3 ms·

I think a better design would be to construct a reinforced holding tank underground (either underneath the basement or adjacent to the house) that would hold th

I think a better design would be to construct a reinforced holding tank underground (either underneath the basement or adjacent to the house) that would hold the NaOH solution, then lay piping and use a pump to circulate small amounts of it to a heat exchanger in a central ventilation system. Wikipedia notes that it reacts with aluminum but not with iron. Iron is relatively plentiful as well and we know how to build holding tanks with that material. It's probably not a good idea for earthquake-prone areas, but this method might work ok in places like Minnesota to replace burning LNG in a furnace or coal-plant-powered electric heating as the primary source of heat in the winter. I guess it depends on the reaction rate and efficiency of the system - how many tons of NaOH would be required to heat the house throughout the entire winter?

jerf 10y ago
"how many tons of NaOH would be required to heat the house throughout the entire winter?" This is one of those cases where the fact that it wasn't mentioned leads me to believe "embarrassingly large amounts". (That said, the technique may not be useless, and they may have a valuable machine. It's just that this particular application is setting off my energy-scale alarms. Press releases tend to get pretty breathless.)
- logfromblammo 10y ago
  I have worked with NaOH before, and I think the amount required would probably be more than a (US tank-style) water heater and less than a typical above-ground swimming pool. I think you would need some of the tables typically found in chemical engineering manuals to work out the exact amount. You would need the heat capacities for 50% and 30% (wt%) aqueous NaOH, mass fractions, enthalpy of dilution, and maybe activity coefficients. It sounds like a homework problem for a ChemE student.
  - jerf 10y ago
    Yeah, I never took enough chemistry to be confident I could get that correct or I would have done it myself. I've done Physics 101 BotE work on HN before but I'm pretty sure I'd have screwed this up. :)

jerf 10y ago

"how many tons of NaOH would be required to heat the house throughout the entire winter?" This is one of those cases where the fact that it wasn't mentioned leads me to believe "embarrassingly large amounts". (That said, the technique may not be useless, and they may have a valuable machine. It's just that this particular application is setting off my energy-scale alarms. Press releases tend to get pretty breathless.)

logfromblammo 10y ago
I have worked with NaOH before, and I think the amount required would probably be more than a (US tank-style) water heater and less than a typical above-ground swimming pool. I think you would need some of the tables typically found in chemical engineering manuals to work out the exact amount. You would need the heat capacities for 50% and 30% (wt%) aqueous NaOH, mass fractions, enthalpy of dilution, and maybe activity coefficients. It sounds like a homework problem for a ChemE student.
- jerf 10y ago
  Yeah, I never took enough chemistry to be confident I could get that correct or I would have done it myself. I've done Physics 101 BotE work on HN before but I'm pretty sure I'd have screwed this up. :)