a measure of solar house heating ease SOLAR.KnowledgePublications.com

a measure of solar house heating ease
3 jul 1996
how hard is it to make a 100% solar heated house in various parts of the us? 

norman saunders, pe, uses a simple measure:

       average sun that falls on a south wall
   e = --------------------------------------.
         70 f - average outdoor temperature

the higher the number, the easier the climate. here are some values
for a few cities using some nrel average weather data:

                   jan    s wall              dec    s wall
                   temp   sun       e         temp   sun      e       

abilene, tx        42.8   1400      51        45.5   1400     
albuquerque, nm    34.2   1640      46        35.3   1610
atlanta, ga        41.0   1120      37        44.5   1110
austin, tx         48.8   1200      57        56.6   1200
binghamton, ny     21.1   790       16        26.5   610      14
bismark, nd         9.2   1070      18        14.0   1110
boulder, co        29.7   1370                31.0   1180     30
buffalo, ny        23.6   680                 29.1   550      13
carabou, me         8.9   990       16        14.8   780
chicago, il        21.0   910       19        26.6   740      17
concord, nh        18.6   1060      21        24.3   880      19
detroit, mi        22.9   770       16        28.3   610      15
flagstaff, az      28.7   1580      38        29.6   1560
fresno, ca         45.7   880                 45.4   830      34
new york city, ny  31.5   980       25        36.6   860      26
phila, pa          30.4   1000      25        35.8   900      26
raleigh, nc        38.9   1130      36        42.6   1100
richmond, va       35.7   1090      32        40.1   1030
san francisco      48.7   1050      49        49.4   1050
seattle, wa        40.1   480                 40.5   420      14

it looks like steve baer has it easy in albuquerque, as do people in texas :-)
but norman has designed 100% solar houses even in places like binghamton...

nick