storage questions

[mech644]

So I've read through most of the stick'ed info above and have a some questions about storage specifically and boiler setups in general.
Utilizing my existing boiler/mechanical room masonry walls I can build in two non-pressurized storage tanks of 750 gl per. One tank would be oriented horizontally and the other vertically.
I'm assuming vertical orientation is preferable, correct? If so, assuming equal tank size and insulation is there a quantifiable gain?
Anyone ever used fiberglass for a tank liner? The FRP would not be relied on for structural strength, only as a watertight barrier (vinylester resins).
Quantifiable gains to using a pressurized tank vs non? Less pumps and HX's for sure, but is the thermal extraction more efficient?

Cape of 1955 construction, footprint is 1350', finished basement so 2700 sq' to heat (only attic upstairs); brand new Trane OHWB, base board distribution; lined brick chimney, 3 flues.
House is actually very tight, but R20 walls and R20 ceiling don't hold much heat for very long.
Big improvements to the thermal envelope will, overtime, bring the Btu demand of the house down. After the boiler is online I'll start replacing much of the HWBB with underfloor radiant.
Looking at the Eko 25, primarily because of price; though the V's, Froling, Biomass, and Attack look very nice. But they are out of my budget.
The 25 will be undersized from the start but in 3 to 4 years things will be much improved.

Thanks for any and all comments and thoughts.

 

[kjahnz]

I have seen vinyl ester Fiberglas used as a secondary liner in the petrol chemical storage tank industry for nearly 20 years. On a 10 year inspection rotation, not one of them were leak free. Non of them held heated product especially at 185 degs. I would not suggest using it for a water tight coating in a high temp water tank. Belzona might work if you could afford it.

 

[mech644]

What type of leak; at a penetration fitting, failure of the laminate or a secondary bond? Wear through caused by tank creep (expansion/contracting against an abrasive element?
High pressure LP and NG tanks are routinely made from spun FRP; there are many diesel and gasoline tanks in boats that have been trouble free for decades (until E10 anyway).
I would think that filtered and treated water would be fairly benign as compared to petrol chemicals.

 

[kjahnz]

most leaks form at the floor to wall transition, others are from surface preparation, others are from improper resin to cure agent ratios and or cure temp parameters. Expansion and contraction of two dissimilar materials will be a cause of de-lamination after time. Patching is a cure for the leaks, and will hold, but for how long?

 

[jebatty]

I considered FRP some years ago and then decided a retired LP tank is easier, safer, and trouble free. I know size and handling of LP tanks or other metal tanks is a cost and physical issue.

When I designed my new shop and moved the tank and Tarm into the new shop, the shop dimensions and large entry door made it easy to put a 19' steel LP tank horizontal along an end wall with the boiler right next to it to fill the entire end wall, plus a 4' door to the wood stacks behind the shop which hold about 10 cords of c/s/s wood. I boxed in and insulated the tank, the top of the "box" is storage space for all sorts of things, no real loss of floor space.

 

[Woodfarmer1]

if i were to use an uninsulated stainless steel bulk milk tank should it go in the unheated shop beside my boiler or down in the basement?

 

[peakbagger]

Talk to Tom in Maine, he makes custom PVC liners for tanks. There are very few barrier coatings that would hold up well that you could afford. Generally masonary water tanks have rebar in the walls and in the corners to resist the sidewise loading. A standard foundation wall doesnt.

 

[Wolftech]

I built my 900 gallon tank right on the side of my shed. Cost was cut since I had ripped up 3/4 plywood from the floors I have redone with radiant heating. Size is 18 feet long 4 foot high and 2 foot wide. If you have some of construction supplies around you might think build one.

 

[NE WOOD BURNER]

Looking at the Eko 25, primarily because of price; though the V's, Froling, Biomass, and Attack look very nice. But they are out of my budget. The 25 will be undersized from the start but in 3 to 4 years things will be much improved.

I would start by having heat loss calculation performed on the house to size for your immediate load and projected thermal storage. In the heat loss calculations you could run what if scenarios to see if the size requirement for boiler will change much with your insulation and sealing for the future. Thinking out loud, but I think the insulation and sealing would be a good first investment rather than a possible undersized boiler with 1500 gallons of thermal storage.

FYI http://www.americansolartechnics.com/

(broken link removed to http://hudsonvalley.craigslist.org/for/4212625577.html)

 

[mech644]

I've spoken to Tom in Maine; wealth of information and knowledge, his tanks are probably a good value. I've already bought one truckload of rigid insulation from him and will undoubtebly be buying more. However cash is not what I have an abundance of. I do have an abundance of skill and resources to build, fabricate, or create stuff. I can't reasonably make insulation, but I can handle putting a tank together.
The house has 3 existing interior concrete walls that are ideal to use as the basis for a tank.
I've done the heat loss calc, lots more insulation is needed and am in the process of putting it in.

Wolftech, what did you use to line your tank?