We have a geo system with DSH and 2 tank system. The tank for the DSH is just a standard 40 gal electric hot water heater with the electric elements not hooked up. Talk to your installer on the ideal size, but I'm not sure I'd go much larger than 40 as the DSH will use some of your heating energy to operate in the winter months. There is no reason to maintain and heat an 80 gal DSH tank unless you really need that much. A 40 gal DSH tank in series with a 40 gal hot water heater is a lot of hot water. Do some research, but I think you'll find that a 2 tank setup is the recommended way to set up a DSH for the best efficiency.
For us, the DSH supplies almost all our hot water during the heating season, and very little of it during the non-heating season, as we don't use ac a lot.
For us, the DSH supplies almost all our hot water during the heating season, and very little of it during the non-heating season, as we don't use ac a lot.
