Storing The Heat???????????

[Robby]

[ I use a Harman SF360 boiler and burn a lot of Lodgepole Pinewood. It seems to be very inefficient when idling as most of the heat goes up the chimney, but burns clean and judging by the temperature gauge, pretty efficient when draft open. Looking at Garn (and others) that store the heat in large volumes of water, I am looking at 1000 gal. propane tank,standing at a 45 degree angle, welding in outlets, bottom and top, a couple for aquastats and storing water at 180 to 190 degrees. That should be between 250,000 and 300,000 btu. Then I could run boiler in most efficent mode and heat would last from 24 hrs to 2 or 3 days depending on weather. It could still be a closed system, 20 psi, etc.

Anyone have experience doing this? Idea's?

The tank is free, good condition, but welding, insulating and housing are far from free.


Robby

 

[markpee]

A guy named Nofossil is a great resource on here - I'm sure he'll post. Thought there are some posts related to storage - search and you may find some of the answers you need.

 

[BrownianHeatingTech]

Storage is the best way to run a wood system. Pressurized (like you're looking at) and atmospheric tanks (with heat exchangers) each have their own advantages/disadvantages.

Getting a free tank (assuming you can clean the mercaptan out of it, and get it welded cheaply enough) eliminates one of the biggest disadvantages of pressurized storage.

Be aware that you will need a fairly-large expansion tank to go with it, because that amount of water will expand a good bit, when heated.

Joe

 

[Nofossil]

-- deleted double post - oops! ---

 

[Nofossil]

I'm with Joe 100% on this one. Unlike me, he does actual plumbing and knows what he's talking about ;-)

Storage can help a lot. !000 gallons is a nice size for most applications. Any reason for the 45 degree angle? There's a school of thought that says vertical is best, but for sure there are a lot of people using horizontal tanks and having excellent results. If you're welding fittings, it's a good time to think about ways to reduce turbulence and mixing as water is introduced and withdrawn. Largest possible diameter fittings, at a minimum. There's a thread around here somewhere with a lot of discussion on stratification ideas.

 

[Robby]

The reason for the 45 degree! I don't have the tank in front of me, but internet search says between 16 and 17 ft.long. I think I would need pretty strong construction to hold this thing vertical, narrow base, winds, etc. By boiler building is up against a bank that is about 45 deg. I thought build a good cradle, insulate, against hill. Maybe 45 deg better than horizontal. Welding, I don't think will be a problem, but cleaning, I don't know. My first thought was to leave tank on my trailer, fill 1/3 with water, add detergent, maybe dishwasher no sudsing and drive around. Rinse. Do again. Any ideas?

Robby

 

[stee6043]

I think you'd have a hard time supporting a 1000 gallon tank on a 45 degree angle. That sucker is going to want to go downhill something fierce. That'll be a lot of force on the bottom support in a unusual direction. When you support the tanks vertical or horizontal you're really only dealing with one axis. At a 45 you're going to have a pretty dynamic load....

 

[Robby]

Your probebly right. Vertical stratification would help, but to weld on legs strong enough, then look like a propane depot. I intended to put at least a foot of fiberglass insulation (2xR20) and some styrafoam, glued together then sloped water tight housing, plywood with roof. I think heat loss must be minimum or whole excersise a waste of money.

Just this morning the wood was used up overnight, needed a little more heat, then it will sit completley idle all day as sunshine and warm day will rquire little or no additional heat. If I have storage I would not need more fire untill at least this evening.

HAve a great day

robby