Beckett SolarHot - Manual (Page 10)

6
© SOLARHOT 2006-2009
Sizing the heat exchanger: There are several different types of heat exchangers available on the
market today, including hot water tanks that have integral heat exchangers built in. Each one of these
methods works by moving the cold storage tank water past the heat exchanger before being deposited
back nto the storage tank. At the same tme, the hot water from the collector loop s pumped on the
other side of the heat exchange surface and then back up to the collectors. A system with a properly
designed heat exchanger will transmit the heat from the collector loop to the storage tank quickly.
Generally speakng, the larger the surface area, the better the heat transfers. If you undersze the heat
exchanger, your pumps will run longer to extract the heat from the collectors and reduce the energy
saved with the system. The larger the heat exchanger, the higher the cost. You want as much heat
exchanger surface area as you can afford.
The Beckett SolarHot Advantage: SolarHot has uniquely created the SolVelox
package, whch pre-assembles and ntegrates an overszed, stanless steel heat
exchanger along with the pumps and valves necessary to drive a two-loop solar
system. The heat exchanger and pumps are sized to meet the heat output of up to 6
solar collectors, so one SolVelox appliance provides an economical solution as you
scale the solar system to meet your particular needs. It is externally mounted in order
to reduce mantenance ssues.
Chapter 4: Choosing a System
The first question you have to answer before you can accurately choose a system is to determine
whether t freezes n your locaton. Go to http://www.ncdc.noaa.gov/oa/climate/online/ccd/lowtmp.txt.
Ths webste covers the lowest temperature on record for all of the government’s major weather statons
throughout the country. If t never freezes n your area, then the best system you could own s an open
loop system. Ths system has no heat
exchanger between the storage tank and
the collector. Based on a sensor mounted
on the collectors and a sensor mounted on
the bottom of the storage tank, t detects
when there s more heat n the collectors
and actvates a pump to capture that heat.
It crculates water from the bottom (whch
s colder than the top) of the storage tank
through the collectors to pck up the heat
and then back to the storage tank. Once
the collectors are close to the same