I have used heat storage of 1000 gallons for thirty years but would really like another 250,000 btus of usable storage. In the 70s, before wood gasification, insulated bladder tanks and pressurized storage tanks, there was a movement to build concrete cisterns under the floor of a house, fill it with river rock and pump the water from boiler into this pit for heat storage. With advent of the Jetstream and the GARN, this form of storage disappeared.
Has any one ever tried adding grapefruit size river rock to a storage tank to increase the storage of the tank? Does anyone know what the btu storage capacity of 1 lb of rock?
My tank is constructed of 5/8" riveted boiler plate and is sitting on reinforced concrete saddles. It could accommodate the extra weight of about 4 yards of this rock which would be about 10,000 lbs. The rock would displace about 400-500 gallons of water.
I have left myself open on this one. Any ideas from anyone?
Allan
Has any one ever tried adding grapefruit size river rock to a storage tank to increase the storage of the tank? Does anyone know what the btu storage capacity of 1 lb of rock?
My tank is constructed of 5/8" riveted boiler plate and is sitting on reinforced concrete saddles. It could accommodate the extra weight of about 4 yards of this rock which would be about 10,000 lbs. The rock would displace about 400-500 gallons of water.
I have left myself open on this one. Any ideas from anyone?
Allan