = length x 3.14 x [(internal dia)/2]2
Do you know the internal volume of one-quarter of a torus? 8<)
RE: Water Volume in an Closed Loop System
RE: Water Volume in an Closed Loop System
Yeah I did actually calculated all my pipes volume... but wanted to check it with google values as well.
I dont think I can do straight line lenght calculations for the coils (its have over 100 bends). So I added everything as you said.
Thanks