Hi,
A collector pointed SE or SW does pretty well.
I pasted in a couple runs from Radiation On Collector below.
The first is for a vertical collector pointed due south.
The 2nd is for a vertical collector pointed SE (a collector pointed SW would give the same results).
The last column (labeled Total) is the total solar radiation on the collector for a full sunny day per square foot of collector.
It looks like the SE and SW collectors are down about 20% from a south collector in mid-winter. You could just use more area to make up for this.
Here is an interesting excerpt from the Shurcliff book on the 45 degree oriented house/collector/reflector:
http://www.builditsolar.com/Experimental/ShurcliffPart1/S89pt5.htm
I guess its obvious, but SE will give you more morning heat and SW will give you more afternoon heat. Most people like the morning orientation.
Of course, you could use both.
This is the simple, cheap solar air collector I use on my shop -- 1 year payback where we live:
http://www.builditsolar.com/Projects/SpaceHeating/solar_barn_project.htm
You can download Radiation On Collector here:
http://www.builditsolar.com/Tools/RadOnCol/radoncol.htm
Collector pointed due south (ideal):
Month by Month Summary of Sun on Collector
(100% sunny weather)
Collector Area: 1.0 (sqft)
Collector Azimuth: 0.0 (deg) measured from South
Collector Tilt: 90.0 (deg) measured from horiz
Latitude: 42.0 (deg)
Altitude above SL: 0.0 (ft) Above Sea Level
Date ---- Sun ---------------- Collector -----------------------
Month Day Direct Di- Total Direct Difuse Total
Normal fuse
1 21 2099 122 2221 1629 61 1690
2 21 2525 151 2677 1663 76 1739
3 21 2887 205 3092 1424 102 1527
4 21 3094 301 3396 928 151 1079
5 21 3179 386 3565 591 193 783
6 21 3217 430 3647 459 215 674
7 21 3080 419 3499 559 209 769
8 21 2912 354 3266 868 177 1045
9 21 2684 249 2933 1318 125 1443
10 21 2355 171 2526 1573 85 1658
11 21 2026 127 2153 1580 64 1643
12 21 1845 106 1951 1517 53 1570
Sum 31904 3022 34926 14109 1511 15620
Radiation in BTU/day
Collector pointed SE (or SW):
Month by Month Summary of Sun on Collector
(100% sunny weather)
Collector Area: 1.0 (sqft)
Collector Azimuth: 45.0 (deg) measured from South
Collector Tilt: 90.0 (deg) measured from horiz
Latitude: 40.0 (deg)
Altitude above SL: 0.0 (ft) Above Sea Level
Date ---- Sun ---------------- Collector -----------------------
Month Day Direct Di- Total Direct Difuse Total
Normal fuse
1 21 2192 127 2320 1203 64 1267
2 21 2600 156 2756 1279 78 1357
3 21 2917 207 3124 1219 104 1323
4 21 3095 302 3397 1023 151 1173
5 21 3162 384 3545 836 192 1027
6 21 3181 426 3607 752 213 964
7 21 3061 416 3477 799 208 1007
8 21 2914 354 3268 956 177 1133
9 21 2713 252 2966 1127 126 1253
10 21 2429 176 2605 1202 88 1290
11 21 2121 133 2254 1168 67 1235
12 21 1974 113 2087 1134 57 1190
Sum 32359 3046 35404 12697 1523 14220
Radiation in BTU/day
