From Earlham Cluster Department
Mounting the Solar Heater
- We have decided to mount the solar heater on a platform that we will build along the southern wall of the house rendering most of the below information moot. It will be easier to see and demonstrate on, it will hopefully be raised beyond the reach of thrown objects from lawnmowers and the like and will be a good deal easier to set up than on the roof. The only thing that might happen is that we will experience more shade, but hopefully that will be minimal. The mounting platform already installed on the roof will be used for PV panels later hopefully but already serves as a good bench.
- These are the measurements for rails made of 2x4s with which to ramp up against the side of the house to slide the solar panel. The slant of the roof is roughly 22 degrees. This measurement was made with a level a piece of paper lined up with roof and a protractor. Paper trigonometry was abandoned for the most part in figuring the length of the rails as the ground immediately south of that side of the house is sloping. Measurement was taken by leveling a construction protractor and stretching a measuring tape to the desired angle. The wall is 9'4" high a 55 degree angle would need about 12' 8" of wood. A 45 degree angle would need about 15'3" of wood. These measurements were checked on paper with the law of cosines and were declared sound, a little long even.
- Since the panel will be mounted in a fixed position, we must decide on the optimal angle taking into consideration our latitude and Miller Farm energy usage. Charles R. Landau examines optimum angle in a little more detail than is usually presented (e.g. +/- 15 degrees latitude), though we have not examined his results closely enough to determine their accuracy.
- Because the occupancy at Miller Farm is greatly reduced during the Summer months, we can clearly see in the historical data that energy use during those months is very low. As one might expect, energy use during the winter is at its peak. Therefore, it seems that we could achieve the best all year results by setting our panel somewhere between the spring/fall and winter optimum angles.