TANKS
Tanks
| The following shall be the specifications for the solar thermal storage tank. Storage tank shall be TrendSetter Industries model and shall be of the drainback (atmospheric-pressure) type. Storage tank shall be tested and evaluated in conformance with Solar Rating and Certification Corporation (SRCC) system standards. Standard systems shall also be certified by the SRCC. The tank and heat exchangers shall be manufactured and labeled in conformance with Appendix L of the Uniform Plumbing Code. |
The storage tank frame shall be of composite construction incorporating thermal breaks, aluminum extrusions and insulating materials. The lid assembly will incorporate provisions for mounting one or more immersed-style heat exchangers (inlet & outlet), solar returns, sensor wells. The tank side body will incorporate provisions for one or more pump assemblies incorporating a shutoff valve and hose bib. All fasteners shall be stainless or non-ferrous. One or more bulkhead fittings shall be installed in the lid assembly for interior inspection purposes.
INSULATION
The insulation shall be 1lb/ft3 density expanded polystyrene (EPS) of 3” thickness on walls and lid (with a 1.5” thickness on the base), sheathed in textured aluminum of .02” thickness and held in place with a laminating backer. A thermal barrier of ¼” thickness shall also be incorporated along the interior of the tank body for thermal isolation. The lid assembly containing the plumbing fixtures shall contain closed-cell foam insulation, as well as incorporating thermal breaks to minimize heat transfer to the exterior of the tank.
WALL SUPERINSULATION PACKAGE I, II
In addition to the standard insulation package above, tank walls will incorporate an additional 1” or 2” of Polyisocyanurate with a long-term R-Value of approximately 5.5 per inch of thickness. This insulation is mounted on the interior of the tank, so tank capacity will vary from nominal figures.
LID SUPERINSULATION PACKAGE
In addition to the standard insulation package above, tank lid will incorporate an additional layer of 1lb/ft3 density expanded polystyrene (EPS) of 3” thickness as standard, separated by an air gap from the standard lid. Provisions will be made for reconfiguring heat exchanger connections out of the side of the superinsulated lid.
HEAT EXCHANGERS (H-X)
The heat exchanger(s) shall consist of submerged arrays of 50’ x 0.012” thickness single-wall corrugated type 316L stainless steel heat exchangers with ¼”, 1”, 1.25” or 1.5” MIP diameters and fittings. The maximum recommended working pressure is 147 psi and service temperature of 212°F. The following graphs represent tested performance and friction loss for the specified heat exchanger. The heat exchangers shall be approved by UL and manufactured under ISO 9001 standards.
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GPM |
NOMINAL SIZE (ID) |
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3/4" |
1" |
1-1/4" |
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1 |
1.10 |
0.05 |
0.00 |
||
2 |
0.35 |
0.10 |
0.05 |
||
3 |
0.70 |
0.25 |
0.10 |
||
4 |
1.20 |
0.45 |
0.15 |
||
5 |
1.80 |
0.65 |
0.25 |
||
6 |
2.55 |
0.90 |
0.35 |
||
7 |
3.35 |
1.20 |
0.45 |
||
8 |
4.30 |
1.55 |
0.60 |
||
9 |
5.35 |
1.90 |
0.75 |
||
10 |
6.50 |
2.30 |
0.90 |
||
11 |
7.75 |
2.75 |
1.05 |
||
12 |
9.15 |
3.25 |
1.25 |
||
13 |
10.60 |
3.75 |
1.45 |
||
14 |
12.15 |
4.30 |
1.65 |
||
15 |
13.80 |
4.90 |
1.85 |
||
20 |
23.50 |
8.35 |
3.20 |
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Pressure loss in feet of head for a 50' coil |
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