Solar Thermal Information

Caleffi North America, Inc.
9850 South 54
th
Street
Franklin, WI 53132
T: 414.421.1000 F: 414.421.2878
Dear Hydronic Professional,
Welcome to the 2
nd
edition of idronics – Caleffi’s semi-annual design journal for
hydronic professionals.
The 1
st
edition of idronics was released in January 2007 and distributed to over
80,000 people in North America. It focused on the topic hydraulic separation. From
the feedback received, it’s evident we attained our goal of explaining the benefits
and proper application of this modern design technique for hydronic systems.
If you haven’t yet received a copy of idronics #1, you can do so by sending in the
attached reader response card, or by registering online at www.caleffi.us
. The
publication will be mailed to you free of charge. You can also download the
complete journal as a PDF file from our Web site.
This second edition addresses air and dirt in hydronic systems. Though not a new
topic to our industry, the use of modern high-efficiency equipment demands a
thorough understanding of the harmful effects of air and dirt, as well as knowledge
on how to eliminate them. Doing so helps ensure the systems you design will
operate at peak efficiency and provide long trouble-free service.
We trust you will find this issue of idronics a useful educational tool and a handy
reference for your future hydronic system designs. We also encourage you to send
us feedback on this issue of idronics using the attached reader response card or by
e-mailing us at [e-mail].
Sincerely,
Mark Olson
General Manager,
Caleffi North America, Inc.
A Technical Journal
from
Caleffi Hydronic Solutions
Caleffi North ameriCa, iNC
3883 W. Milwaukee Rd
Milwaukee, Wisconsin 53208 USA
Tel: [phone]
FAX: [phone]
E-mail: idronics@caleffi.com
Website: www.caleffi.us
To receive future idronics issues
FREE, register online www.caleffi.us
Dear Hydronic Professional,
Welcome to the 6
th
edition of idronics, Caleffi’s semi-annual design journal
for hydronic professionals.
The global recession has slowed nearly all industries over the past year.
However, despite declines in construction, solar water heater shipments
in the US increased 50% during 2008.
As more and more HVAC professionals become familiar with solar water
heating, many recognize opportunities to extend solar thermal technology
for combined domestic hot water and space heating applications. This is a
trend our parent Caleffi SpA identified several years ago in Europe, and is
now a topic of growing interest here in North America. For this reason,
solar “combisystems” was selected as the topic for this edition of idronics.
Caleffi is pleased to provide the information in this edition to assist those
designing solar combisystems. We also stand ready with state-of-the-art
hardware to support installation of such systems.
We encourage you to send us feedback on this edition of idronics by
e-mailing us at idronics@caleffi.com.
Finally, if you are interested in previous editions of idronics, please go to
www.caleffi.us where they can be freely downloaded. You can also register
to receive future issues online.
3 INTRODUCTION
3 FUNDAMENTALS OF SOLAR COMBISYSTEM DESIGN
Essential Design Principles
Instantaneous Collector Efficiency
Freeze Protection
6 SPACE HEATING OPTIONS
Heated Floor Slabs
Heated Thin-Slabs
Other Site-Built Radiant Panels
Panel Radiators
Forced-Air Distribution Systems
13 ANTIFREEZE-BASED SOLAR COMBISYSTEMS
Advantages of Antifreeze-Based Systems
Disadvantage of Antifreeze-Based Systems
Heat Dump Provisions
Antifreeze-Based Combisystem Designs
Antifreeze-Based Combisystem #1
Antifreeze-Based Combisystem #2
Antifreeze-Based Combisystem #3
Antifreeze-Based Combisystem #4
Antifreeze-Based Combisystem #5
Using a Pool as a Heat Dump
23 DRAINBACK SOLAR COMBISYSTEMS
Advantages of Drainback Systems
Disadvantages of Drainback Systems
Open-Loop vs. Closed-Loop Drainback Systems
Operation of a Drainback System
Siphon Limitations
Sight Glasses
Tank Piping Connections
Drainback Combisystem #1
Drainback Combisystem #2
Drainback Combisystem #3
Drainback Combisystem #4
40 PERFORMANCE EXPECTATIONS
Estimations
f-chart Analysis
Case Studies
Collector Orientation in Combisystems
Storage Tank Size in Combisystems
44 SUMMARY
45 APPENDIX A: Piping Symbol Legend
46 APPENDIX B: Heat Exchanger Performance
48 APPENDIX C: Tank and Piping Volume Formulas
49 APPENDIX D: Unit Conversion Factors
Product Information Pages
Caleffi North America, Inc.
3883 W. Milwaukee Rd
Milwaukee, Wisconsin 53208
T: 414.238.2360 F: 414.238.2366
© Copyright 2009
Caleffi North America, Inc.
Printed: Milwaukee, Wisconsin USA
INDEX
291711 Idronics_all.indd 2 10/20/09 10:39:38 PM