Inlet And Outlet Connections; Minimum Pipe Size Requirements; Primary Heat Exchanger; Low Water Temperature Systems - Camus Hydronics DynaFlame DFW501 Installation, Operation And Service Manual

4.3

INLET AND OUTLET CONNECTIONS

•
All water connections meet American National
Standard Pipe Threads (NPT).
•
For ease of service, install unions on inlet and outlet of
the appliance. The connection to the appliance marked
"Inlet" on the header should be used for return from the
system. The connection on the header marked "Outlet"
is to be connected to the supply side of the system.
4.4

MINIMUM PIPE SIZE REQUIREMENTS

Minimum water pipe connections are as follow for
DynaFlame for single unit installations. The equivalent
number of straight feet of pipe for each valve and fitting in
the connecting piping must be considered to properly arrive
at the total equivalent feet of straight pipe in the field
installed piping to the appliance. See the piping
requirements in Part 11 - Installation section of this manual.
Consult factory if longer piping distances are required for a
specific application.
4.5

PRIMARY HEAT EXCHANGER

This appliance uses copper finned tubing to maximize the
heat transfer process. The primary heat exchanger is
comprised of vertical tubes rolled directly into two circular
bronze headers. This heat exchanger is design to withstand
160 PSIG working pressure. A series of "V" shaped baffles
are installed between the individual tubes to control the
movement of the flue products over the finned tubes to
maximize efficiencies.
A factory recommended circulating pump ensures proper
water flow during burner operation and creates enough
water turbulence inside the copper tubes and header that
prevents the formation of sediments. Temperature rise and
erosion prevention in the primary heat exchanger are
controlled by the selection of a properly sized circulating
pump. To ensure proper operation and ensure longevity of
this heat exchanger minimum inlet water temperatures of
115ºF (46ºC) MUST BE maintained for non-condensing
models and 130 ºF (55ºC) for near-condensing and
condensing models.
When return water temperatures are below the
recommended temperature, the flue products passing
through the copper finned tubes will be cooled below their
dew point resulting in the formation of corrosive
condensation on the copper which shorten its life. Under
these conditions condensation will collect in the base of the
inner combustion chamber. Follow the piping
recommendations given for low water temperature systems
if water temperatures are expected to be below the
recommended value. During initial operation of the
appliance in a cold system some condensation will be
generated but it will be quickly evaporated once the system
return temperature reaches 115ºF (46ºC).
Return Water Temperatures Required for Dynaflame
Boilers & Water Heaters
Minimum acceptable return water temperatures are
determined by the category of the heater. This is
true for all manufacturers.
A category I machine like the non-condensing version of
the Dynaflame 85% efficient model can be operated with
return water temperatures as low as 115ºF (46
that the control algorithm is correct. Proper operation
requires initial startup of the machine followed by ramp up
to high fire. This sequence minimizes initial condensation
and generates stack temperatures which dry up initial
condensation in the vent.
Category II machines like the near condensing version
Dynaflame 88% efficient model (DFX) and the condensing
DynaFlame 95% efficient can be operated down to 20%
firing rate from initial startup. These machines must be
operated with a return water temp of at least 130ºF (55
to the primary heat exchanger in order to avoid
condensation there. For these appliances condensation in
the vent is not an issue because they are installed with a
special venting system designed to withstand the corrosive
action of condensate.
The Camus designs are versatile and user friendly, they
deliver optimal performance by taking full advantage of
existing site conditions in order to maximize energy
savings.
Operating this appliance at return water temperatures
below
up) may cause primary heat exchanger to fail and may
eventually cause hazardous conditions that may result in
personal injury or non-warrantable damage to the unit.
4.6
In applications where the heating system requires supply
water temperatures below the recommended temperature,
a bypass line must be installed upstream of the appliance
pump so that outlet water can be re-circulated to raise the
inlet temp to a minimum of the recommended temperature.
Balancing valves, preferably circuit setter or globe valves
are used to adjust flow. (See Figure 9)
Figure 14: typical Low-Water Temperature System
Adjustment Procedure.
a)
b)
c)
d)
o
C) provided
IMPORTANT
the recommended temperature (except initial heat

LOW WATER TEMPERATURE SYSTEMS

(Non-Condensing)
Fully open bypass and outlet valves.
With appliance running,
temperature after 15 minutes.
If inlet temperature is less than the recommended
temperature slowly close outlet valve until the inlet
temperature climbs to slightly above the recommended
temperature.
If inlet temperature is greater than the recommended
temperature but not greater than 140° F no further
adjustment is required.
o
C)
read appliance inlet
18