LAARS DuraFlow - Installation, Operation and Maintenance Instructions - Manual (Page 3)

DuraFlow Water Heater Page 3
SECTION 1.
General Information
1A. Introduction
The DuraFlow water heater / buffer was
designed and developed specificaly as a companion
for modern low mass, high efficiency heating boilers.
When piped between the supply and return it
provides a twenty gallon buffer in the hydronic
system. This is typically required in systems with
three or more zones to store and release heating
capacity when only a single zone is operating.
As a water heater, it utilizes the rapid heat-up
ability of low mass boilers to immediately convert this
energy to a steady state continuous domestic output.
In single residential applications when provided
with a properly piped mixing valve and flow restrictor
(see Figure 2) it is the hot water source with a twenty
year warranty.
1B. Piping
When the DuraFlow is utilized as a domestic
water indirect, it may be piped as a zoned indirect
utilizing conventional circulator or zone valve piping
and wired with domestic water priority. In this and
buffer applications, the DuraFlow must always be
piped with a thermally trapped tempering valve and
flow restrictor set for applicable boiler input.
When utilized as both a buffer and a domestic
water indirect, the DuraFlow is piped to the heating
system supply and return headers or as the bypass on
systems requiring primary / secondary piping. No
zone valve or circulator should be piped in series with
the DuraFlow. In most applications the boiler pump
(internal or external) serves as the flow means
between the boiler and tank when used as a buffer.
In multi-unit residential applications with a
single hydronic heating system, it serves as the heat
exchanger source for single or multi tank domestic
water storage.
When piped as a buffer and an indirect domestic
water source to a storage tank, a tempering valve and a
flow restrictor are not required.
Figure 1. Dimensions and Connections.
*Minimum Clearance
Dimension
Figure 2. Domestic Hot Water Piping.
STORAGE
TANK
OPTION 1
COLD
DURAFLOW
PRESSURE
RELIEF VALVE
AQUASTAT
RECOMMENDED
ANTI-SCALD VALVE
SUCH AS SPARCO
OR DANFOSS
REQUIRED
FLOW
RESTRICTOR
(SUPPLIED)
OPTIONAL RETURN LINE PIPING
OPTION 2
ALTERNATIVE APPLICATIONS
OUT OF
PRODUCTION