open issue - Plumbing Engineer

Solar Solutions
Continued from page 40
return can change.
The sweet spot in this example
appears to be in the middle of the
‘knee’ of the curve where 70-80% of
the annual heat load is provided by
solar. This number of collectors can
be pumped with a single circulator
and so the extra complexity of using
two banks with two pumps is avoided.
And it is interesting to note that
the annual solar contribution is nearly
doubled when useful heat can be
collected throughout the summer
season. This might be good to keep
in mind the next time a solar heating
opportunity comes along at a motel,
B&B, public building or other reasonable
location where a swimming
pool might
Final notes
These articles are targeted toward
residential and small commercial
buildings smaller than 10,000 square
feet. The focus is on pressurized glycol/hydronic
systems since these
systems can be applied in a wide
variety of building geometries and
orientations with few limitations.
Brand names, organizations, suppliers
and manufacturers are mentioned
in these articles only to provide
examples for illustration and discussion
and do not constitute any recommendation
or endorsement. The
simulation modeling and graphics
presented here were accomplished
using “SLASH-D” software from
SolarLogic. n
Bristol Stickney has been designing,
manufacturing, repairing and installing
solar hydronic heating systems for more
than 30 years. He holds a Bachelor of
Science in Mechanical Engineering and
is a licensed Mechanical Contractor in
New Mexico. He is the Chief Technical
Officer for SolarLogic LLC in Santa Fe,
N.M., where he is involved in development
of solar heating control systems
and design tools for solar heating professionals
(visit www.solarlogicllc.com
for more information).
In this series of articles, I have
been making the case that the key
ingredients for solar/hydronic
design and installation can be divided
into six categories, roughly in
order of their importance.
1. Reliability
2. Effectiveness
3. Compatibility
4. Elegance
5. Serviceability
6. Efficiency
The success of any solar hydronic
home heating installation depends
on the often-conflicting balance
between any of these six principles.
Finding the balance between them
defines the art of solar heating
design.
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The views and opinions expressed in this column
are those of the author and do not reflect those
of Plumbing Engineer, TMB Publishing, or ASPE.
Page 42/Plumbing Engineer April 2012