Expansion of water

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

jebatty

Minister of Fire
Jan 1, 2008
5,796
Northern MN
After running a quick search did not find answer in this forum as to how much water expands with temperature, which is important in sizing a non-pressurized tank and in sizing an expansion vessel in a presurized system.

after *oogling this, these are helpful:
http://www.newton.dep.anl.gov/askasci/chem03/chem03335.htm
http://www.ucdsb.on.ca/tiss/stretton/chem2/data19.htm

A statement made is "from freezing to boiling, [expansion] is 4.3%." Looking at the data table, seems to indicate that expansion in moving water from 50F (10C) to 200F (95C) is 3.8%. So, 1000 gal of storage needs at least 38 gallons of expansion over this temp range. Plus a margin of error -- maybe plan for 5% as a rule of thumb?
 
Joe Brown did some rough calculations and I think his conclusion was that with 1,000 gallons of pressurized storage you could get away with a 40-gallon (hw) tank, but that 80 would be the safe bet. It's around here somewhere--probably worth digging up, as he walked us through the calculations.

EDIT: Here it is; second page:

https://www.hearth.com/econtent/index.php/forums/viewthread/11559/P15/
 
Dude don't even mess with googling it,
You'll start getting confused with acceptances, max acceptance, volume, and what the manufactuter wants.
Find the Tank(brand, mfctr,model) you want, then adjust the pick based on what like about the tanks and what manufacturer says its capable of.

Use this as an example

http://www.mmcontrol.com/documents/pdfs/Cashacme/tv.pdf
 
Status
Not open for further replies.