Revised May 2005
Table 1. Comparison of existing FSEC Energy Factor (EF) ratings and new FSEC EF ratings for representative generic systems |
System Type | Collector Area (ft2) /Tank |
North |
Central & South |
|||
Existing EF |
New EF |
Existing EF Central & South |
New EF Central |
New EF South |
||
Drainback-Sidearm HX |
40/80 |
1.7 |
1.7 |
1.7 |
2.1 |
2.3 |
Drainback-Tank Wrap HX | 40/80 |
1.5 |
2.0 |
1.6 |
2.4 |
2.5 |
Drainback-Tank Wrap HX | 48/80 |
2.5 |
2.3 |
2.6 |
2.8 |
2.9 |
Drainback-Tank Wrap HX | 64/80 |
2.2 |
2.6 |
2.3 |
3.3 |
3.5 |
Indirect Tank Wrap HX Glycol |
40/80 |
2.3 |
2.6 |
2.5 |
3.4 |
3.9 |
Direct - Diff | 32/52* |
2.1 |
2.3 |
2.2 |
2.9 |
3.4 |
Direct - Diff | 40/80 |
2.7 |
2.9 |
2.8 |
4.2 |
4.7 |
Direct - Diff | 40/80 |
2.7 |
3.2 |
2.9 |
4.9 |
6.4 |
Direct - PV | 32/80 |
2.6 |
3.4 |
2.7 |
5.3 |
6.9 |
Direct - PV | 40/80 |
4.1 |
4.4 |
4.5 |
8.4 |
13.2 |
Direct - PV | 40/80 |
3.3 |
4.5 |
3.6 |
8.6 |
13.8 |
Single ICS | 32/41 |
4.1 |
1.9 |
4.9 |
2.2 |
2.4 |
Single ICS | 25/42 |
3.4 |
1.7 |
4.0 |
1.9 |
2.1 |
Double ICS | 64/82 |
>15 |
2.9 |
>15 |
3.8 |
4.6 |
Double ICS | 50/84 |
>15 |
2.4 |
>15 |
3.1 |
3.6 |
Drainback - Sidearm HX: Indirect drainback forced circulation, flat plate collector, solar tank with upper element, side-arm heat exchanger with natural convection loop, AC pump, and differential controller.
Drainback - Tank Wrap HX: Indirect forced circulation, flat plate collector, solar tank with upper element and wrap around heat exchanger, AC pump, and differential controller.
Indirect - Tank Wrap HX: Indirect forced circulation, flat plate collector, solar tank with upper element and wrap around heat exchanger, AC pump, and differential controller.
Direct - Diff: Direct forced circulation, flat plate collector, solar tank with upper element, AC pump, and differential controller. (*Tank is 52 gal conventional electric retrofitted for solar.)
Direct - PV: Direct forced circulation, flat plate collector, solar tank with upper element, 24V DC pump, and 20-Watt photovoltaic module.
Single ICS: Integral collector storage, includes a 50-gallon electric auxiliary tank in system.
Double ICS: Integral collector storage, includes a 50-gallon electric auxiliary tank in system.