Storage Questions

[ManiacPD]

I have a few questions for those of you who are experienced with water tanks for heat storage:

1. I have found a 600 gallon milk tank in very good shape to use for storage. It is the round style with some small bungs in the top and one large, oval opening with a gasketed cover. The price is reasonable but before I buy it will that be large enough? Heat is coming from a Memco MW100 boiler. I see many of you using 800 - 1,000 gallons of storage. I don't want to buy the tank if it isn't big enough. Some friends have told me any storage is better than none but I don't want to do this twice (or more).
2. As far as HX goes, how should I go about that? I need one to dump the heat into the tank from the wood, and one to take it away to my oil boiler, correct? Obviously I can't pressurize the tank so how do you transfer the Btus?
3. How are you insulating these things? I need to fight standby losses as my garage is insulated but unheated at the current time.
4. I'd like to be able to run this year round for domestic HW in the summer. We use a ton of hot water with two small children as many of you can relate. Do any of you do the same thing?

Thanks for your input!

 

[Nofossil]

600 gallons is on the small side. In part, it depends on your heat load and the type of system that you have. A small house with radiant floors might be fine with 600 gallons, where a large house with baseboards would not be as happy.

There's lots more to consider, but it's also true that something is better than nothing. Study a few of the storage threads and give us an idea of your heating system and heat load.