文档介绍：SDHW Installation Basics
Part 2: Closed Loop Antifreeze
Chuck Marken & Ken Olson
©2003 Chuck Marken & Ken Olson
Closed loop antifreeze
is one of the most
common solar domes-
tic hot water (SDHW)
systems for cold
climates. This article
concentrates on the as-
sembly and installation
of closed loop anti-
freeze SDHW systems,
hereinafter referred to
as closed loop sys-
tems. “Installation
Basics for SDHW
Systems” in HP94
covered aspects of
mon to
most solar water
heating installations,
such as collector
location and mounting,
pipe runs, soldering
and insulation, and the
control system.
Nancy Cochrell of AAA Solar puts the
finishing touches on a SDHW system.
42 home power 95
hot water how to
The operation of the closed loop
system, the function of each of its
components, and some guidelines for
sizing were covered extensively in
HP85. In brief, freeze protection is
plished by circulating a nontoxic
antifreeze fluid to remove heat from
the solar collectors and transfer it to
the domestic water via a heat
exchanger. The antifreeze remains
contained within a closed loop, so it
never mixes with the domestic water.
The collector loop setup is nearly
identical to conventional closed loop
hydronic home heating systems,
which circulate water heated in a
boiler through baseboard radiators or
a radiant floor. Most plumbing and
heating contractors recognize the
closed loop system as mon
design and are familiar with all the
Laying out ponents and plumbing parts in advance
components on the parts list in this prevents headaches after the soldering begins.
article.
Modular Assembly Rules! SDHW Module
The ponents, other than solar collectors and for Use with In-Tank
storage tanks, are easier to deal with if you have the space to
assemble the parts into ponent module before Heat Exchanger
installation. Many modules in earlier systems had cosmetic
covers, but this has been shown to cause ex