Page 323 - Handbook of Energy Engineering Calculations

percent of the building’s floor area, depending on geographic location,
amount of insulation, and ratio of wall-to-glass area in the building design.

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2
b. For space cooling, allow 250 to 330 ft (23.3 to 30.7 m ) of collector
surface for every ton of absorption air conditioning, depending on unit
efficiency and solar intensity in the area. Insulate piping and vessels

adequately to provide fluid temperatures of 200 to 240°F (93.3 to
115.6°C).

2
2
c. Size water storage tanks to hold between 1 and 2 gal/ft (3.8 to 7.6 L/m )
of collector surface area.

d. In larger collector installations, gang collectors in series rather than
parallel. Use the lowest fluid temperature suitable for the heating or
cooling requirements.

e. Insulate piping and collector surfaces to reduce heat losses. Use an overall
2
2
heat-transfer coefficient of less than 0.04 Btu/(h · ft · °F) [0.23 W/(m ·
K)] for piping and collectors.

f. Avoid water velocities of greater than 4 ft/s (1.2 m/s) in the collector tubes,
or else efficiency may suffer.

g. Size pumps handling antifreeze solutions to carry the additional load
caused by the higher viscosity of the solution.

Related Calculations. The general guidelines given here are valid for solar
heating and cooling systems for a variety of applications (domestic,
commercial, and industrial), for space heating and cooling, and for process

heating and cooling, as either the primary or supplemental heat source.
Further, note that solar energy is not limited to semitropical areas. There are
numerous successful applications of solar heating in northern areas which are
often considered to be “cold.” And with the growing energy consciousness in

all field, there will be greater utilization of solar energy to conserve fossil-
fuel use.
Energy experts in many different fields believe that solar-energy use is