Calculating liquid heat storage

Geo NR Gee · 01-21-19, 02:33 PM

I have two 375 gallon insulated steel storage tanks. They were used for storing hot water generated from 180 evacuated solar tubes. I am trying to figure out if I should keep them and use them with the 90 evacuated solar tube system for space.

They are tall vertical tanks and could fit next to the
collectors. The tanks do not have any heat exchangers in them. They do have several ports for temperature probes and other fittings. This unit has a manway for easy access.

On a sunny day, the evacuated tubes generate 185* F (85*C) or more. They are supposed to have a snap disc to limit the heat to 195* F.

I don't know how to figure out the amount of heat energy that the storage tanks could store. I contacted the manufacturer and they don't have much information on them besides a simple installation, startup and maintenance procedures. These tanks are thermally coated with a spray foam. I believe it is 2 inches.

The plans are to use the heat generated from the collectors for space heating in my house and garage, dhw heating, radiant floor heating and the rest goes down in the ground for charging my future geothermal system.

Does someone have a calculator or know of one to figure this out?

We could just pour a small concrete pad, set the tank/s, plumb them and see what kind of temperatures they would store and if it would be enough to get us heat for the night or for a few cloudy days?

01-21-19, 02:33 PM	#1
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Calculating liquid heat storage I have two 375 gallon insulated steel storage tanks. They were used for storing hot water generated from 180 evacuated solar tubes. I am trying to figure out if I should keep them and use them with the 90 evacuated solar tube system for space. They are tall vertical tanks and could fit next to the collectors. The tanks do not have any heat exchangers in them. They do have several ports for temperature probes and other fittings. This unit has a manway for easy access. On a sunny day, the evacuated tubes generate 185* F (85C) or more. They are supposed to have a snap disc to limit the heat to 195 F. I don't know how to figure out the amount of heat energy that the storage tanks could store. I contacted the manufacturer and they don't have much information on them besides a simple installation, startup and maintenance procedures. These tanks are thermally coated with a spray foam. I believe it is 2 inches. The plans are to use the heat generated from the collectors for space heating in my house and garage, dhw heating, radiant floor heating and the rest goes down in the ground for charging my future geothermal system. Does someone have a calculator or know of one to figure this out? We could just pour a small concrete pad, set the tank/s, plumb them and see what kind of temperatures they would store and if it would be enough to get us heat for the night or for a few cloudy days?