re: not so cold water supply... SOLAR.KnowledgePublications.com

re: not so cold water supply...
28 mar 1997
i wrote:

>this might make a nice solar closet, with a house around it and sunspace in
>front to keep it warmer. perhaps a few tanks side-by-side or stacked on top
>of each other (except in earthquake country) to store more water and heat...  

>start with a rectangular 1500 gallon septic tank that sits on the ground...

how would the water temperature change if this were say, in utica, ny, with an
average december temperature of 27 f, and 600 btu/ft^2/day of sun falling on
south walls, with a 4x16' sheet of clear plastic collector, with the south
side in a 70 f sunspace during the day, and the rest surrounded by a 70 f
house at night? 

>what will the average water temperature be (assuming the solar collector
>doesn't completely fill up with ice from condensing water vapor)? 

(some floating styrofoam beads or peanuts would help with this...)

energy in = 64ft^2x0.8x600btu/ft^2/day = 31k btu/ft^2/day?
 
          = 3hr(t-70)64ft^2/r1       "daytime" glazing loss 
	  +21hr(t-27)48ft^2/r20      nightime glazing loss  
          +24hr(t-70)48ft^2/r20      24 hour upper south wall loss
          +24hr(t-70)6x12/r20        24 hour lid loss
	  +24hr(t-70)8x24/r20        24 hour wall loss
          +24hr(t-70)6x12/r30        24 hour floor loss

          = (t-70)(192+86+230+58) + (t-27)50 = 616t - 40670 = energy out?

so t = (31k+41k)/616 = 117 f. seems promising, perhaps with the tanks stacked
2-high, with a 2x12x16' pool of water above the 2nd floor ceiling and sheet-
metal-clad 2x10 joist-fins underneath to add more thermal mass to the house,
so it can coast through a 24 hour average winter day, with an average amount
of sun, with no assist from the solar closet, which only helps heat the house
on cloudier days...  

nick